How to get perfect UV sphere Mercator projection?

Question: I'm trying to unwrap a UV Sphere and I can't seem to get a perfect Mercator projection. What process should I follow to get a perfect UV unwrap that looks like the black grid lines in this image?:
Comment: Does aligning the view to the equator then pressing `U` _> Sphere projection_ or *Cylinder projection* work?
Comment: Sort of, but the top and bottom parts are offset and each horizontal line is spaced evenly instead of exponentially. See http://i.stack.imgur.com/ZH4HL.png
Comment: @Keavon I don't think it is possible to get exponentially spaced UVs without altering the map or the object. Hopefully my answer is along the lines of what you want which is basically unwrapping a sphere.
Comment: related: http://blender.stackexchange.com/questions/10741/what-is-the-best-way-to-unwrap-a-sphere
Answer: Update:
Newer versions of Blender now come with a Generate UVs checkbox (that can do as the name says and provides pretty decent maps) when adding a new mesh for most of the objects. Simply access this from the F6 menu or the toolshelf. This option is only available when generating a new object. The layout is below, still not perfect but useful nonetheless .

Add a UV Sphere to the scene and select an edge with AltRMB, next enter Face selection mode and select a face near the edge you marked. Next hit A to select the entire sphere and hit U > Follow Active Quads.

Note the grayed face near the middle of the sphere along the edge, this means that it had been selected before you selected the entire sphere and this is similar to what you should have done.
After unwrapping, you should get a huge UV map in the Image Editor. Transform it as desired, I would recommend aligning one corner of the map to a corner of the image and scaling it via the 2D Cursor.

A perfectly unwrapped sphere sans exponentially spaced UVs which aren't possible unless you tweak the map afterwards or modify the object's geometry.

You might notice a sharp seam near the top of your sphere where the texture stops. This is caused by the geometry of the sphere as the top vertices merge into a single point and the unwrap method basically ignores it.

To fix, just get an edge ring as close as you can to the middle vertex so that it won't be noticeable.
Comment: @helpMePlease I mean that you can select the entire UV by pressing _A_ and then translate a corner of it into a corner of the canvas over the image. Once there, go to the header of the UV window and change the pivot point (a box with a blue circle in it) to _2D cursor_. You can then scale the image from that point of the canvas, it's completely optional but makes scaling/adjusting the image a bit easier
Comment: What about a script taht simply sqares the v coordinates?
Comment: I just found the topic, because I have to solve the same problem and I could follow the tutorial that far but I have one more question.
You write "Transform it as desired, I would recommend aligning one corner of the map to a corner of the image and scaling it via the 2D Cursor."
But how does this work? How can I align the corner of the map to the corner of the image? Thanks for help!
Comment: To avoid the problem at poles, you can create a sphere that is all quads. To do that, create a circle. Enter vertex mode and delete the top half of the circle, but leave the leftmost and rightmost vertices. Select a view where the circle looks like a half line (Numpad 3 did this in my case), select all and click Spin. Select -360d as angle and adjust other parameters as needed. Enter edge mode, uncheck Limit Selection to Visible, and shift+alt+click on the starting edge (the number of selected vertices should double). Now remove doubles. Done, you have a sphere where even the poles are quads.
Comment: @PedroGimeno I think you should write an answer if you can. Thanks.
Comment: It's in no way a complete answer. That merely replaces the very first step in your answer, "Add a UV sphere to the scene". The rest would be identical to your answer, and I don't want to copy it of course. I'm also lazy to make captures O:)
Answer: Mercator Projection Addon

Install the addon.
To use the addon, have a spherical mesh in edit mode.  From Mesh > UV unwrap menu choose Mercator Project
Set the minimum and maximum latitudes of your mercator map, in the example image world map that's from -69.814 degrees (south), to 85 degrees north.  The code selects all verts within this range (inclusive) and maps a UV.
The poles have an infinite mapping, and hence are not mapped.
Currently the object's origin needs to be in centre.
Will expand more later.
Addon code at github
Comment: that looks awesome !
A good addition would be a way to calculate the min/max latitudes from the image's aspect ratio like I did with my script
Comment: @ChameleonScales Actually used an edited version of your code,  except selected  a point on equator, and inverse function to calculate for  north and  south, (instead of assuming equivalence).  I'm making a suite of geographic projections using [this tome](https://www.google.com.au/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=0ahUKEwi7l9Xr6MDWAhUJHpQKHUMODW4QFgguMAE&url=https%3A%2F%2Fpubs.usgs.gov%2Fpp%2F1395%2Freport.pdf&usg=AFQjCNEftDeYZIiyoiK0MzhIrYfoQ77Hag)
Comment: (long link) continued... Might put together a reverse UV that  makes a sphere mesh from the map, which would allow for creating the correct N and S latitudes when creating the mesh.   (eg those you chopped off)
Answer: As you know, a full Mercator projection expands vertically to infinity, so it always has to be truncated on the latitude and different images use different truncation angles. So I made 2 scripts :

one that determines the truncated angle based on the aspect ratio of your image (in case you don't already know that angle). Of course your image must not have any added border (like the black and white checker border on the image you posted in your question).
and one that distorts your UV map from an equirectangular projection to a Mercator projection.

Note that some images are not even truncated at the same angle between North and South. For those you have to extend the canvas of the image so the equator is in the middle.
Here's how to do the whole thing :

Open Blender from the terminal (e.g on Windows run cmd and enter blender.exe)
open this file from it :
There's an empty mesh object named "Sphere". While staying in edit mode, create a UV sphere (this way it already has the material assigned to it). Tweak the number of segments and rings to whatever you want. For your first time I recommend matching the grid on the image to really see that it works, which would be 24 segments and 12 rings. And don't generate UVs.

in the object named Truncator there are 3 modifiers. Expand the 2nd one and in the "Steps" property, enter the same number as the number of segments in your sphere (like 24).

If you already know the latitude angle at which your image is truncated, skip this step. If you don't, read the description of the script named "Truncated angle calculation" in the Text Editor and once you've done that, run it and look at your terminal.

now that you know the truncated angle from the poles, copy it in the X rotation of the Empty object named "Truncated angle" (currently set to 12.5°)

add a boolean modifier to the sphere :

Operation : Difference
Object : Truncator
Solver : Carve

select the first layer of the scene to hide the Truncator
apply the boolean modifier

in Edit mode, select everything by pressing A twice and do a Ctrl+V > Remove Doubles
delete the vertex at the center of the sphere

select everything and do a U > Sphere Projection :

Direction : Align to object
Correct Aspect : unchecked

if one or several faces of your UV map are moved to the other side on X, select them, press Y to separate, then G and move them anywhere outside, then select the edges that should connect to the grid and hit V and left click to Stitch.

go in Object mode and Material shading
in the Text Editor select the other script, named Mercatorizer and read its description.
run the script
go in edit mode and zoom on the timage to see that the UV map matches the grid of the image.

Now you can do this with any image and any sphere resolution.
Have fun Mercatorizing !


What version of Adobe Illustrator do I need to downsave my files to (for customers) in order for all versions to be compatible?

Question: I am busy designing illustrations in Adobe Illustrator for a customer, and they have kindly asked me to save my illustrator files so it is compatible with all versions, and they don't run into any problems. I would just like to know which version I should save it as? The options are: CS6, CS5, CS4, CS3, CS2, CS, Illustrator 10, 9, 8, 3, and Japanese illustrator 3.
Comment: When you get requirements, its your job to get them clarified. We can not solve this for you sine we do not know what problem your client is trying to solve with this. Ask them.
Answer: Well there's no such thing as "compatible with all versions".
If you save to a legacy version, often artwork can be expanded/flatted or otherwise changed in order for it to be read by the legacy version. How much anything changes depends greatly upon the actual construction within Illustrator.

In many instances, the best balance between compatibility and construction retention is an Illustrator 8 EPS file. But, be aware, saving to AI8 will, in all probability alter the artwork - especially if you used things like transparency and blending modes.

For a direct Illustrator to Illustrator transfer, Illustrator CS6 will work better than the AI8 EPS. But, of course, this assumes users are using CS6 or newer. But, this avoids any "subscription-based" version, which is common.

A third option is merely a PDF. Since all PDFs can be opened in Illustrator, you may experience the optimum transfer by merely saving the AI file as a high quality PDF. Then whatever version of Illustrator is in use later, will read and adjust the PDF artwork as necessary. Saving as a PDF will often be as compatible as AI8 EPS, if not more so because PDF will retain much of the artwork construction as it is.

I'll stress again that "compatible with all versions" isn't "real-world" feasible.  You must set a minimum. No one using a computer operating system released in the last 10 years can run any version of the application older than CS6. There's little point to saving to any legacy version other than CS6 if you are saving as an .ai file. However, some third-party software, such as embroidery or engraving applications, can only see EPS files. So, that's where AI8 EPS comes in.
Knowing the expected usage would assist in targeting the version appropriately, or you may consider merely saving as CS6, AI8 EPS, and high quality PDF, and a native file for whatever version of Ai you are using for each piece and providing 4 files for each illustration. After all saving as another version is a few seconds for you, but compatibility issues later may cost someone hours or days to get around.
Comment: I agree. The biggest problem is that it does not even solve any of the issues about having native file formats can bring you. If I save as illustrator 8 ai file (which is annotated eps), ive probably lost any of the advantage of a modern illsutrator simply because the file does not support modern AI very well.
Answer: This is an unusual situation. Typically, Illustrator is the "creators" domain and the "user" would be provided with a .pdf or a file type that is adaptable for their needs (resizing, etc.).
Maybe you are only doing some initial conceptual Illustrations that then someone else will need to rework and/or modify them further in Illustrator? It is hard to say without some more info as to the reason they are wanting the AI files.
AI files in the hands of a client can create nightmares when going to production. Not to mention that as the designer you should be the one working the original AI files (for yours and for their benefit).
All that being said, probably backward compatibility to CS6 is sufficient for most needs. It seems there is a great dividing line of people using the CC subscription versions and the people who did want to go there and are still using CS6. Anything earlier than that, in most cases, would have some limits functionally (again, depending on how your illustrations are constructed).
Depending on your Illustrations, there may be some "new" features of the CC versions that will not come through in the CS6 version- this would need to be checked before you provide the files.
Answer: Read between the lines..
Your client probably just needs to be on the safe side without knowing what to ask for specifically. More so, when things are not made 100% clear, you should also play it "as-it-is" and just send whatever you think that's most likely to be needed.
Your client will probably never open these files and just wants a local backup to "not run into any problems". This, in most cases, means they need the files in case you terminate the contract and never speak to them again.
And no, they do not have separate computers in the office running every version or AI. They do not have a computer with a CS6 licence, another one with a CS5 licence, another with a CS4, CS3 and so on. You get the idea :)
I have seen a lot of these requests and in my experience this should be interpreted as sending everything in CS6 format. It is very unlikely anyone still actively designing today to be using any kind of Illustrator older than CS6.
So..
Send in CS6, and if they have anything to say about that, they will. Otherwise, it will just be done.
Comment: Why not? I am designing in 5.5
Comment: I don't have statistics, but you must be among those few that still actively use anything pre-CS6. Even so, this is beyond the scope in question, as the OP's client is likely never opening the files and just asking for internal backup. And yes, CS6 is 100% the "safest bet", as also mentioned in the other answers.
Comment: Yeah i get that, but i would know to specify version.


Should I use single or double colon notation for pseudo-elements?

Question: Since IE7 and IE8 don't support the double-colon notation for pseudo-elements (e.g. ::after or ::first-letter), and since modern browsers support the single-colon notation (e.g. :after) for backwards compatibility, should I use solely the single-colon notation and when IE8's market share drops to a negligible level go back and find/replace in my code base?  Or should I include both:
.foo:after,
.foo::after { /*styles*/ }

Using double alone seems silly if I care about IE8 users (the poor dears).
Answer: Do not use both combined with a comma. A CSS 2.1 compliant (not CSS3 capable) user agent will ignore the whole rule:

When a user agent cannot parse the selector (i.e., it is not valid CSS 2.1), it must ignore the selector and the following declaration block (if any) as well.
CSS 2.1 gives a special meaning to the comma (,) in selectors. However, since it is not known if the comma may acquire other meanings in future updates of CSS, the whole statement should be ignored if there is an error anywhere in the selector, even though the rest of the selector may look reasonable in CSS 2.1.

http://www.w3.org/TR/CSS2/syndata.html#rule-sets
You could however use
.foo:after { /*styles*/ }
.foo::after { /*styles*/ }

On the other hand this is more verbose than necessary; for now, you can stick with the one-colon notation.
Comment: thanks for including the info on the comma and the ignore.  That probably would have had me (and maybe others) scratching heads for a while.  Looks like the best thing when 99% of browsers in use do support the double colon notation is to shift to using that and (because no one will drop single colon support and break the web, so there's not really even a point in later find/replace-ing old code at that point).
Comment: This isn't the way forward. Browser progress will be forcibly expedited if people stop pandering to antediluvian, broken, and deprecated browsers.
Comment: @Gershom Maes: That's not for you to say, unfortunately. I think a large portion of developers hope for the same, but it's just not gonna happen.
Comment: I think it's important to note that maintaining duplicate styles can be problematic.  As cHao notes below, duplicate code loves to diverge.  Most developers probably have to be bitten by it a few times to swear it off :)
Answer: From CSS3 Selectors REC:

This :: notation is introduced by the current document in order to establish a discrimination between pseudo-classes and pseudo-elements.
  For compatibility with existing style sheets, user agents must also accept the previous one-colon notation for pseudo-elements introduced in CSS levels 1 and 2 (namely, :first-line, :first-letter, :before and :after).
  This compatibility is not allowed for the new pseudo-elements introduced in this specification.

It seems you're safe using (only) one-colon notation for pseudo-elements that already existed in CSS2.1 as UAs must be backward compatible.
Comment: For the record, this answer could equally well be marked as correct.  It provides some valuable perspective, even though the impetus for the original question was specifically the before and after pseudo-elements.  Thanks for adding it.
Comment: How did you come to that conclusion? I came to the opposite conclusion... if single colons will **not be allowed** for new pseudo-elements, shouldn't you start using double colons to get in the habit?
Comment: @andrewtweber in context of the original question (IE8) using double would break the CSS.  That said, as of this writing most sites probably see IE8 usage at such a low level as to allow double without any significant fallout.  Browser vendors may be relied upon to support the single notation in perpetuity, but nothing wrong with switching coding habits at this point.
Comment: @andrewtweber +1 for OP Yep, IE8 was to be taken into account in 2012 and - YMMV - is still in 2015 in huge B2B projects and alike but not in other web projects. Both notations are perfectly valid for these existing pseudos. CSS minification will gain 1 byte by using one-colon notation. If you want to always use one notation and forbid the other, well that's a convention you're completely free to do so with your team but it's not a RECommendation.
Comment: @jinglesthula and Felipe, you're right, I didn't notice the date. Maybe the answer should be updated though, since this question comes up high in search results
Comment: @FelipeAls Wouldn't it be best to only use the double-colon notation for all pseudo-elements and let the CSS minifier reduce the syntax in an automated build task? [cssnano](http://cssnano.co/) lists this as one of it's features on the homepage: "Pseudo element double-colon syntax reduction".
Comment: @Ronald That's a convention you can adopt but it isn't "better" (or worse). If you still support IE8 (my sincere thoughts and), you'd better use single-colon and make sure Autoprefixer replaces double-colon by single ones otherwise it's a matter of taste. I'm very accustomed to single-colon because even IE7 didn't exist when I begun professionally but that's just a personal habit.
Answer: I absolutely disagree with @mddw and @FelipeAls, in regards to considering the use of one colon "safe".
This "I'll use it even though it's deprecated" mentality is exactly why browser-based technologies are so slow at advancing and progressing forward.
YES, we want to maintain compatibility with old standards. Let's face it, it's the hand we've been dealt. BUT, this does not mean you have an excuse to be lazy in your development, by ignoring current standards in favor of deprecated ones.
Out goal should be to maintain compliance with current standards, while supporting as much of the legacy standard as possible.
If pseudo-elements use : in CSS2 and :: in CSS3, we should not be using one or the other; we should be using both.
To fully answer the original question asked, the following is the most appropriate method of supporting the most current implementation of CSS (version 3), while retaining legacy support for version 2.
.foo:after {
  /* styles */
}
.foo::after {
  /* same styles as above. */
}

Comment: If you "*absolutely disagree*" with my answer, then you're absolutely disagreeing with the word *must* in a W3C RECommendation. "*Out goal should be to maintain compliance with current standards, while supporting as much of the legacy standard as possible.*" is what is being addressed by this part of the REC and it explicitly states that UAs mustn't force authors to use both notations and explains how this must be done by these UAs. Feel free to contact CSS WG mailing-list if you're not OK with that (or on Twitter @glazou co-chairman of this Working Group)
Comment: @JoshuaBurns If my predecessor had duplicated a load of code to protect against an imaginary future threat I would feel significantly more "screwed".
Comment: I don't disagree with your entire answer, only regarding the use of a single colon as "safe". **compatibility is not allowed for the new pseudo-elements** means any future pseudo-elements will only be implemented in `::`. According to your approach, individuals will then start to mix-and-match the use of `:` and `::` for pseudo-elements. Adhering explicitly to old standard (which for the time being may be supported,) is an inherently bad practice and should be avoided whenever reasonably possible. If you disagree with that statement, we simply hold different views.
Comment: Adhering to an *explicitly compatible* standard is inherently *not* a bad practice, if compatibility is a goal.  On the other hand, using both leads to duplicate styles -- and as anyone who's coded for a while knows, duplicated code just loves to diverge.
Comment: I think it is pretty safe to assume that browser vendors will continue to support the old notation indefinitely due to the amount of code that will realistically never be updated that they want their browser to render 'correctly'.  On the other hand, maintaining separate copies of the styles raises the DRY red flag, I think.  I think it's more pragmatic than lazy to use the single-colon notation until IE7 market-share drops off.  That said, I want the web to move forward as much as anyone!
Comment: If you really want to use both notations, you can throw all your rules with the old notation into a separate stylesheet reserved for IE8 and older with a conditional comment, since those are the only browsers/versions that are still relevant at the time of this writing that support the old notation without supporting the new one. From a pragmatic stance, it is utterly pointless to include both notations in the same stylesheet unless you're a wizard with PE or GD or whatever with CSS and can figure out a way to make the legacy pseudo-elements relevant even when CSS3 features are not supported.
Comment: @Mark Amery, betting on something you have no control over or view into the future of is a foolish practice. As a programmer, you can do the minimum, the good enough; but that sort of programming ends up screwing anyone who inherits your projects in the future.
Comment: @BoltClock that is a great suggestion, as most interfaces of any complexity end up with IE-specific stylesheets anyways.
Comment: -1. Yes, eventually we want developers to stop using the legacy selectors (since they break the otherwise-elegant system of using single colons for pseudo-classes and double colons for pseudo-elements). However, how soon that happens is *not affected at all* by whether developers right now use only the single colon syntax or use both. To support legacy documents, new browsers will need to support this syntax forever anyway - but once IE 8 finally dies, web developers can abandon the single-colon syntax forever. What advantage is gained from people using both syntaxes in the interim?
Comment: @Mark Amery: Forward compatibility. Why wait until IE8 dies to implement the appropriate syntax?
Comment: @JoshuaBurns There is no forward compatibility issue, here, though. Browsers - and the CSS spec - will likely *never* be able to drop support for the old syntax, because there are documents out there that use it that are unmaintained and will never be updated. There is no reason to fear that some day the old syntax will cease to work.
Comment: I always prefer to keep the most recent notation as the last line. By doing so, you make sure that the latest standard is always used. In your code example, the "old" CSS 2.1 standard will always be used (as long as the browser supports it).
Answer: However, it's become increasingly popular to use polyfills for both new javascript and CSS, so you might just want to stick with using the newer double-colon (::) syntax, and maintain a polyfill for older browsers, so long as that is necessary.
Comment: eh, the first part may be meta, but I think the second part is a good answer.  Where I work we don't use a preprocessor and/or polyfills, so the accepted answer works for me.  But for any shop or dev that uses such tools, this answer is probably more useful.
Comment: why not also link such a polyfill, so we can use it without further googling?
Comment: This is essentially just a meta answer; it doesn't provide any useful information. If an answer is outdated, downvote it and/or comment on it indicating such.
Answer: For what it's worth according to Browser Stats IE 8.0 has dropped to less than 1% in the USA over the past year.
http://gs.statcounter.com/browser-version-partially-combined-market-share/desktop/united-states-of-america/#monthly-201512-201612
In December 2015 IE 8.0 had 2.92% of the market.
In December 2016 IE 8.0 had .77% of the market.
At that rate of decline it wouldn't be the worst idea to stop supporting old versions of IE and start using :: for Pseudo Elements.
Comment: Which is something to celebrate :)  It's also worth pointing out that it depends on the situation still.  If you're Amazon, 0.5% of your users equals over a million customers who think your site is broken.  If you're doing a blog for a 10 person startup, the stakes may be different.
Comment: Definitely true about an organization like Amazon.  But that .77% isn't evenly distributed across the entire population.  It's disproportionately old folks or people with little money that can't upgrade.  From a purely business standpoint those probably aren't ideal target markets.  So to most companies the .77% group is even less significant than what that small number suggests.  And that number will only get smaller.
Comment: Good points.  Another group where upgrading is an uphill battle is government and business groups rely heavily on apps that will only work with a certain browser version (though thankfully groups that are that way will diminish over time as well).  May none of you ever have to code for such a client :)
Answer: Including both notations is certainly safer, but I can't see any browser dropping the single notation for a long time, so only a single one'll be fine (it's valid CSS2.)
Personnaly I only use the single colon notation, mostly by habit.
Comment: As the other answers make clear, it's a bit more complicated than this and there are some non-obvious traps (e.g. supporting single-colon notation for CSS 3 pseudo-elements is an explicit violation of spec, so it seems wise for CSS authors not to use the single-colon notation for those selectors).


Consequences of Blindness on casting spells?

Question: Which types of spells can a Blinded caster still target as accurately as usual? Which ones require extra steps or give penalties because of blindness? Which ones can simply not be targeted at all, thus not cast?
Answer: Range: Personal or targeted at yourself
Cast normally

Has a Target entry

You must be able to see or touch the target, and you must specifically choose that target.

When blind, your only solution is to touch the target. If you are the target, this is automatic. Otherwise, the Invisibility entry of the Glossary provides an option when the location of a target is unknown:

A creature can grope about to find an invisible creature. A character can make a touch attack with his hands or a weapon into two adjacent 5-foot squares using a standard action. If an invisible target is in the designated area, there is a 50% miss chance on the touch attack. If successful, the groping character deals no damage but has successfully pinpointed the invisible creature's current location. If the invisible creature moves, its location, obviously, is once again unknown.

Also, a creature with a normal reach hitting you reveals its position:

If an invisible creature strikes a character, the character struck knows the location of the creature that struck him (until, of course, the invisible creature moves). The only exception is if the invisible creature has a reach greater than 5 feet. In this case, the struck character knows the general location of the creature but has not pinpointed the exact location.

This would allow you to target it with a regular Touch Attack, with the usual 50% miss chance for Total Concealment.

Rays
Ray spells are considered ranged attacks and allow trying to hit unseen targets:

As with a ranged weapon, you can fire into the dark or at an invisible creature and hope you hit something. You don't have to see the creature you're trying to hit, as you do with a targeted spell. The target will have Total Concealment and a 50% miss chance, though.

Creation or Summoning

Some spells create or summon things rather than affecting things that are already present.
You must designate the location where these things are to appear, either by seeing it or defining it.

As long as you can describe the location, you can cast the spell. As such, Summoning spells can be used when blind.

Area spells
You do not need to see creatures to catch them within an Area spell. By default, you actually cannot pick which creatures are affected, just the area.
There is no indication that you need to see the point of origin of the spell:

you select the point where the spell originates
Burst, Emanation, or Spread: Most spells that affect an area function as a burst, an emanation, or a spread. In each case, you select the spell's point of origin
You must have a clear line of effect to the point of origin of any spell you cast.

You just "select" it, which I assume is the same as "designating a location" with creation and summoning spells.
Comment: Effect spells specifically say 'You must designate the location where these things are to appear, either by seeing it or defining it.' Area spells specifically don't include this text, so presumably you don't have the same restriction.
Comment: @YogoZuno: So you... don't have to designate the location of area spells? I'm confused.
Comment: I was referring more to the 'seeing or defining it' part. Although, I don't think you can get away from defining it.
Comment: @YogoZuno: That's what I was referring to, really :). Being allowed to define the spot is the least restrictive obligation there is in this case, I think.


Finding gender affinity for businesses

Question: What are the different models I can use to find the gender affinity of businesses using yelp dataset-- https://www.kaggle.com/yelp-dataset/yelp-dataset . I need to find Probablity (Male buying from a merchant) and Probablity (Female buying from a merchant) where both probablities add to 1 . There is no information about gender so I can use the Genderize api to find gender using names of users. This is an unsupervised problem
Comment: Do you just want to find the gender affinity of the businesses in the dataset?  Or are you hoping to build a model to predict gender affinity for new businesses?
Comment: just in the dataset
Answer: Since you're only interested in the gender affinity of businesses in your dataset, no model is needed.  You can compute gender affinity directly:  For each business, find the total number of customers, the total number of male customers, and the total number of female customers.  Then $Pr(Male) = \frac{males}{total}$ and $Pr(Female) = \frac{females}{total}$

Finding gender affinity for businesses


Converting trunk interface to be in an ether-channel mode between cisco 3650 and 4500X

Question: I currently have an interface on each switch configured as a trunk between the two switches. I want to now add another interface on each switch to increase the bandwidth between the two. I am thinking about using a port channel, and assigning these ports to the port channel. Will I lose connectivity (temporarily) between the two switches when I do this?
Comment: Did any answer help you? If so, you should accept the answer so that the question doesn't keep popping up forever, looking for an answer. Alternatively, you can provide your own answer and accept it.
Answer: Best way (no headache) is to default and shut the member interfaces , create the port-channel , add the member interfaces to the port-channel , no shut and only after that add the trunk configuration on the port-channel (the vlans).
There are numberous issues and tricks even when working between switches from the same vendor , like surprises after a reboot when you get different configurations between the port-channel and the member interfaces , leaving you with error-disabled interfaces or unbundled from the Po.
Comment: Thanks for the responses. I tested this out on non-production switches and it definitely loses connectivity.
Answer: The link will probably glitch when you do this, and if you make an error, you will likely send ports into err-disable. The real way to do this is to shut the ports down, build the port channel interface, add the ports to the channel, then bring up the ports.
Also, understand that you will not increase the usable bandwidth for a single data flow. Each flow will only use one of the links in a port channel.
Comment: Thanks Ron for your input. When you say a glitch even if I didn't make a mistake, are you saying I would lose connectivity between the two switches from how they are working no to when they are in etherchannel mode?
Comment: Even in the best scenario, it will probably drop some frames.
Answer: Expect to lose connectivity - briefly.  Configure a port-channel interface on both switches and configure it as a trunk.  You might try and specify dot1q trunk.
Configure the new ports with channel group and set mode to "on" and trunk mode.  Shutdown the interface via the command line.  Do the same on the near side switch.  unshut on the far end, then unshut on the near end.
Done.  If you don't shut/no shut the interfaces - they may never come up as they will be errdisable.
Both sides mode "on".  Shut/No shut.


Iptables overridden after reboot in Ubuntu server

Question: On my Ubuntu server (installed KVM and Kimchi), I noticed that the iptables are changed after a reboot. Unfortunately I did not find out which script is responsible for these changes.
I tried to store my own settings in `/etc/iptables/rules.v4? and bring them back after reboots by adding
/sbin/iptables-restore < /etc/iptables/rules.v4

to /etc/rc.local. When I manually execute this line, it works properly. But when I rebooted the machine again, my settings were overridden by the other script again. I conclude that my line from /etc/rc.localis executed before this external script, hence overridden.
Which one could it be and how could I find it out?
Answer: Most likely this is UFW, Ubuntu's own firewall control software.
Comment: No, it says that it is disabled?


Dedekind domain with a finite number of prime ideals is principal

Question: I am reading a proof of this result that uses the Chinese Remainder Theorem on (the finite number of) prime ideals $P_i$. In order to apply CRT we should assume that the prime ideals are coprime, i.e. the ring is equal to $P_h + P_k$ for $h \neq k$, but I can't see it. How does it follow?
Answer: Here's one proof. Let $R$ be a Dedekind ring and assume that the prime ideals are $\mathfrak{p}_1,\ldots,\mathfrak{p}_n$. Then $\mathfrak{p}_1^2,\mathfrak{p}_2,\ldots,\mathfrak{p}_n$ are coprime. Pick an element $\pi \in \mathfrak{p}_1\setminus \mathfrak{p}_1^2$ and by CRT you can find an $x\in R$ s.t.
$$ x\equiv \pi\,(\textrm{mod } \mathfrak{p}_1^2),\;\; x\equiv 1\,(\textrm{mod } \mathfrak{p}_k),\; k=2,\ldots,n $$
Factoring we must have $(x)=\mathfrak{p}_1$. It follows that all prime ideals are principal, so all ideals are principal and $R$ is a PID.
EDIT: The definition of a Dedekind domain is a Noetherian integrally closed, integral domain of dimension 1. The last condition means precisely that every nonzero prime ideal is maximal, so maximality of nonzero primes is tautological. Maximal ideals are always coprime.
Comment: If $M_1$ and $M_2$ are distinct maximal ideals, then $M_1+M_2=R$ because $M_1+M_2$ is an ideal (sum of two ideals is an ideal) that properly contains the maximal ideal $M_1$ (as it contains both $M_1$ and $M_2$, and $M_2\not\subset M_1$).
Comment: Sorry, I really mean why are the $P$ 's coprime? (In the sense that the sum of two of them gives the entire ring.)
Answer: Different prime ideals are coprime because in a Dedekind domain every nonzero prime ideal is maximal. If $P$ and $Q$ are nonzero prime ideals then $P+Q$ is an ideal containing both $P$ and $Q$ and so must be the whole ring if $P\ne Q$.
Comment: I'd like to make a comment that probably would make my question less trivial. I note that all of your answers are taking as granted that the ideals are maximal. From the definition I read it is not immediate to me why those ideals are maximal.
Comment: Btw, the definition says: a Dedekind ring is an integral domain with unit such that every proper ideal is (in a unique way) a product of prime ideals.
Comment: @Lmn6: That's OK, because remember that saying an ideal $\mathfrak{p}$ divides an ideal $\mathfrak{q}$ is the same as saying $\mathfrak{q}\subset \mathfrak{p}$.
Comment: @Lmn6, there are [several equivalent definitions of Dedekind domains](http://en.wikipedia.org/wiki/Dedekind_domain#Alternative_definitions). One of them is "integrally closed Noetherian domain with Krull dimension one (i.e., every nonzero prime ideal is maximal)."
Comment: @SteveD: Yes, but your argument should work assumed that the prime ideals we are talking about are principal. But I don't know if that is the case; does it follow straight from the definition?
Comment: @Lmn6: You don't need them to be principal. I'm not sure what you're saying, actually.
Answer: Hint $\ $ Nonzero prime ideals are maximal, hence comaximal $\, P + Q\ =\ 1\, $ if $\, P\ne Q.$
Another (perhaps more natural) way to deduce that semi-local Dedekind domains are PIDs is to exploit the local characterization of invertibility of ideals. This yields a simpler yet more general result, see the theorem below from Kaplansky, Commutative Rings. A couple theorems later is the fundamental result that a finitely generated ideal in a domain is invertible iff it is locally principal. Therefore, in Noetherian domains, invertible ideals are global generalizations of principal ideals. To best conceptually comprehend such results it is essential to understand the local-global perspective.


How to replace a razor only outlet with a gfci

Question: So when I opened the razor only outlet, I found 2 wires connected to either a pair of white and black wires. I'm not sure how to determine which white goes with which black. Help?
Answer: Disconnect to two black wires that go to the back of the outlet and add a white wire and a black where there instead, matching the colors of the existing wires. Connect these new wires to the back of the GFCI at the line terminals.
to make this work you're probably going to need a new cover on that electrical box too, some sort of flat mud ring.
Get some white glue and dilute it 50% with water and use that to stick the torn paper back down.


Meaning of "all day long" as used by Bradley Walsh

Question: In the TV series The Chase, presenter Bradley Walsh frequently uses the phrase 'all day long'.  In the situations when he uses it, I would expect 'perfect' or 'dead right'.   Is that a meaning for 'all day long', and if so, where is it from?   I am an English teacher and I had never heard this usage until I first watched the programme about 3 months ago.
Comment: "All day long" is a common idiom which literally means what it says -- the activity went on all day.  But it is sometimes used to mean that some concept that has been stated is considered reliably true -- it was true this morning, it's true now, and it will be true tonight.
Comment: 'Yahoo Answers' gives the answer.
Answer: "all day long" is a very affirmative expression.
if someone who loved jelly beans were asked, "would you like a free delivery of jelly beans?", that person could easily respond, "all day long."
similarly, someone who enjoyed festivities, when asked if she might like to attend a party that night, could answer, "all day long," which, rather than showing literal accuracy, would impart a level of enthusiasm.
Comment: Hello, john. ELU prefers answers backed by supporting evidence; answers lacking such may just be opinion.
Comment: This answer,   as informative as it is, could be improved by a link to a source that supports its claim.
Comment: Yes, Edwin… and though Hot Licks's and john fremont's Comments make perfact sense, in 60 years I've never noticed anyone saying *all day long*, nor anything like it. the closest things I can think of are *all the life-long day* and *at the end of the day* and I don't think either has even a similar, let alone the same meaning


Is there a way to highlight text in a received email in Gmail?

Question: I'd like to be able to highlight portions of text in emails I receive from other people, in Gmail. When I reopen those emails (often large), I'd like to be able to see what portions of text I had previously highlighted.
Answer: Not with Gmail all by itself. You can't edit messages once sent/received. At best, you can forward the email message to yourself with the text highlighting you want.
Otherwise, you'll need to look for a third-party solution.
Answer: Not within the Gmail web client. I would recommend creating a Google Doc, pasting the contents of the message into it and marking it up there.
You could then take the URL of the Doc and put it in a reply to that Gmail thread addressed only to you as a quick way of referencing it in Gmail.
If a group of people are collaborating on this content, using a Google Doc instead of an email thread may be a faster, more efficient way of getting the work done.
Answer: A browser extension for easily doing that can be programmed. Until someone does that, here's a more tedious method from here for editing emails:

In Thunderbird, copy the email from Gmail IMAP to a Local folder
Delete the original email in Gmail client
Edit the email in the Thunderbird Local folder with "Header Tools Improved"
Move this email from Local folder back to IMAP

For each part of the email you want to highlight, add for example  before and  after that part of the email.
Each such part ideally shouldn't contain unbalanced HTML tags nor block HTML elements; if you don't know what that means, then more generally don't try to highlight the code characters < nor > that aren't visible in the email anyway.
So if you want to highlight the end of one paragraph and the beginning of the next paragraph, and the paragraphs are separated by something like
,
,
, and/or
, highlight the end of one paragraph using  and , and separately highlight the beginning of the next paragraph using  and .
Answer: As a workaround, forward the email to yourself and highlight those parts (or delete the other parts) before sending it.
In that forwarded email, you can also add some text to remind you to click the "..." button to show the forwarded text because Gmail usually automatically hides that text.
Answer: Just found a way of highlighting text in my received emails (Gmail) by using Highlighter + Notes, a Firefox add-on (there might be versions to other browsers, but I'm not sure).


Does potential energy increase inertial mass of system?

Question: For example, we have a ball with mass m lying on the Earth. Then we lift it to a height h. So, now system Earth-ball have potential energy $E_p = mgh$. From Mass–energy equivalence system got $mass = \frac{E_p}{c^2}$. Does it mean that potential energy increased  inertial mass of system and it's harder to accelerate that system, or potential energy just increased rest mass of system Earth-ball?
Answer: If the energy to lift the ball came from outside of the Earth-ball system, then energy has been added to the system. And that means that the rest mass (energy) of the system has in fact increased.
Comment: Let me complete your argument. If instead it's you, staying on Earth, who lift a heavy rock, it's true that potential energy of rock-Earth system has increased, but at the expense of your internal energy. So total mass you-rock-Earth is unchanged.


How to delete a wallet

Question: I am a bit confused about the wallet location in my system.
 I have created a wallet named mywallet using cleos. then I opened eosio_wallet directory and I found mywallet.wallet file. I deleted mywallet.wallet file and run cleos wallet list command. Still, I found mywallet in the list.
Is there a way to remove the created wallet?
Comment: Did you used `--wallet-dir` to specify you wallet location generally it is located on `~/eosio-wallet`
Comment: You should first use `cleos wallet open -n your_wallet` this through the error with the path that `keosd ` is accessing, there you can delete the wallets
Answer: before deleting the wallet stop the wallet using
cleos wallet stop -n wallet_name
and then delete the wallet i guess this will help
Comment: "cleos wallet stop" works
Comment: Happy to hear that @Muhzin
Answer: From some sources I understood, Unix systems keep deleted files alive in a zombie-like state as long as any processes have them open. So deleted wallet will remain in a virtual state until keosd is killed

How to delete a wallet


computing EP messages in factor graph

Question: I'm using infer.net for implementing a dynamic Bayesian network model. every node in each layer is dependent on all nodes in previous layer (we want to train wji, the weights of edges between each node j from the previous level (time t-1) to node i in current level (time t)). node values are shown by yi (value of node i).
The dependency is a complicated function like:
yi(t) = y(t-1).(1-alpha.deltaT) + beta . 1 / (1 + exp(-WeightedSigma))
WeightedSigma = Sigma (Wij * yj(t))
Now I want to put a factor node in my factor graph implementation in infer.NET. I don't know how should I implement such factor node and its message passing. I'm so confused.
Can anyone please help me in this case?
I appreciate any help.
Thanks
Answer: The only part of this expression that you need a custom factor for is the function
$1/(1+\exp(-Sigma(x)))$.  This is a function from a scalar to a scalar, so should be relatively easy to implement using quadrature.  For examples of this approach, see section 13.8 of Bayesian Data Analysis (third edition) or section 1.4 of EP: A quick reference.
Comment: Messages to W, alpha, and beta are handled by the product factor.  Take a look at the [TrueSkill](http://research.microsoft.com/apps/pubs/default.aspx?id=67956) paper for an example of how message passing gets broken down across different factors.
Comment: Thanks for your  reply. I'm going to read the documents.
Comment: Dear Tom
How can I define the messages passed from this factor node to each Wij, and to alpha and betas? I don't know how exactly should I define messages: http://research.microsoft.com/en-us/um/cambridge/projects/infernet/docs/How%20to%20add%20a%20new%20factor%20and%20message%20operators.aspx Like in this link how they are computed after we have the distribution after removing data i (\i)? Thanks a lot
Comment: The other thing is that, I have these different variables (there are two matrices W1 and W2 which are used in this Wij*Yj term) to which I have to send messages from my factor node.
As I explained before I have 1 / (1 + exp(-WeightedSigma)){ in the formula: WeightedSigma = Sum (Wij * yj(t)) }
Now I don't understand how to propagate these messages back to these W's (elements of W1 and W2).

computing EP messages in factor graph


Dracula Cultural Anxieties

Question: I have a question on Dracula and the Victorian era. I was just wondering to what extent the cultural anxieties of the Victorian age are represented in Dracula?
Comment: What cultural anxieties would those be? What are "cultural anxieties" anyway?
Comment: @user14111: "Cultural anxieties" are anxieties that are (more) common among members of a culture.
Answer: Generally speaking, the Count seems to embody several of the anxieties of the people living through The Victorian era.  For example, they were very anxious about homosexuality, especially after the Oscar Wilde Trial. By having Dracula bite, and suck the blood of, Harker, Stoker seems to be tapping into this particular anxiety.
Victorians were also anxious about immigration and the "Other," or foreigners, who might corrupt the British population.  This may have been particularly aimed towards women who may have been attracted to foreign, tall, dark, and powerful, men. After all it is only British women, in Britain, who are bitten by a Transylvanian Dracula.
Victorians also seemed to have been anxious about the subconscious and, particularly, of losing control, through someone tapping into their minds. They seem to have feared mesmerism and hypnotism, powers akin to those Stoker assigns the Count.
They also seem to have feared the possibility of the supernatural, and any evil aspects inherent in the pursuit of "contacting" the dead. As Materialism was displacing Religion, people in the Victorian Era still seem to have believed in the immortality of the soul or the existence of spirits.  This, in addition to the possibility of electricity animating severed frog legs, (or human monsters, such as that in Mary Shelley's Frankenstein), some Victorians probably feared the possibility of somehow animating the dead, thus Stoker's "undead."
Comment: Nice answer! Could you perhaps [edit] with citations/evidence to back up your claims of various anxieties? You've demonstrated that *Dracula* has elements that connect to some anxieties which you claim existed; please demonstrate that those anxieties did indeed exist.
Comment: We expect answers to be self-contained on this site; requiring someone to look elsewhere for explanations should be avoided when possible. Perhaps you could quote the relevant sections of the biographies?
Comment: I begin my answer with the words "Generally speaking" because if one takes a perusal of one of Bram Stoker's  biographies (say, Barbara Belford's Bram Stoker) most of the above are explained.  To supplement the above, one could look at an annotated version of the text, such as  Dracula: Norton Critical Edition, which includes contextual essays as well.

Dracula Cultural Anxieties


Munkres vs Hatcher

Question: I am self-studying algebraic topology and I was wondering which book is better for my purposes. The second part of Munkres' topology deals with algebraic topology and it seems easier to understand, but I see that Hatcher is almost always the go-to textbook for the subject. However I have been having a lot of trouble with Hatcher's exercises. Can anyone with knowledge on the subject tell me which book is better suited for self study, in terms of better understanding the theory and having the better exercises?
Comment: If you have trouble, I would say that is the authors fault, not the readers fault, the real question is if there is a better book available, and unfortunately I cannot help with that. But I would say, don't torture yourself, look for something that you like better, if Hatcher doesn't work. I don't know algebraic topology, ended up teaching it once with only one student (so I had to teach both myself and the student), tried to use Hatcher (was a new book then) and didn't particularly like it. Someone wrote they don't like Munkres' style,neither do I, but I have nothing to recommend instead...
Comment: I do not own Munkres but i've spent a considerable amount of time with Hatcher's book. I think it's an incredibly great book, however, many concepts, even if pictured and organized very well are rather hard to fully understand if you are actually purely self-studying without any exposure to some concepts in a proper lecture. That's just my personal experience though. After i attended a lecture where certain concepts where explained in greater detail, i really appreciated Hatcher's book.
Answer: This is not really an answer to your question. Since you asked a soft question, call this a soft answer.
Many students, especially those who do not have some background in turning pictures into proofs (which should be taught in any first topology class but is usually not) struggle with Hatcher, as he expects a lot of these very rapid steps. A recent question also suggests that difficulty with manipulating quotient spaces.
I do not have an opinion about whether the text of the book itself is the right one for you. (Personally, I think it may be worthwhile to struggle a bit with it, but if you're not learning from it it's not ideal to waste your time. Personally, I dislike Munkres' writing. This is my taste and nothing more.)
However, Hatcher's exercises are among the most insightful introductory algebraic topology exercises I know. I think that you should do them. I think that if you're having difficulty, that strongly suggests that you could learn a lot from them! I would suggest doing the exercises no matter what books (or combination thereof; I see no harm in using multiple references, as they may explain concepts in different language, some of which may be more helpful for you) you ultimately study from.
Comment: @Chris Ewing: I don't know which recent question user905850 is referring to, but a question from a little over a year ago is a good substitute: [Hatcher Algebraic Topology: I have all the prereqs, so why is this book unreadable for me?](https://math.stackexchange.com/q/3492949/13130)
Comment: How would you recommend studying "turning pictures into proofs"? Is there some good reference in your opinion for how to learn that?
Answer: Munkres book is good for self study but in Refferences Book we can't understand all concept so you do self study if you not understand then share here

Munkres vs Hatcher


Motorcycle turn signal blinking too fast

Question: I have recently changed my turn signals as a whole as the housing got loose after years of riding. The new turn signals I ordered seem to work good, but they are blinking like 2 or 3 times faster than the previous ones, is there any real reason for this? I guess this will be due to the voltage or smth, I do not really know how the circuit is composed and what the timings depend on.
Comment: Did you unintentionally replace incandescent bulbs with LED or vice-versa?  That can cause the problem you describe.
Comment: Welcome to Motor Vehicle Maintenance & Repair! Are you seeing the same thing on both sides (left vs right)?
Comment: @Pᴀᴜʟsᴛᴇʀ2 yes, I replaced the two front lights, however when I use the old one on one side, that side works just fine, so it only happens when the new is installed.
Comment: @jwh20 definitely possible, will take a look!
Comment: Considering what you said, I'm definitely agreeing with what @jwh20 stated here in comments.
Answer: You're experiencing what most motorcycle owners would call "hyperflash" - I've dealt with it on several bikes in the past.  This generally happens after upgrading to LED's from halogen bulbs - but I suppose theoretically it could also happen in other applications.  It happens due to the voltage requirement differences between your stock and aftermarket blinkers.
The fix for this is to add a resistor to "slow" the voltage down.  Higher end aftermarket LED blinkers will sometimes have these already baked into their components but you can also splice one in downstream if it bothers you enough.  One company in particular offers a fantastic plug and play piece which I used on my most recent bike and it works great and is a 5 second install (https://tstindustries.com/tst-led-flasher-relay-gen2.html)
You can also look up the model of blinkers you purchased and I bet that same company will offer some kind of resistor to help with the hyperflash.


google hangouts gives wrong location

Question: I logged into google hangouts at my mothers house, on her tablet, through her wifi. How can google give a address to a house eight miles away?
Answer: It happens only when we share location without letting GPS find our exact location, generally before sending location you are supposed to wait until the location is clearly visible to you and its exactly where you're sitting.
You can share your location or where places are located with any of your conversations.
To do so-
On your Android device, open a new or existing Hangout.
Tap Location Insert location.
Type in a location or address: In the top right corner of the map, tap Search .
Find your current location: In the bottom right corner of the map, tap Location Insert location.
Tap Select this location. The location will send immediately.

google hangouts gives wrong location


While my elsevier in press article shows up on the journal website, it has not appeared in Google Scholar after a week

Question: While my Elsevier in-press article shows up on the journal website, it has not yet appeared in Google scholar after a week. Is this normal and part of the process? If not, what's wrong with it?
Comment: I'm curious - is your paper there by now? Facing a similar problem
Comment: @AmirSagiv Hi Amir. Congratulations on your new paper. Yeah. it appeared on Google Scholar after a short time, but I can't recall how much time it took. Anyway, I think you should be patient. Meanwhile, you can share your new publication on social networks to get more attention. It works a lot.
Comment: Yes it can take some time. Don't worry - it will show up soon.
Comment: My advisor recalled of a time that to submit a paper you had to type it and send by letter. It would take months to get a response and the reviews, and after all the troubles and if you were lucky you would get a printed journal with your paper. They considered it a jump in technology when the department installed a fax machine! Leap forward, now we complain because an automatic online list, that crawls through hundreds of publishers and thousands of papers didn't list our paper after 1 week of acceptance.
Answer: Google Scholar updates on its own unpredictable schedule, based on whatever sort of web-crawling and internal processing schedules Google happens to be running with it.  Sometimes I find that it updates almost immediately, other times not for more than a month.
In short: don't worry about it.  If it's on the website of a reputable publisher, then it will show up sooner or later, and usually within just a couple weeks of publishing.
Answer: Have patience! Google scholar will find it. Give it some time!
Answer: I recently had that issue with a paper and decided to add it manually. When I hit the "Add" button (which appears at the top of your publication list if you are logged in and viewing your own profile), I found that the paper was already in one of the groups under "Select groups of articles that you have authored from the list below," it just hadn't actually been added to my profile. I selected it and it was added with no further hassles.
On another occasion, I did add the article manually. Months later, it was also added automatically by Google Scholar, and I was able to merge the two versions.


Kaarite rebuttal of the new testament

Question: A while ago I was pointed to a Kaarite rebuttal of the New testament from a few centuries ago. I found it online with an interactive chapter by chapter format. Now I can't remember the name or find it by searches. Is anyone familiar with this piece and what is it called?
Answer: I believe that the work you are referring to is Chizuk Emunah, "Faith Strengthened" by Isaac Troki, it is my recollection that this was relatively well received in traditional circles as well.
Comment: What a nice little book!  I just made it through the first half dozen chapters so far...good stuff!

Kaarite rebuttal of the new testament


How should I create a master index of all email correspondence in an office?

Question: My employer requires all email correspondence in the organization to be indexed, for regulatory compliance reasons. Our mail server is not managed by us, and does not have this feature. Each workstation has its own email software. Aside from looking for a new mail provider, how should I index emails in a mostly realtime fashion?
Comment: In addition to archiving your email you should probably also prevent people from circumventing that, both in policy and with active measures such as by blocking webmail providers and the default mail ports. Scandals in the White House such as https://en.wikipedia.org/wiki/Bush_White_House_email_controversy and https://en.wikipedia.org/wiki/Hillary_Clinton_email_controversy can happen in your regulated industry too.
Comment: Does your mailserver support journaling? Our organization recently started using Smarsh for this sort of thing, but requires us to journal over.
Answer: Honestly, indexing data of any sort from multiple places in multiple formats is a recipe for disaster.  You would be better off setting up your own internal email server, switching to a provider that offers indexing features, or adding a  proxy-email server are pretty much your best options.  All three of those suggestions come with their own pros and cons.
If this is legitimately a business requirement... your boss will pay for it.  If you have a small IT department... let someone else to the work for you.  (read as "let office365, google, or other similar company be your email provider")  Trying to do this yourself without a dedicated person for that task will just end up making you look like you don't know what you're doing... and will probably get you fired at some point.
Answer: I think you may be looking for a service or appliance such as the Barracuda Message Archiver. I use the appliance version and it indexes all mail as it is sent / received.
Comment: ...if the original-poster was using office365... which does do indexing... he wouldn't be here.  So, no... barracuda essentials for office 365 is a not really a well-though-out suggestion.
Comment: Assuming that your email provider will work with you on getting it setup.
Comment: Barracuda Networks also offers Barracuda Essentials for Office 365 which includes Email Security Service and Message Archiver. The Barracuda Essentials for Office 365 products are cloud based so you don't need to worry about installing an appliance. You log into the cloud and configure the message archiver for your domain. You will need access to your zone file but it is straightforward.
Answer: The simplest, rawest way to do it would be to tap your organization's internet gateway, listening for connections to the mail server and perform packet capture on all emails going inbound and out. Store the captured packets in some sort of noSQL db.
There are some open-source project that can do this (Moloch comes to mind) but you might have to get a bit creative if the mail server uses SSL.
Comment: "A bit creative" is an understatement. You need to find a flaw in the underlying algorithm, which, if I recall correctly, has been proven secure. Good luck with that.
Comment: Any haters care to explain the downvotes? We do this successfully in our organization for the same reasons.
Comment: Ah, right. I took for granted the fact that we already MITM all traffic by virtue of an intermediary proxy for which we own the certificates.
Comment: Oh, yeah, if you can install your own trusted CA then it's no problem. The trouble comes when people don't use computers they own


Two-Handed Basket-Hilted Sword Usage?

Question: Is there a method of sword fighting where one uses two handed techniques with a basket-hilted sword?  I've heard that this happened, just not where, when, and what the technique was called.
Answer: Historically speaking, there wouldn't be much overlap between the us of the half-swording technique and the advent of the basket-hilted sword. Half-swording was typically used with a longsword by heavily armored combatants.  The basket-hilt arose once technology had advanced to the point that heavy armor began to fall out of favor. The basket-hilt itself being a design to protect the unguantleted hand. Against the lightly armored soldiers of the day a basket-hilted blade would not require a technique like half-swording, but there may have been the odd exception (perhaps some twit who refused to retire his Maximillian-style fluted plate).
Comment: As you say, it'd have been a well established technique with longswords long before the time basket hilts became common. Breastplates weren't uncommon with mounted troops in particular, right up till the 19th century.If you're up close in a press, or just any time you needed better leverage.
Comment: Zen, I agree with you.  My sense of half swording is that it has the most utility in the steel gauntlet era, and basket hilted swords seem to arise with the transition to leather gloves.  Even with swords only sharp at the end, I wouldn't want to expose my hand like that out in front of the guard without a steel gauntlet.
Comment: The one legitimate use I see for half-swording with a basket hilt broadsword (arming sword) would be to penetrate the breastplate of foe lying prone or supine on the ground.
Answer: Half swording.
https://en.wikipedia.org/wiki/Half-sword
There is no space in a basket hilt to use two hands, so the second hand would be on the blade. It became more common with all swords as armour improved.
Answer:
There is no way to wield a proper basket hilt sword two-handed.

This is because the enclosure of the basket shape is specifically designed to protect the sword hand by covering as much of the area around the and as possible.
When wielding two-handed, such as with a longsword, the forearms come in from different angles.  The most coverage you could get would be 180 degrees to the front, if that, and it would still limit a range of potential techniques.
The only thing I've seen proposed is the two-handed Swiss saber,but I wouldn't categorize that limited hand guard as a basket hilt.
The fact that some Swiss sabers have such guards reinforces the vulnerability of the hands in combat with long blades, where the hands/wrists are usually the most accessible target at range.
The introduction of some form of hand protection may relate to transition from steel gauntlets to leather gloves around that general time period, but the design doesn't seem to have caught on, and the use of the Swiss saber was probably specialized.
The lack of steel gauntlets in the basket-hilt era would make half-swording too risky, and there's not much reason to do it with a single-handed sword.
See also: Are there any historical two-handed basket-hilt swords?

Two-Handed Basket-Hilted Sword Usage?


How did Sauron communicate through the palantír?

Question: Did he possess one of the Palantíri at Barad-dûr? Or could he just "tap into" Palantír conversations at his will?
Comment: He had Palantir WiFi
Answer: Yes, Sauron possessed one of the Palantíri. There was originally a stone placed by the Dunedain at Minas Ithil, which Sauron captured and turned into Minas Morgul (the big fortress the Nazgûl that Frodo &c go past in their way to Mordor). Sauron would have taken that stone along with the fortress.
However, Sauron did have more "control" over the stone than others; the stones were not just mechanical devices. They were "aware" of their user, and in particular, that person's authority and ability to use the stone. Sauron was apparently "better" at it than Saruman or Denethor, which allowed him to exert some influence over them and what they saw in the stones. That's what eventually drove Denethor insane, and turned Saruman to Sauron's side.
Aragorn, on the other hand, was the rightful heir to the stone at Minas Tirith, so he was able to influence Sauron into coming out to meet him.
Comment: Tolkien does say that Denethor had as much right to use the palantir in Minas Tirith as Aragorn did.
Comment: Saruman wasn't on Saurons side. He intended to betray him.
Comment: @MattGutting that's why Sauron had a harder time corrupting him; all he managed to do was convince Denethor that he was hopeless. Denethor had the right to use it, he just wasn't as strong-minded a personality I guess.
Comment: @CarlSixsmith or is that that what Sauron *wanted* Saruman to think....?
Comment: @MichaelEdenfield I don't think so. Even after Sauron became suspicious of Saruman, he still had the strength of will to use his voice to dominate the Lord of the Nazgul.
Comment: Aragorn was not able to influence Sauron; merely revealing his identity was enough to change Sauron's plans. His status as the rightful owner is what let him retain control over the Stone during his "conversation", and wrest control afterwards to use the stone independently (to discover, for example, the state of affairs at Umbar and the need to capture the fleet).
Comment: Getting Sauron to change his plans is sort of the definition of "influence"...
Answer: Yes he had a Palantir. You had to have another Palantir to communicate with someone else using one. There was only one Stone, which was lost during the Kin-strife, that could eavesdrop on two other Stones in communication. Otherwise with, or without a Stone, he could not eavesdrop on two Stones in communication.
Denethor, like Aragorn, was a rightful user of the Stone. Sauron never, ever dominated Denethor through the Stone as he had with Saruman.

Sauron failed to dominate him and could only influence him by deceits.
  [The Palantiri]


Positive pin on microphone

Question: Hello can anyone tell me what is the positive on this microphone ?
Comment: Does it have a positive and negative?
Comment: The negative one is usually connected to the case.  Is there a track coming off the top pad going to the case?
Comment: @Finbarr so it looks, it was connected to a red and black wires. See last pic I added.
Answer: That's an electret microphone.
It has an internal JFET as shown here within the dotted rectangle marked "capsule":

This JFET is needed because the electret capsule is like a small capacitor and only generates very small movements of an electrical charge when sound is present.
That small signal needs to be amplified using a JFET and the external resistor to V+
The positive connection will be the output of the JFET.
To find that connection use a multimeter, one of the two pads will be connected to the case as well and that will be ground, then the other pin will be the positive.
Often you can see the connection between the pad and the case, I think we cannot see it on yours as there is some black stuff covering it. Maybe if you carefully remove that black stuff above the top connection we might see the track to the case. My guess is that the bottom connection is the positive.
Comment: I used a multimeter and the case it is not directly connected to the terminals. Then I used a diode test and found the info shown in the pics I added.
Comment: I think that the only thing that makes sense is to connect the ground ( negative ) to the black pin. Anyway I like have other opinion. Can I ruin something if the connection is wrong?

Positive pin on microphone


What is the quickest way to kill all sessions from a specified user in Oracle?

Question: What is the quickest way to kill all sessions from a specified user in Oracle?
Answer: You should be able to do it in a PL/SQL loop. Make sure to test it with just logging the parameters before actually calling kill session.
BEGIN
  FOR c IN (
    SELECT s.sid,
           s.serial#
    FROM   v$session s
    WHERE  s.username = 'your_user_name'
  )
  LOOP
    EXECUTE IMMEDIATE 'alter system kill session ''' ||
                      c.sid || ',' || c.serial# || '''';
  END LOOP;
END;

See similar question on asktom.
Answer: Another approach that could run faster overall is to generate orakill commands and execute them in a DOS window:
SELECT 'orakill '||d.name||' '||spid
  FROM v$session s JOIN v$process p ON addr=paddr
                   JOIN v$database d ON (1=1)
WHERE s.username = 'THE_USER';

Orakill does not wait for session transactions to complete, so the kill is very fast.
Whatever your solution turns out to be, be careful!
Answer: One thing to be aware of is that killing a session in Oracle does not necessarily stop the user's session (and associated processes) from consuming resources.  So a runaway query may continue to run away, consuming resources like CPU and I/O and holding locks, until it checks back in with Oracle's process monitor (pmon) process/thread.
Assuming one's running Oracle on a Unix system in "dedicated connection" mode, one can join v$session and v$process on v$session.paddr = v$process.addr to find all the sessions and processes for a given user's connections, and use the UNIX kill commmand with SIGKILL to kill the underlying server processes for the user's sessions.  pmon will then clean up the failed session, rolling back any transactions and releasing any locks.
This is definitely a big-hammer approach when the approach Peter Lang's previously pointed out isn't killing the user's sessions aggressively enough.
Comment: Thanks for the tip :)  The Oracle server we develop on runs on Windows.  I've added a tag to the question.
Answer: alter system checkpoint;
shutdown abort
startup restrict
shutdown immediate

:)
Answer: Here is a very light improvement of Peter Lang's answer that I find easier to use. It is interactive and asks for the username:
PROMPT Entrer the username to kill;
DEFINE username = &1
BEGIN
  FOR c IN (
    SELECT s.sid,
           s.serial#
    FROM   v$session s
    WHERE  s.username = '&&username'
  )
  LOOP
    EXECUTE IMMEDIATE 'alter system kill session ''' ||
                      c.sid || ',' || c.serial# || '''';
  END LOOP;
END;
/


How to get one core of a quad-ARM running without an OS

Question: I'm using a quad-core ARM CPU and I'm wondering if it is possible to get 3 cores running in Linux, and one core running without Linux?
Comment: I'm a little unconvinced that this is a duplicate.  This question has two parts 1) disabling Linux from using one core 2) using one core to do something non-linux related.  The "duplicate" only addresses the first point.  Yaya, if you feel the duplicate flag was inappropriate you maybe need to ask a new question and include some information on what you would like to do with the "non-linux" core.
Comment: You can use `cpuset` to limit the cores that your Linux-based system will use. I have no idea how you would go about scheduling something entirely different on the remaining core, though.
Answer: You can't just take two operating systems and run one on one core and another on another core. ("No OS" is a special case where whatever code you run effectively includes its own OS merged into the application code.) It's possible to run multiple OSes that way, but they need to be aware of each other and to be written carefully to avoid treading on each other.
Even if you assign one OS to one core and one OS to another core, a computer is more than the processor. The operating systems will compete for memory and peripherals. It may be possible to tell the Linux kernel to keep entirely off one core (and I'm not sure if that's possible: it's not enough to tell it not to schedule any process there, which is easy, you also need to ensure that the kernel won't try to make that core receive any interrupt), but that's only the most obvious problem. If you want to use that core that Linux stays away from, you need to ensure that Linux won't power it down as part of its power management mechanism.
And then there's memory. It's easy to tell Linux to stay off some region of physical memory. But there's only one MMU for all the cores, and Linux needs it. To make Linux cohabit with another operating system, you'd need to make significant changes to its MMU management code so that it allows the other operating system to own part of the MMU data, and the two OSes need to agree on how they use the MMU. It's technically possible to have an OS run without the MMU, but at least with arm CPUs no MMU means not only no virtual memory (obviously) but also no cache, which is extremely slow.
And then there's peripherals. If you run multiple operating systems, practically speaking, each peripheral has to be owned by a single OS, and the other one must stay off. It may even be impossible for the two OSes to use the same bus conjointly, so all the peripherals on the same bus would have to be owned by the same OS.
If you want to run multiple operating systems, cores aren't how to split them. You need to virtualize all these shared resources — physical memory, virtual memory, peripherals, and you might as well virtualize the CPU itself. This is done with virtual machines: each operating system runs in one virtual machine, with access to a virtual CPU, a virtual MMU, virtual interrupts, etc., and there's one operating system that is the host of all these virtual machines and has access to the actual hardware. When the host is dedicates to running VMs and nothing else, it's called a hypervisor.


/etc/rc.d vs /etc/init.d

Question: Is ubuntu's /etc/init.d directory exactly equivalent (functionally) to what I presume to be the more standard /etc/rc.d/ (at least on arch)? Is there any particular reason canonical used init.d instead of rc.d for startup scripts?
Comment: actually arch linux is the only distro that uses `/etc/rc.d` that I've seen... I suspect it might be used in bsd.
Comment: it is used in freebsd
Answer: Ubuntu uses /etc/init.d to store SysVinit scripts because Ubuntu is based on Debian and that's what Debian uses. Red Hat uses /etc/rc.d/init.d. I forget what Slackware uses. There just isn't a standard location.
Ubuntu briefly switched from SysVinit to Upstart, but has now turned to using systemd.
Comment: Ubuntu switched from Upstart to systemd since 15.04.
Comment: Sorry, but /etc/init.d is the standard, as part of the SVR4 standard that Linux start scripts copied.
Comment: Upstart's website claims Ubuntu has been using it since version 6.10
Comment: @badp: Though 6.10, still used SysV-style init scripts in `/etc/init.d`. The transition to `/etc/init/*.conf` started later (8.04 was still all SysV-style, 10.04 was already transitioning).
Answer: /etc/init.d was the old historical location for SVR4.  I forgot why redhat added the /etc/rc.d/ level.  I think to isolate things onto rc.d, but then needed to add a bunch of symlinks anyway for backwards compatibility.  So there is /etc/init.d in redhat, just it symlinks elsewhere.
So the standard location is /etc/init.d, though it may be a symlink not a real directory.
There were some really old Linux distros that copied BSD with /etc/rc.local but pretty much no one uses that anymore.
Answer: Slackware still uses /etc/rc.d
FreeBSD uses /etc/rc.d and /usr/local/etc/rc.d
Answer: Historically, the /etc/rc.d directory tree denotes an Init system which follows the 4.4 BSD tradition of system initialization, which is usually called the rc init system. All the modern (Free/Open/Net)BSD system and Slackware Linux follow this tradition.
The /etc/init.d directory tree denotes the System V (SysV) init system which follows the AT&T UNIX, SunOS, Solaris tradition of system initialization. This is commonly called the SysV Init system. Debian proper still follows this tradition in the Wheezy series, but plans to use SystemD in the Jessie series. Historically, RedHat and derivatives have used SysV Init, but don't anymore.
Also, over time, features of both init schemes have been adopted by distributions.
Comment: And then there is AIX with "/etc/rc.d/init.d/". A little bit of column A and a little bit of column B.
Answer: Actually, at least in CentOS 6.8 Santiago, /etc/init.d is just a softlink to /etc/rc.d.
Comment: That's exactly what I meant, haha. Sorry about the wrong spelling, I edited my reply now.
Comment: Why do people downvote without giving an explanation? The statement unless intentionally irrelevant can still have value or meaning to some novice reader. Explain when you downvote. I +1 to undo the effect of -1
Answer: PuppyLinux has both /etc/rc.d and /etc/init.d, neither being a symlink.  What is a symlink is /etc/rc.d/init.d, which links up a level to /etc/init.d  (I'm looking at a Slackware-based Puppy-- there are also Ubuntu-based and other flavors.)  There's a README.txt in each, explaining their approach.
Answer: Ok so, /etc/init.d is a place where you can quickly deploy an init script. The second step towards activating this script is to run a chkconfig command on it. Say you run chkconfig --add <yourscript>, symbolic links will be created between /etc/init.d/<yourscript> and /etc/rc.d/rcX.d/S50

/etc/rc.d vs /etc/init.d


What did male motorcyclists wear in 1930s England?

Question: What did male motorcyclists wear in 1930s England? I'm assuming the outfits from Watch This Club Ride Vintage 1930s Motorcycles Across France are probably pretty accurate, as well as the top image results for google search. But I wanted to see if anyone has any better sources of information on this topic. Also, I would greatly appreciate it if anyone could put names to the specific articles of clothing, in addition to pictures, as I'm attempting to create a costume.
Comment: The question was phrased as speculation, which generally will earn a question here close votes. However, there's no reason it needed to be, as we know such people existed, so I rephrased it for you.
Answer: This is very interesting, yet very difficult to find much information. You will likely have to combine multiple sources to find your answer.
I like the 2 sources you already have, and pandomoto.com is another one.
From skull caps to leather padding, the military had a lot to do with the style of motorcyclist fashion. I hope this helps!


L LED on Arduino is constantly on and com is not detected

Question: When I connect the Arduino to the computer, the L LED is constantly on and com is not detected. However, when I press the reset button, the L LED starts blinking for about 10 seconds and com appears. But then he leaves.
Comment: What happens if you upload the Blink example in the moment when the com port appears?
Answer: Hold the Reset button down with one hand and start uploading the sketch (like, an empty sketch or the Blink sketch) with the other. Once you see "uploading" release the Reset button.


Starcraft 2: What's the easiest order to do the missions on brutal difficulty?

Question: Finished the first 3, no sweat.. now I've reached the first fork. Looking for some advice on which path to take? Trying to get all the brutal achievements.
Comment: I finished the campaign on easiest, now I can launch any mission at any time on any difficulty. So, not sure it actually matters...
Comment: I didn't realize there were **brutal** achievements. I thought achievements were only awarded on normal and hard.
Comment: @ahsteele: You get achievements just for completing the missions on brutal... @lilbyrdie: That just sucks the fun out of the game, no? Casual is a joke... and normal is pretty darn easy too. Shoulda played hard first time through ;)
Comment: I was wondering if that's what you were talking about. I am working my way through on Brutal on wanted to make sure I hadn't missed anything.
Comment: You get completion achievements on each difficulty, from what I can tell. There are challenge achievements on harder difficulties, though.

@Mark: I didn't find it sucked the fun out. For one, I only played the first Starcraft around 1998-99 and never played the expansions. For two, I was able to get through story quite quickly. It's a great story, too, and I hope they can keep it up through the next two iterations. I'm also finding that the solo challenges are more rewarding for achievements.
Answer: Well, the most obvious path would be to do Smash and Grab, and then do The Dig (Xil) as soon as it appears, because that opens up the Zeratul missions, which will allow you to fill up your Zerg and Protoss research points.
Comment: Zeratul missions are key to do as soon as you get them. So yeah, as soon as you get them, do them all in a row to get lots of research points.
Answer: For most missions, the order doesn't matter, but there are a few key units that it pays to get as soon as possible.
Vikings are useful in several missions, so I think it pays to finish the colonist storyline as soon as you can. In particular, they can be used to knock out Protoss air in "Welcome to the Jungle" (they're way better than goliaths). They're also useful for getting the research in "The Dig".
Battlecruisers can also get help get through some of the tougher missions like "Engine of Destruction", so complete "Maw of the Void" as soon as it's available.
The Zeratul missions don't benefit from any units or upgrades obtained in previous missions, so complete them as soon as possible to get the research.
Comment: If you have a bunch of Vikings, you can get them within visual range of the cannons, then hit them with the laser drill. Vikings are also good for repelling those annoying drops (along with lots of upgraded turrets).
Comment: How are they useful for getting research in the dig? The temple things are right next to where you start, and they're guarded by cannons, no?
Answer: I personally found this very very helpful.
From TeamLiquid:
<code>Mar Sara 1: Liberation Day -marines
Mar Sara 2: The Outlaws -medics
Mar Sara 3: Zero Hour -bunkers/turrets
Artifact 1: Smash and Grab 4protoss(4) -maurader
Colonist 1: The Evacuation 3zerg(3) -firebats
-
Covert 1: The Devil's Playground 3zerg(6) -reapers
Rebellion 1: The Great Train Robbery 3zerg(9) -diamondbacks
Rebellion 2: Cutthroat 3protoss(7) -vultures
Artifact 2: The Dig 3protoss(10) -S.Tanks
Prophecy 1: Whispers of Doom 3Zerg(12), 3protoss(13)
-
Prophecy 2: A Sinister Turn 3Zerg(15) 3protoss(16)
Prophecy 3: Echoes of the Future 4Zerg(19), 2protoss(18)
*Prophecy 4: In Utter Darkness 3 Zerg, 3 Protoss
Artifact 3: The Moebius Factor 3zerg(22) -Medivac
Colonist 3b: Haven's Fall 3protoss(21) -Viking
Artifact 4: Supernova 4protoss(25) Banshee
-
Artifact 5: Maw of the Void 4protoss -Battlecruiser
*Colonist 2: Outbreak 2zerg(24) -Hellion
*Covert 2: Welcome to the Jungle 3protoss - Goliath
*Covert 3b: Ghost of a Chance/Covert 3a: Breakout
*Rebellion 3: Engine of Destruction 3zerg - Wraith
*Rebellion 4: Media Blitz - Thor
*Rebellion 5: Piercing the Shroud 3 Zerg, 4 Protoss
-
Final 1: Gates of Hell
Final 2a: Belly of the Beast /Final 2b: Shatter the Sky
Final 3: All-In

*=option if not on a speed run. also note that if you save Haven, you have
all research for zerg. i thought the 40,000 was more worth it since i never
use psi emitter, and if its a speed run you'll probably do nydus all-in.

Prioity Purchases: bunkers, comm centers, SCV repair, stim, medic heal,
S.Tank, Banshee, merc tanks, merc banshee, merc vikings,
merc battlecruiser, turrets, Viking, marauder, firebat. (in that order)
</code>
Answer: The easiest way to get all the brutal achievements is to cheat: do the whole thing on hard/normal, and get the best stuff, then, when you've completed it, go back using the archive and replay the missions on brutal.
You can finish them without having to complete the secondary objectives, and still have all the best gear. This makes the campaign much easier: trying to complete the secondaries on Brutal is a nightmare. Mind you, if you realize you made a poor decision the first time you went through, that's too bad.
I played the whole thing through on hard, getting all the achievements for every mission, so it was easy, once I finished, to just go back and replay every mission on brutal difficulty. Sadly, I often found it easier to beat it on brutal, than it was to get some of the achievements on hard.
Comment: I've already played through and gotten every achievement on hard... but the added units/upgrades don't "backdate" so... it doesn't really help any. Thus I've restarted the campaign so I can pick the optimal upgrades.
Comment: @mark: They don't "backdate" but they do stay at the level where they were when you first played the mission in the campaign. So you can play an archive mission, and ignore the zerg/protoss points, and then play the *next* archive mission, and, if you got them in the original play-through, you'll have them in the next mission.
Comment: I know...but I didn't choose all that good the first time through.


Phantom contact record

Question: I have a view that displays civiCRM contact records according to Contact Type. The displays needs to change every Fall, and the way we do this is by changing the contact type (but keeping the record).  There is a particular contact record, however, that displays on the view but is missing from our civicrm records. I have looked under his name, email, and contact id, but nothing comes up. This should not be possible: the view displays the contact record's name, bio, university, and image. So how is this person's record displaying if I cannot find him in a search?
Comment: Jon G of Megaphone Tech's answer was correct: "Most likely, the contact is deleted, but your view isn't filtering out deleted users. You may want to check that in your view. You can search for deleted contacts from Search menu » Advanced Search by checking the "Search in Trash" checkbox. "
Answer: Most likely, the contact is deleted, but your view isn't filtering out deleted users.  You may want to check that in your view.
You can search for deleted contacts from Search menu » Advanced Search by checking the "Search in Trash" checkbox.

Phantom contact record


how to connect SQL server from oracle in SQL developer

Question: I have two connections in SQL developer that one of them is SQL server (A) and the other one is oracle (B).
how can I make a database link between this two connections from (B) to (A) to select connection A data from connection B?
Comment: It really has nothing to do with 'connections', as defined in SQL Dev.  That is just a construct within SQL Dev to define how it connects to a particular database.  SQL Dev is just a client to any one database. While you can have SQL Dev connections concurrently open to multiple databases, those connections have no more to do with each other than two separate invocations of sqlplus, each connected to a different db.  If you want to access an oracle db from an MSSQL db, you create a 'shared server' in the MSSQL.  If you want to go the other way, create a DB Link in the oracle DB.
Comment: HIt the space limit in my previous response.  In order to better understand the concepts, you might find this blog article ineresting: http://edstevensdba.com/oracle-heterogeneous-communication/oracle-transparent-gateway/.   And remember, this is not a SQL Developer question.
Comment: @EdStevens - hitting your limit on a comment is a good indication that you are writing an `Answer`, not a `Comment`.
Answer: The last time I looked (and that's quite a number of years ago), you needed Oracle Gateway to establish such a link.
Just checked, the product is still around: Oracle Database Gateway for SQL Server.


Mechanics of questions being somehow "featured"

Question: I am trying to understand the votes I am getting on an answer of mine.
For some days now, I haven't gotten much votes on this answer, but in the last few hours, I got 13 votes out of nowhere.
I am trying to understand the mechanics behind this. Where is this question featured/displayed/whatever that makes people click on it and vote on it and the answers, although it is nearly a week old now? The question doesn't have an open bounty, so that can't be the reason...
And why does it happen in such "surges"?
Comment: I think you are making fun of me, but anyway: Sorry, I don't understand :)
Comment: Must be because it was C# and C# is where the golden showers happen
Answer: The "Active" tab is the default view for stackoverflow.com/questions, and as Neal says one of the answers was edited:

Questions start out at the top of the 'Active' tab when they are first posted. A question will be "bumped" back to the top of the 'Active' tab whenever it receives a new answer, a tag is added or removed, or one of the questions/answers is edited.

From How is the Hot/Active question algorithm implemented?
So when the question became active, lots of people saw it in the Active tab, and some of those who viewed it voted on your answer.
Comment: Thanks for your answer. Please see my comment to Neal's answer...
Comment: Are comments also responsible for bumping a question back up?
Comment: @Daniel Hmm, that's odd. I wonder if it was linked/tweeted somewhere, or perhaps it was on the logged-out Interesting page.
Answer: This is because the answer right under yours was edited 21 Hours ago so that could be it
So when users saw that that question was bumped 21 hours ago, they saw your answer and voted it up as well.
Comment: It could also depend on the question being part of this week's newsletter...
Comment: @Daniel -- also it could do with the time of day. It could be that type of question has a niche of people who go on SO at a certain time in the day and that happened to be the time that you got the upvotes.
Comment: Hm... I don't know. The votes started rolling in only 3.5 hours ago. And since then I got a vote every few minutes... That doesn't look like it is the "Active" tab.
Comment: @Bo Persson: Thanks. That sounds reasonable, too.


How much RF-interference does a typical desktop computer produce? How much does a metal case without windows reduce it?

Question: It's fairly common now to see desktop computers in cases with large windows cut in the sides. I've always been under the impression that if unshielded, computer equipment will produce a lot of radio frequency interference. Given the ubiquity of cell phones/wireless routers, etc, I can only assume it's not radiating all that much. What I'm interested in is how much power, over the whole RF spectrum, a shielded and unshielded computer system could produce. My desktop has a 900 Watt power supply. If it radiated even 1% of that power, there'd be a huge amount of radio interference in my apartment, wouldn't there?
Comment: Dunno how much actual radiation gets emitted, but I did some calculations a while back for shielding effectiveness and even 0.01" of stainless steel has >100dB attenuation (1Hz-1MHz, increasing attenuation with frequency). Assuming that all 900W is emitted as EMI in this frequency range, there's 90nW of EMI leaving a well shielded case. Of course PC's run at much higher frequency, where hole sizes will decrease the effectiveness of the shielding because the holes will start looking like holes to the EMI.
Comment: Given that everything shipped in the EU has to meet strict RF emissions limits, I'm fairly sure that it doesn't emit a lot.
Comment: @helloworld922 Can you walk me through those calculations?
Comment: Any RF emissions that are emitted (which have to be very low, or the PC's wouldn't have passed FCC/CE testing) have little to do with how big your power supply is.  The emissions are coming from the CPU chip and other chips which are switching very fast.
Answer: Well I don't really know.  But two ideas to measure (or compare) it.  First if you have a 'scope then clip a bit of bus wire on the end of your x10 scope probe and move it around... take off the case, put it near the over head fluorescent lights.  If you don't have a 'scope then you can do some with an AM radio.  Tune to a blank spot and try and hear the noise as you move it around.  (The radio idea comes from here.)
Answer: If you look on the chassis you should see the compliance rating class. Class a or b for instance. This will lead you in the right direction to see what the maximum allowed emissions would be for that device class. Most reputable manufacturers do not publish exactly how close to the class limit the product is as that would give  the competition too much info.


Plug sdramps module and Anet A8 LCD together into RAMPS smart adapter

Question: I want to upgrade my Anet A8's motherboard (the stock one is broken anyway, see: Anet A8 reading 739°C from the extruder thermistor!) to the RAMPS 1.4, without having to get a new LCD/microSD module. I am thinking of getting both a smart adapter and sdramps, then maybe plug the sdramps and the stock Anet A8 LCD into the smart adapter, but I am not sure whether the sdramps module has a different pinout than the RAMPS smart controller, which is what the smart adapter is made for.
Can someone confirm whether they have the same pinouts or not, or give me some alternatives to my idea?
Comment: The link above gives you information on the pin layout which you can compare to the layout on the RAMPS. You know there is a 1.6 version which has improvements on MOSFET cooling and more copper in the traces?
Comment: I've seen the other way around where someone connects a rep rap LCD to the board: https://www.thingiverse.com/thing:2103748
Comment: @0scar it is easy the other way around, but I want to keep the stock LCD in order to save some money.
Comment: @0scar 1.6 has SMD fuses, which are much harder to replace than removable fuses, or even through-hole soldered ones.
Answer: The Anet A8 uses a simple LCD with 5 buttons, the problem is that the buttons do not use digital pin signals, instead analog pins are used. Based on the pressed button, with corresponding resistance the firmware knows which button is pressed. The RAMPS smart adapter uses digital pins, so the Anet LCD is not compatible with the smart adapter, you may wan't to opt for a cheap Chinese 12864 LCD smart controller, they are about $8, they are compatible.

The topic Connecting (Anet A8) 2004 display to MKS GEN L shows you to hook up the Anet A8 LCD to a RAMPS board. You do not use the smart adapter, instead you use AUX2. You only have to change 2 wires (interchange them on AUX2) and you will be able to use the display. The reason you cannot use the smart adapter is that the 5 button display requires analog pins, which are not available on the smart adapter, but are available on the AUX2 header.