Find the minimal lexographical string formed by merging two strings

Question: Suppose we are given two strings s1 and s2(both lowercase). We have two find the minimal lexographic string that can be formed by merging two strings.
At the beginning , it looks prettty simple as merge of the mergesort algorithm. But let us see what can go wrong.
s1: zyy
s2: zy
Now if we perform merge on these two we must decide which z to pick as they are equal, clearly if we pick z of s2 first then the string formed will be:
zyzyy
If we pick z of s1 first, the string formed will be:
zyyzy which is correct.
As we can see the merge of mergesort can lead to wrong answer.
Here's another example:
s1:zyy
s2:zyb
Now the correct answer will be zybzyy which will be got only if pick z of s2 first.
There are plenty of other cases in which the simple merge will fail. My question is Is there any standard algorithm out there used to perform merge for such output.
Comment: how do you exactly you merge the two strings? Each step you pop a character from the beginning of one of them?
Comment: @svs start from left of both strings and pick the smaller character.
Comment: The problem is thinking that it's simply the merge operation of merge sort. Merge sort works on the assumption that your sublists are already sorted. Your string's are not sorted, hence the problem.
Comment: @dhke We cannot change the two input strings, hence we cannot sort them.
Comment: @SumeetSingh Yeah, but that leaves defining the "merge" operating up to you, as you violate the precondition (sublists are sorted) for the mergesort merge. In your case the solution is probably: If both candidates are equal, pull both. But again: You need to define what you want as a result.
Comment: @dhke Resutl should be minimal lexographic string.
Comment: @SumeetSingh And what exactly is that? What operations are allowed for the "merge"? As is, I consider this underspecified, because I need to know how to merge the strings to determine what the lexicographically minimum possible result would be. But exactly the merge operation is open for discussion from the question.
Comment: @dhke It means the one that comes at least  position in a dictionary. The only operation that is allowed is u have to pick one char at a time from the left of string, of course main problem comes when both chars are equal which i showed.
Comment: @SumeetSingh Shouldn't the expected result then be `zzyyy` (or `zzyyby`, respectively), because you are otherwise violating the merge rule? Or returning back to my initial comment: What rules are to apply?
Comment: @Sumeet, if you are doing it char by char how is your 2nd example zybzyy correct?
Answer: You could use dynamic programming. In f[x][y] store the  minimal lexicographical string such that you've taken x charecters from the first string s1 and y characters from the second s2. You can calculate f in bottom-top manner using the update:
f[x][y] = min(f[x-1][y] + s1[x], f[x][y-1] + s2[y]) \\ the '+' here represents
                                                    \\ the concatenation of a
                                                    \\ string and a character

You start with f[0][0] = "" (empty string).
For efficiency you can store the strings in f as references. That is, you can store in f the objects
class StringRef {
    StringRef prev;
    char c;
}

To extract what string you have at certain f[x][y] you just follow the references. To udapate you point back to either f[x-1][y] or f[x][y-1] depending on what your update step says.
Comment: Appreciate the answer but length of s1 and s2 can go up 10^5, Hence We require a different approach.
Answer: It seems that the solution can be almost the same as you described (the "mergesort"-like approach), except that with special handling of equality. So long as the first characters of both strings are equal, you look ahead at the second character, 3rd, etc. If the end is reached for some string, consider the first character of the other string as the next character in the string for which the end is reached, etc. for the 2nd character, etc. If the ends for both strings are reached, then it doesn't matter from which string to take the first character. Note that this algorithm is O(N) because after a look-ahead on equal prefixes you know the whole look-ahead sequence (i.e. string prefix) to include, not just one first character.
EDIT: you look ahead so long as the current i-th characters from both strings are equal and alphabetically not larger than the first character in the current prefix.
Comment: Why downvoting? Any counter-example?


What kinds of conflict of interest concerns are there when interviewing with a vendor of my current employer

Question: I am being recruited by a vendor who sells equipment and software to my current employer. My recruitment would not put me in a position where I would be selling or working on projects for the company I work for now. Assuming I act ethically, adhere to my confidentiality agreement, protect all trade secret information obtained in my current position, and I am not under any explicit agreements to the contrary - is it ok for me to pursue this position?
Comment: just an anecdotal reference, something similar happened in the company, on of our SaaS providers hired one of our directors, and magically 3 weeks later our company decided not to renew the contract, ofc tehy didnt say it was because of that but you know.. rumour has it...
Comment: That is one of the concerns I have. I'm fairly low on the totem pole so I'm not sure how much this particular concern factors into my situation but you make a good point to the general situation.
Comment: A local hospital hired away a few of our key people... interestingly, in a completely unrelated side note, as of 2014 that group will no longer be covered by our health plan.
Comment: Your employer doesn't own you beyond what you have explicitly agreed to (in contracts) or as defined by law (like willful slander or intentional damage through action or dissemination of information). They may hate you for leaving or for joining a vendor or for whatever reason, but there is no law against that and you can't always have everyone liking you ;)
Answer: It's not entirely clear what your specific concern is, but yes, assuming you "act ethically in keeping any confidential and trade secret information" confidential/secret, then there should be no issues with you pursuing the new position.
Note that this doesn't mean that your employer will be happy if/when they eventually find out about it, but in most cases you will have just as much a right to pursue a position with the vendor as you would with any other company.
It may be the case that your company and the vendor company have an agreement to not poach each other's staff, but if this is the case then it's the responsibility of the vendor to abide by the terms of the agreement.  So even if such an agreement exists between your company and the vendor, it's not something that you personally need to worry about.  And the fact that it sounds like the vendor approached you strongly implies that no such agreement exists.  Either that, or their recruitment person is about to get themselves into some trouble.
Anyways, yes, it's okay for you to pursue the position.  If you're concerned about the possibility of unintentionally letting any sensitive information slip as part of the interview process, then you might want to insist upon signing a mutual NDA with the recruiter.  That way, even if you fail to act ethically (either intentionally or otherwise), any sensitive information you disclose cannot be used or reproduced by the vendor.  If you want to ensure you're doing right by your current employer, a mutual NDA is an easy way to do so.
Answer: It sounds as if there are no legal concerns on your side and since the company knows who your current employer is, they would know in pursuing you if there were any legal concerns on their side (Recruiting firms for instance often have written agreements not to poach from their customers). So you are probably safe to pursue it. I will remind you that you are under no obligation to tell them where your new position is when you leave.
Comment: there might not be any legal concern, however I don't he is really worried about legal stuff, also I think that if the hides and the company finds out later they might think is "shady"
Answer: Sounds like legally and ethically you are covered.  Be aware if you move that the danger zones are often the grey areas - answering questions from former collegues, networking to connect people in the vendor company with people in your former (the customer) company who normally wouldn't be connected, or inadverently using inside knowledge in subtle ways that aren't a direct disclosure.
One thing that may be worth researching is whether your current employer has been litigious with regard to any non-compete agreement you may have signed.  There are cases where employees have been sued for intellectual property or non-compete issues that are fairly nebulous and dubious.  It's not a situation that would be likely to win a court case, but rack up enough legal fees, and you'll be in bad shape whether you win or loose and you can't necessarily count on your new employer to back you up.  It's worth nosing around to see if your current company has a reputation for pulling such tricks.
Answer: If there were actual issues regarding this, there would or could be a severe negative impact with the new employer, the vendor. I'm not talking legal agreements, though quite often those are included in their contracts. I'm talking about the desire not to anger or alienate a paying customer and lose their business over hiring away an employee.
So.... the vendor is pursuing you for a position. I can't believe that they would be oblivious to issues, if there were any, and, certainly, they wouldn't be so foolish as to recruit you for a position that would be impossible for you to function in, if there would be bad blood over the hiring.
If it's okay with the vendor, I think it's safe to assume it's okay for you to pursue, because all the potential negative ramifications, some of them quite substantial, would fall on them, primarily.


Is there any mention of a condition that includes "mixing means and ends"

Question:
Ends: what we aim to do.
Means: the things we use and the actions we take to create our ends.

Is there any mention of a condition that includes the subject treating means as ends or the opposite or both?
Comment: In a pathogenic way?
Comment: To the extent humans are pathological. See also https://en.m.wikipedia.org/wiki/Consequentialism
Comment: I don't know what this looks like "treating means as ends or the opposite" - I know what prioritizing means over ends or the opposite looks like, but not what treating them looks like.  Can you provide some examples?
Comment: Like @ArnonWeinberg, I am finding it hard to grasp exactly what you are trying to describe. Maybe a combination of Michael's answer and my comment to it answers the question, maybe you are looking for something different. I'm just not sure. Are you able to elaborate within your question a little more on what you are after?
Comment: Just "being human"?
Answer: The matter in question is whether there are behavioural conditions which confuse instrumental value and intrinsic value. In common terms, instrumental value references means to an end, or the tools and steps needed to arrive at the naturally desired or intrinsically good object or state of affairs. Intrinsic value, in contrast, refers to an end in itself, or something which satisfies biological desire or otherwise some divine good. In psychology, the corresponding terms are intrinsic and extrinsic motivation.
In modern complex society, many common goals are instrumental. Some are moreover very general, such as money, education, and social status. With how popular these goals are, the prevailing culture may not recognise their pursuit as inherently pathological, even when done in excess. Less general, more specific obsessions like collecting cars or refining skills that may never be used are also usually accepted as merely people being people. Technically any case where an intermediate goal is pursued without desire for its end goal may fall into this category, as for example having sex without desire to reproduce. But in practice, and indeed in this example, there can still be other benefits, such as physical and mental exercise. Yet arguably, chasing some instrument on the grounds of a highly unrealistic fantasy scenario may be inherently maladaptive.
With that said, there are some notable obsessions which may be more likely to be questioned by society. Obviously personal taste comes in, and those with a maladaptive instrumental obsession may be unwilling to reconsider. A particularly noteworthy example is compulsive hoarding, or the unnecessary, often cluttered accumulation of items, sometimes of very low or negative value. Here, the item's instrumental value may be grossly over-assessed; or otherwise the scenario where its accumulation would be net beneficial may be extremely unlikely to occur. A perhaps more common and maybe more accepted example is overeating. Rationally, the inherent value in food consumption is in its sustenance. But because of how the urge manifests, the instrument may be taken as the end in itself.
A fairly common theme seems to be the accumulation of instrumental goods, skills, and tokens beyond their reasonable expectation of utility. The person appears to forget or have trouble assessing their usefulness or likelihood of being needed.
In the case of building skill, a further consideration is the goal orientation behind its pursuit. From Wikipedia:

In general, an individual can be said to be mastery or performance oriented, based on whether one's goal is to develop one's ability or to demonstrate one's ability, respectively. [...] [Goal orientation] refers to how an individual interprets and reacts to tasks, resulting in different patterns of cognition, affect and behavior. [...] Individuals with a mastery orientation seek to develop their competence by acquiring new skills and mastering new situations. [...] Individuals with a performance orientation seek to demonstrate and validate the adequacy of their competence to receive favorable compliments while avoiding negative judgments. [...] A mastery orientation is characterized by the belief that success is the result of effort and use of the appropriate strategies. [...] A performance orientation is characterized by the belief that success is the result of superior ability and of surpassing one's peers.

Hence, a person who obsesses over a skill or other achievement may be doing so mainly for recognition or fame. The point at which such effort becomes pathological may differ from that of the person doing so based on an irrational or unattainable fantasy scenario.
One explanation for some of these phenomena is that certain evolutionary instinctual urges may be unfit or unadjusted to the modern environment. The human obsession with sugary foods is one example. It may be not necessarily that the person is thinking irrationally, but rather that their intrinsic drives are out of alignment with rational instrumental need. Nature may have instilled higher emphasis on the instrument than is suitable for current times.
Another hypothesis is that mental associations may have been formed, perhaps in early life, between some auxiliary or peripheral object and some intrinsically desired end. Especially if that end goal is unattainable, chasing or dabbling in related or associated mental objects may bring temporary relief. This is analogous to scratching around an itch. A common example is maladaptive daydreaming, where excessive time is taken in mental fantasy, often at the expense of other needs. Like in hoarding disorder, irrational or unreflective assessment of scenario likelihood may waste time that could have gone toward needs or opportunities more accessible.
TL;DR: compulsive hoarding; overeating; maladaptive daydreaming.
Comment: With your intro to intrinsic and extrinsic motivations, the lines can be very blurry. An extrinsic motivation for money can also be intrinsic in the sense that becoming financially rich may be the ultimate goal. Obtaining a smaller amount to invest in a larger project makes money both intrinsic and extrinsic in value at the same time.
Comment: Trying to define hoarding in terms of intrinsic/extrinsic motivations can be tricky, too, as reaching the end goal may not be able to be seen by the hoarder. "Comfort eating" can result in overeating due to the fact that the eating is not necessarily providing the desired comfort level....
Comment: @ChrisRogers -- I agree. Ascription of purpose and intent is often rationalisation of otherwise fluid and heuristic instinctual urge. The line between goal and means is particularly unclear when both may bring motivation on their own. The distinction is further blurred by *automaticity,* or unconscious offloading as behaviour patterns become second-nature, possibly obscuring the original intention. Indeed, behaviours can be driven by multiple intrinsic and extrinsic motivation simultaneously.
Answer: One example could be 'misidentification' whereby a person identifies themselves with their biological instincts and thinks their purpose, their end, is to procreate, whereas procreation is a means to self-fulfilment.
More generally, from Kant:

Now, I say this: Man, and in general every reasonable being, exists as
end in itself, and not merely as means, of which such and such a will
can make use as it pleases; in all of his actions, in those which
concern himself as well as in those which concern other reasonable
beings, he should always be considered at the same time as end.


Windows 2012 R2 - L1 cache N/A

Question: I have a number of Windows 2012 R2 servers running as VMs on a XenServer 7.0 host. When I open Task Manager in any VM, it reports the L1 cache to be "N/A". The server is a decent spec, only a year old, a Dell R730. Should I be concerned or is this normal, and if so, why?
Answer: It's because XenServer doesn't pass this information to the VM's. Nothing to worry about.

Windows 2012 R2 - L1 cache N/A


Running ubuntu 12.10 from a USB stick?

Question: Sounds easy but it is not.I downloaded ubuntu 12.10 to a USB stick so I can carry it around and use it on any computer.I try  to running the OS from stick but it just does not work.So what I am doing wrong and what I have to do  to get to work.Search on the Net    for good tutorial but find  none.
Comment: Welcome to Ask Ubuntu. Please edit the question and indicate how you installed the Ubuntu 12.10 on a USB stick. Just copying the iso file to a USB stick won't do. The instructions are at [How to create a USB stick on Windows](http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows)
Comment: Are you sure that your boot flag is working?
Comment: @C.S.Cameron What do you mean by "Remove the side from the case.?" Second question: Regarding your end note "Persistence can be increased by adding a home-rw file or persistent partitions." Is this only for persistent install, or does it have anything to do with the full install too? Thanks. (Sorry, I could not find "comment" option, so posted this as an "answer."
Answer: Use an application like Linux Live USB (Windows) or UNetbootin/Startup Disk creator (Linux).
Just navigate to the .iso and burn it to your usb drive.
Answer: A persistent install as described above is OK for testing Ubuntu but should not be updated, takes a long time to boot, is not secure and is limited to 4GB persistence*.
You can alternately do a Full install to USB:
Following is step by step how to install 12.04 on a 8GB flash drive, it is similar to installing to internal drive:
Turn off and unplug the computer. (See note at bottom)
Remove the side from the case.
Unplug the power cable from the hard drive.
Plug the computer back in.
Insert the flash drive.
Insert the Live CD or Live USB.
Start the computer, the CD/USB should boot.
Select language.
Select install Ubuntu.
Select Download updates while installing and Select Install this third-party software.
Continue
At "Installation type" select "Something else".
Continue
Confirm Device is correct.
Select "New Partition Table"
Click Continue on the drop down.
(Optional partition for use on Windows machine)
Click "Free space" and "Add".
Select "Primary".
Make "New partition size..." about 1000 megabytes.
Location = Beginning.
"Use as:" = "FAT32 file system".
And "Mount point" = /windows.
Select "OK"
Click "free space" and then "Add".
Select "Primary", "New partition size ..." = 4500 to 6000 megabytes, Beginning, Ext4, and Mount point = "/" then OK.
(Optional home partition)
Click "free space" and then "Add".
Select "Primary", "New partition size ..." = 1000 to 4000 megabytes, Beginning, Ext2, and Mount point = "/home" then OK.
(Optional swap space, allows hibernation)
Click "free space" and then "Add".
Select "Primary", "New partition size ..." = remaining space, (1000 to 2000 megabytes, or same size as RAM), Beginning and "Use as" = "swap area" then OK.
(Important)
Confirm "Device for boot loader installation" points to the USB drive. Default should be ok if HDD was unplugged.
Click "Install Now".
Select your location.
Continue.
Select Keyboard layout.
Continue.
Insert your name, username, password, computer name and select if you want to log in automatically or require a password.
Selecting "Encrypt my home folder" is a good option if you are worried about loosing your USB drive.
Select Continue.
Wait until install is complete.
Turn off computer and plug in the HDD.
Stick the side panel back on.
Note:
You may omit disabling the hard drive if after partitioning you choose to install grub to the root of the usb drive you are installing Ubuntu to, (ie sdb not sdb1). Be cautious, many people have overwritten the HDD MBR.
You may do an update-grub later.

Persistence can be increased by adding a home-rw file or persistent partitions.
Answer: After you create Linux live USB, use an Linux live USB (Lili USB creator) or Unetbootin.
Make sure that the USB is the first bootable device in BIOS.

Running ubuntu 12.10 from a USB stick?


Question locking and migration?

Question: Grrr, I had a nice garden related answer ready to go on the ginger question, but it was migrated to a different forum 3 seconds before I hit post. Evidently the system when it saves drafts does not take this into account when allowing migration? Too late now of course, but 15 minutes gone up in smoke.
Answer: Sorry Colin but it was definitely a cooking question.  The original poster even wondered where it should go.
If it is any consolation I didn't have the question open for migration for more than the time it takes to type Seasoned Advice so I guess it's just bad timing.
Sorry!
Comment: No problem Kevin. I considered it to be a garden question from the point of view of moisture content in beans, potatoes, luffa, all similar situations with meaningful lessons to be learned for gardeners. I'm surprised there is no warning pops up for mods when a draft exists, that's all.
Answer: If you happen to find yourself with an answer that's suddenly missing a question, you could write a corresponding question yourself  (hello, Jeopardy!) and make sure that it's on topic for the site. You must have seen something in the original post that prompted you to write an answer.
Admittedly, I am not sure how long the answer will be cached once the question is gone, so the system may thwart that suggestion.

Question locking and migration?


What does 'Snake in my ear" mean?

Question: Some older person was talking about evicting some renters from her property, and she said to me "she had a snake in her ear".
Comment: Probably an allusion to Eve (as in Adam and Eve) and the snake in the Garden of Eden, which snake conned Eve into disobeying God's express command to not eat of the fruit of the Tree of Knowledge of Good and Evil. In other words, the snake in Eve's ear tempted her into original sin and causing the Fall of Man (from God's grace). The lady landlord is talking about some unscrupulous person leading her renter astray. Conning her. Tempting her to sin.
Comment: *Some older person* ... was she a native English speaker? I ask as there is no note of "she had a snake in her ear" as being anything other than literal. It is certainly not an idiom. As such, this will only lead to opinions.
Comment: @DanBron I found a church facebook post that seems to support your theory. https://m.facebook.com/story.php?story_fbid=1618987534832815&id=889833337748242&__tn__=%2As%2As-R I wasn't convinced before but the specific reference in the post to eviction changed my mind. If you make an answer I'll upvote it.
Comment: She was a gossip, perhaps?
Comment: Michael, you left out most of what might have been relevant, unless you're suggesting she literally said *I'm evicting some renters and I have a snake in my ear*. Did she, please?

*She had a snake in her ear* suggests that you left out either how that referred to the tenant's habit of wearing snakey jewellery or how one of them had an *ear-worm*, which is to say a word or phrase which kept popping up in her ear, presumably without real *hearing*…
Answer: This is an allusion to the Biblical event of Eve being persuaded by the devil in the form of a snake to disobey God. A bad actor or perhaps just bad thoughts (as if they came straight from the devil) were at play when she made her decision to evict the renters from her property.
I found some examples of the expression being used as a much closer allusion to the Biblical story, or even with reference to the story itself. From a mass:

Everything was good, but then but then along came the snake whispering sweet deception into her ear: Eve. Hey Eve. It's me hey Did God really say that you can't eat from any of these wonderful trees? No. No, he didn't say that.

The fictional story Devil-cum-Shoeshine Boy Tells a Customer the Genesis of His Current Occupation Is a Bad Bargain with a Savvy Businessman:

No, she Heisman'd me, dazzled by the other snake whispering sweet Apple in her ear. Pretty good deal it turns out; trades damn near two hundred bucks a share now.

The book Secrets in the Attic:

I had my own Garden of Eden at my house. [...] Was there a snake whispering in our ears?
Answer: She may have been referring to an ear cuff
Comment: Well clearly I didn't think that was 'obvious' or I'd not have suggested it. :) What, about the extremely limited context, makes it obvious that it isn't what is meant? An older person discussing, presumably younger, renters that she was evicting may easily make comment about unconventional adornments.
Comment: I... Wasn't expecting that. I think from context it is obvious this is not what was meant.
Comment: @ApplePie The question as to what was obvious was a genuine one and I'd still like to know what it was that three people thought I missed, if you felt able to clarify.
Answer: A Google Books search turns up several recent instances in which "a snake in [one's] ear" seems to function as a metaphor for being susceptible to bad thoughts, bad advice, or a bad attitude toward God.
From Daughter of Sarah, From Adam to Jesus: What Every Wife Should Know (2014):

A wife must be Jesus centred – her beauty comes from focusing on Jesus (beauty coming from the heart/centre/Jesus) and then His beauty will manifest in her. We must not put our trust in our own beauty, but focus on the beauty of Jesus to influence and touch our husbands. This beauty is eternal and will capture your husband. This beauty from Jesus is manifested as a quiet and gentle spirit. So when your husband speaks to you in a disrespectful manner you are given two choices either eat from the tree of knowledge of good and evil or The Tree of Life. You will most probably hear the voice of the snake in your ear pushing you to eat the fruit of the flesh:
Are you going to let him speak to you like that? That i not hoe the Bible prescribes him to treat you. You need to tell him that he is not fulfilling his role as a husband in the eyes of God. Until he decides that he is going to treat you with respect you will also not honour him as your leader.

From Sara Gennusa, Pearls from the Heart (2019):

I will not make agreements with a stranger's voice neither in word nor deed. I will guard my heart and my tongue against such agreements. I will only confess Your words, for out of the heart spring the issues of life. "Keep your heart with all diligence, for out of it spring the issues of life" (Proverbs 4:23). I will not feed the snake in my ear. I will consciously awaken my heart and starve him out with Your word, Jesus, and Your word alone. The trap has been set and I am anticipating sweet freedom.

From R.S. Gunn, A Certain Woman: Accepting Your Call and Meeting the Conditions (2020):

Awesome. [According to my physician] I could have an occasional drink. And I did. Then my occasional drink turned into a fairly often drink. I felt good there. I could have a glass of wine or cold brewski every few days. That wasn't so bad. God wouldn't punish me for that!
I was actively eating the fruit.
I wasn't listening to God; I had a snake in my ear, and I liked what he was saying.

But the serpent said to the woman, You shall not surely die. (Genesis 3:4 AMP)

In all three instances, the snake evidently represents an external,  diabolical source of personal motivation—as the serpent in the Garden of Eden does.
An older but obviously kindred expression replaces snake with serpent. For example, from Edward Bulwer Lytton, The Wife's Tragedy, in Poems (1855):

Gertrude. Yes. I see it all at last— / All in ruins. I can dare / To gaze down oe'r my lost past / From these heights of my despair. / O, when all seem'd grown most drear— / I was weak—I cannot tell— / But the serpent in my ear / Whisper'd, whisper'd—and I fell.

From Brian Edwards, Daddy Was a German Spy (2008):

We walked and Barry [who said that he had been "saved" three years earlier] talked. He was so joyous it made me want to put my finger down my throat. We arrived at the ABC cinema on the Lisburn road. The movie was Picnic, starring Kim Novak and William Holden. I'd seen it the previous Saturday and lust had not slept since. Barry looked at the poster of Novak dancing seductively in the band rotunda.
'Well, brother,' he said, in a presumptuous display of fraternity. 'you'll never be in that den of iniquity again.'
His voice was drowned out by the hissing of the Serpent in my ear: 'Never see Kim Novak again, Brian! Never again!'
I was a lost soul.

From Gerald Wood, A Life of Jesus, by the Good Doctor: Meditations and Reflections on the Gospel of Luke (2017):

"The devil said to him, 'If you are the Son of God, command this stone to become a loaf of bread'" (Luke 4:3, 4).

...
If you look at the temptation that Jesus faced here, it is all so reasonable. Jesus was hungry. Bread is a basic staple of life. What would be wrong to turn a few rocks into bread? God would understand. The most basic of all temptation is not to place our trust in God when it seems we have to turn our back on our most basic responsibilities. God is not calling us to be outwardly religious while inwardly self-serving. It is why we never reach a point beyond temptation. Yes, the lurid and sensational may not be attractive to us, but that does not mean we are ever free from the serpent in our ear asking, "Did God really mean that?"

And from Simon Chesterman, I, Huckleberry (2020):

My hand gripping the wet stone, I climb onto the ledge.I am directly above the clock face: eight minutes past eight, as it always has been, and as it always will be.
"That's right Huck," The voice is a serpent in my ear. ""It will all be over soon. You do know how this ends after all."
Once more, I look down at the courtyard, its cobblestones waiting to embrace me.
...
And then I saw that the true end was indeed the death of the author. An end to sorrow and confusion, to suffering and embarrassment. The serpent in my ear told me to jump and I climbed onto the ledge.
But there was an interruption, another voice, another story to be told.

Conclusions
Of the preceding quotations, only one takes the exact form that the poster asks about: "I had a snake in my ear." But all involve using the phrase "snake in my ear" as a figurative (or supernatural) embodiment of temptation, evil counsel, or justification for sinful behavior. It seems fair to say that for some people, anyway, "having a snake in one's ear" means playing host to an advocate for unrighteous behavior.
Whether the landlady cited in the poster's question was saying that one of the renters she was evicting had fallen under the influence of wicked tendencies is impossible to say from the information provided in the question. But while using the figure of a snake in one's ear to represent such a person is hardly idiomatic or proverbial in English, it does appear in some published works and would certainly be recognizable to many English readers as an allusion to the biblical story of Eve, the serpent, and the tree of the knowledge of good and evil.
Answer: It means that she is a fake friend. She listens and then backstabs with the info given.
It's a form of speech, like "you hit the nail on the head" for example.
It can also mean she is untrustworthy.
Comment: I think you need to clarify who "she" is in your comments. Are you talking about the elderly property owner or someone else? Also by "form of speech" did you really mean "figure of speech"?
Comment: The image doesn't display the phrase "snake in your ear" at all.
Comment: Note that the image is no doubt intended to reflect the biblical reference mentioned earlier.

What does ‘Snake in my ear” mean?


I want to use java 1.6 with lotus Notes 6.5. Is there a way to do that..? –

Question: I want to use java 1.6 with lotus Notes 6.5. Is there a way to do that..? –
I wanted to use prabalePrime method of BigInteger class which is available since java 1.4 and above, But Lotus notes 6.5 only supports java 1.3. Is there any way to use higher versions of java say java 1.6 in lotus notes 6.5?
Any help will be great!!
Thanks in Advanace!!
Answer: In short you should upgrade to R8.5. You cannot import the 1.6 JRE into a notes environment seamlessly as the Agent based functionality is wired up to the IBM JVM in Notes, also if you attempt to modify the IBM JVM built into Notes, you will invalidate your company's support and maintenance agreement with IBM. But seeing as you're using R6.5 which is no longer supported, you could give it a go, but this would require an update on every workstation, and you can't guarantee that you won't break anything in the process.
I had to use Kerberos for my company, and the IBM JVM that IBM wired into Notes had some annoying limitations, (typical IBM), so we had to also write for a higher JVM. This is what we did.
So, assuming you want to run from a Notes client we found that we had to write a jar file that runs on your workstation's JRE, (not IBM Lotus Notes' jvm), which was 1.6, and then make calls from the Notes client agent to run a batch file that executes the JAR with the workstations JRE. The separate JRE is making calls back to Notes to write data onto servers. This is very ugly, and technically we're not running under Notes any more, in fact we're running a separate java process, that is launched by Notes. When it comes to s/w, IBM make half-baked stuff or "space shuttles to get the milk", but you still have an obligation to stay current if you want to use their tech.
If you do elect this painful approach, you will need to enable "Don't prompt for a password from other Notes-based programs", which is in your "User Security" settings under "Security Basics".
So, tell your manager to bite the bullet and upgrade.
Comment: If work arounds could be classified by populations in the world, this is the "China" workaround. More sense to upgrade.
Answer: You can use any version of Java that you want for standalone programs, but if you need to run as an agent inside the Notes client or Domino server you are unfortunately stuck with the version that is supported by IBM and integrated into their code.
Comment: yes that is what i was trying to figure out. I wan to use it in an agent. Now I need to figure some other way round. Thanks for help..
Comment: The problem you may face with a standalone program is that the Notes.jar / NCSO.jar are only certified against the same JVM the Notes client supports. So while they may work in later JVMs, it is not a given. You may have to write out your answer to a file and pass it back to the agent.
Answer: Upgrade! R6.5 support ended almost 2 years ago.
Comment: Yes I am aware of that..BUt the company for which I am working has no plans upgrading...so no choice...
Comment: You cannot have it both ways. If you want to use the latest (or later) Java you should use the latest (or later) domino. Be sure to factor into your cost estimates the expense of not upgrading.


Moving Forward with Code Iteration

Question: There are times when working on my programming projects, and I get to a point where I'm ready to move on to the next part of my program. However, when I sit down to implement this new feature I get stuck, in a sense. It's not that I don't know how to implement the feature, it's that I get stuck on figuring out the best way to implement said feature. So I sit back for a day or two and let the ideas ferment until I am comfortable with a design. I get worried that I may not write something as well as it could be, or that I might have to go back and rework the whole thing; so I put it off. This is a big reason why I've never really finished many personal projects. Anyone else experience this, and how do you keep your self moving forward in your project?
Answer: My advice is to not get "stuck" on trying to come up with the best way to do something. Just do it! It might totally suck, but the bottom line is that you still did something. Nothing trumps experience...so just do it and learn from your mistakes.
Comment: I agree, although a day or two of pondering the best way to re-implement something can be very good and improving the code in the long run.  A lot of people believe they need to ouput x lines of code everyday to be productive, when some of the best coders put out 'less' code but which is much higher quality
Answer: Actually, writing it the wrong way and then having to go back and rework it can be a good learning experience. We can sit all day and think about the best way to implement the feature, but that's not going to be nearly as informative as actually writing the code and observing how it works.
So just go with your first idea and see how it works. Learn what's right and what's wrong. Then you can rework it or rewrite it as necessary; it will be easier the second time because you've got experience.
Answer: I would say write an acceptance test (BDD/TDD) to confirm the feature is complete and then write the simplest possible solution and when it comes to times to refactor you have the confirmation of the acceptance that you have not broke it
Answer: This is the same problem I've been having.  It's a personality disorder.  I'm trying to subscribe to the Sit down and do it philosophy.  It's difficult, as it results in some refactoring.  BUT, in the same time that I could've done nothing ("thinking"), I've accomplished something, and have moved the development forward.
This usually happens when the specifications aren't properly spelled out.  Since we're single-developers we set the specifications, and have too many options.  Just nail one down (the first one the comes to mind) and go with it.
I've had many times where I forced myself to sit down and implement Option 1, only to realize (from actually using Option 1), that it's a bad option.  I had to discard all changes and start over.  But there's no way I would've known unless I implemented it (or could've guessed how and where it will go wrong in the future - very difficult without tight specification and a crystal ball.)  But in the mean time I've programmed something, and know the result won't work.  Vs. spending that day thinking and accomplishing nothing.
Also, if you're overworked, don't confuse it with "thinking" about a solution.  If you need rest from programming and the development-cycle, then take a break.  Don't do any active thinking.  Just write a short to-do / "what I was thinking" before you take the day break.  Set an alarm in a few days to start back up, and program Option 1.  Refactor.  Discard.  Option 2. Next.
Answer: Two strategies: 1) work on other parts of the project while you give that one time to "stew". 2) Write something you can live with, even if it may be sub-optimal. I prefer the former as a rule, but sometimes decide I can live with the latter, at least for a short time. Frequently, especially after users play with things a bit, it turns out the whole general area needs enough revision that the general direction I was thinking would be better is entirely irrelevant.
Answer: I do
I try to avoid writing code until it seems perfect. Once i realized that almost any personal project (if it's big enough) is doomed to endless evolution, so i decided to focus on creating a library of useful classes: animation manager, custom event subsystem, some uis, wrappers for playing media etc. And from that moment every time i need to implement anything - new features or projects - writing new code and creating new entities comes along with evolution of my beloved lib. By the way i'm going to share it when i consider it perfect ;)
Answer: As someone said, Just Do it - You will have issues and challenges but keep moving forward, everyday implement very small feature and see it working, this will give you lots and lots of motivation to keep going.
I need to see some success, does not matter if it is small one also, to keep me motivated and moving.
Never ever give up.
Answer: Write a simple/naive implementation that works. Hard code stuff if you have to. Check in the code. Then refactor it to make it nicer. Or, if you like it, write some tests before refactoring.

Moving Forward with Code Iteration


Regular polygon with vertices on grid

Question: Constructing regular polygons on a sheet of an orthogonal lined paper - a regular maths notebook - I pondered on what would it take for the polygon to have it's vertices at the intersection of the grid lines.
(We could consider the paper infinitely spanning in all directions)
Answer: The only regular polygon that you can draw with vertices on the standard integer lattice is I'm afraid the square. I won't explain how to draw that!
We might as well consider polygons drawn in the Cartesian plane with vertices at rational points, and we might as well take the centre of
our polygon to be the origin. Let $P$ and $Q$ be adjacent vertices
with position vectors $v$ and $w$. Then $v\cdot v=w\cdot w=a$ say and $v\cdot w=a\cos(2\pi/n)=b$ say. We need $a$ and $b$ to be rational, so that $\cos(2\pi/ n)$ must be rational. But $2\cos(2\pi /n)$ is an algebraic
integer, so it must be an ordinary integer. We reduce to the cases
$n=3$, $4$ or $6$.
If we can draw a regular hexagon in $\mathbb{Q}^2$ we can draw an
equilateral triangle, so let's focus on that. Embed our plane in three
dimensional space, and consider the vector product $v\wedge w$.
Then $|v\wedge w|^2=(v\cdot v)(w\cdot w)-(v\cdot w)^2=a^2(1-\cos^2\pi/3)
=\frac34 a^2$. But $v\wedge w$ is a rational multiple of a unit vector
perpendicular to our plane, so $|v\wedge w|^2$ is a square of a rational. Oops!
I suppose one could look at good approximations to regular polygons
drawn on the integer lattice, or regular polygons in integer lattices
in dimensions $3$ or more.
Comment: Indeed, we can find a regular triangle (and hexagon, even a tetrahedron) in $\Bbb Z^3$.
Comment: Equilateral triangles and hexagon can be drawn in _three_ dimensions.  Start with the plane passing through  $(1,0,0), (0,1,0), (0,0,1) $.
Comment: Sadly, it's the truth.
Comment: One can draw a good lattice approximation to an equilateral triangle
by finding a rational approximation to $\sqrt3$, say $\frac ab$, then drawing the points $(0,0), (b,a),$ and $(2b, 0)$. The convergents of $\sqrt3$ quickly produce triangles that are indistinguishable from equilateral. For example, the convergent $\frac74\approx\sqrt3$ gives a triangle with vertices $(0,0), (4,7), (8,0)$, which has one side of length 8 and two of length $\sqrt{65}\approx 8.06$, an error of less than 1%. The next convergent, $\frac{26}{15}\approx\sqrt3$, gives a triangle that is correct to 1 part in 1800.
Comment: I come across this answer of yours only after asking [this question](https://math.stackexchange.com/questions/2251555/drawing-approximated-regular-shapes-on-square-grid) of mine. Well, I am obviously one that "could look at good approximations etc", my question is whether you, writing that line, were aware of someone doing the same before me. Thank you @Lord

Regular polygon with vertices on grid


Mount Android file system on Windows or Linux

Question: I want to edit some files on my phone, but I can not access the root folder on my phone.
I'm using a rooted Google Nexus 5 running Android 5.0. I can read/write to my /, and /system by using the "ES File Explorer" Android app, but not Windows software.
How can I mount the Android system file in Windows, so I can read/write to the same places from there? If that's not possible on Windows: I'm also using Ubuntu. So, can I mount my phone under Ubuntu?
Answer: I cannot answer the Windows part – but the Ubuntu part I can answer for sure, as I'm using that as well and mount my devices from my computer, sometimes with full r/w access. What I use needs ADB tools to be installed on your computer. If you didn't already install them, see e.g. Is there a minimal installation of ADB?
Prepare your Droid
First a basic requirement, applying to any OS which might run on your computer: To be able to get full access, the ADB daemon needs to be running in root-mode. This is not the case with stock ROMs, even if rooted, by default (though many custom ROMs have it enabled by default). So first check: If an "ordinary" adb shell directly brings you to the root-prompt (#) without invoking su, you're fine. Otherwise, you will need a helper like adbd insecure: Run it, and enable the "patched insecure mode". Optionally check the box to have that accomplished automatically on every boot of your device.
Prepare for write access to read-only file systems
Second, again independent from the OS on your computer: to read and write to file systems, they need to be mounted in read/write mode. You can accomplish that via adb shell anytime you need to write there (I don't recomment leaving those partitions in permanent read/write mode), e.g. issuing a mount -o remount,rw /system for the /system partition.
Mount your Droid
Now let's go for the specifics. I mount the Android file system via ADB, utilizing FUSE. The tool for that is adbfs-rootless. Compiling the code is easy given the instructions there; that done, copy the resulting adbfs binary to a directory in your $PATH. Then create a mount-point on your computer; in my example, I will use ~/droid for that. Now here we go:
# Mount the Android FS:
adbfs ~/droid
# Unmount it again:
fusermount -u ~/droid

To ease the process, I've created two aliases:
alias mdroid="adbfs ~/droid"
alias udroid="fusermount -u ~/droid"

You surely already have guessed: mdroid stands for "mount droid", udroid for "unmount droid".
A different approach to manually mounting/unmounting is using Midnight Commander with a specific VFS: mc-extfs-adb is doing that. A version I've spefically adapted for Ubuntu is available in the download area at IzzyOnDroid, where you can simply pick it (installation instructions included).
Both variants have their pros and cons: mc-extfs-adb takes quite a while on first access (while it caches the entire file system structure) – but then is pretty fast browsing the file system (as it is cached), only slowing down when you copy/edit files remotely. Using adbfs directly starts up much faster, but then always "hesitates" for a second when switching directories (as it does not cache the entire structure, but only reads on demand). I usually prefer the latter, but YMMV – hence I've given you both options :)
Comment: I've followed what you said, when I implement the command "adbfs ~/droid" my pc show "droid has been connected", the terminal show "--*-- exec_command: adb shell ls" but when I click on the device symbol, It show "Unhandled error message: Error when getting information for file '/home/peter/droid': Transport endpoint is not connected". What must I do now?
Comment: The first part (what the terminal shows) is normal and expected behavior. As clicking in the shell doesn't do anything, I don't know what "device symbol" you mean; you should rather `cd` to that folder, or (using your file explorer) navigate to `/home/peter/droid` (the "local" directory) instead of some device. For file operations, I'm not the "graphical guy" ;)
Comment: This is what the terminal show
    peter@peter-N56VV:~/adbfs-rootless$ ./adbfs /droid
    --*-- exec_command: adb shell ls
    peter@peter-N56VV:~/adbfs-rootless$ /home/peter/droid
    bash: /home/peter/droid: Transport endpoint is not connected
Comment: Do you have the device connected, and *USB debugging* enabled? What does `adb devices` show? I've never seen that error message, but somehow "Transport endpoint is not connected" seems to indicate there's nothing on the "other end" that could be used.
Comment: adb devices:
List of devices attached
04b713228291c6d0 device

The USB debugging mode is enabled.
Comment: Uh, looks like you've run into [issue #3](https://github.com/spion/adbfs-rootless/issues/3 "this does not work for lollipop?") – please follow up to that Github ticket, fix is there.
Answer: There's a second way, which should work with multiple operating systems on the computer's end: Taking a look at my list of file Android server apps, you can find some Android file-server apps using WebDAV or Samba, and SSH Clients & Server has some for SSH. Check those with "root capabilities", as you want to access the entire file system read/write.
Preparing your device for read/write access is done the same way as specified in my other answer. Then start the "server-app" you've selected, and you should be ready – not even a cable needed, as this works via WiFi:

Linux supports SSHFS, i.e. mounting the file system via SSH. There are also helpers to achieve this on Windows (listed there)
Samba is supported as "Samba" on Linux, and should be natively supported on Windows as "Windows Share"
WebDAV should also be supported by both systems

So with any of the three categories, you should be able to mount your Android's file system under Linux as well as Windows. Only possible "drawbacks" here are that you need an additional app on the Android device, and it might be a bit slower due to WiFi (the latter must not necessarily be the case, though).
Answer: Windows File Explorer by default doesn't let you access the Android root files. You'll need to download a different application (to your PC) for that. Many places (like this guidingtech.com tutorial recommend Android Commander. Another recommended file explorer program is Droid Explorer.
Comment: If you need a specific application to interact with the Android device's file system, that's not answering the question. Mounting a file system makes it available system-wide, for any application. If the question would be "how to copy files", there are many fine applications for that – Ryan's *Droid Explorer* definitely being one of them (the dev is active here as well ;)
Comment: It is answering the question as in how you see and read/write the android system's root files on the pc.
Comment: Yupp, it answers that part of the question, you're right. Maybe I take it a little to literal, as the title says ***mount** android file system*. It's definitely a useful hint – which the OP might wish to follow, lacking alternatives on Windows :) So thanks for bringing this in!
Answer: Install FX File Explorer from the Play Store, give it root access, and change it through the filesystem.


Changing permalink of default Post with custom post

Question: I have created new post type for jobs and i was using the default post for my blogs. Now the issue arisen for the jobs permalink as i was using example.com/blogs/%postname% earlier now i want on jobs is example.com/jobs/%postname% but it is showing up like example.com/blog/%postname%(that is my posted job title)
Answer: If you have your permalink structure set up as /blogs/%postname% then the post type will assume you want this for new post types as well. You'll need to define rewrites for the jobs post type by using the rewrite rule.
'rewrite' => array('slug' => 'jobs', 'with_front' => false)
Make sure to flush your permalinks afterwards by going to your WordPress dashboard, navigating to Settings -> Permalinks, and clicking "Save Changes".


Most compact high voltage source for making long arcs

Question: Out of curiosity, I have a question about high voltage electricity sources. Hypothetically, the requirements are that the source must be no larger than a water bottle (although smaller is better), and that the source is capable of producing an arc at least 1 meter in length (longer is better). The source doesn't have to be able to output continuously and can be pulsed, although the time between pulses should be no longer than 1/2 of a second. I am aware that tesla coils can produce large sparks in small packages, but I do not know if they would be the best option for the hypothetical situation or if they are even capable of meeting these criteria. Perhaps some sort of capacitor array?
Answer: You will need 3 × 10^6 V (three megavolts) to achieve a spark in dry air. That's rather a lot.
However, people have built hand-held Tesla coils that achieve roughly what you're asking for: http://www.rmcybernetics.com/projects/DIY_Devices/plasma-gun-2.htm (and they'll even sell you the parts!) As "Guess Who" points out, it's quite a challenge to avoid insulation breakdown inside your device.
This exploits the tendency of charged sharp points to spray ions into the air, reducing the breakdown voltage considerably.
Comment: That gun is awesome +1
Comment: Thanks for the input! This is why I love this website - there's always knowledgeable people willing to help and suggest really cool solutions.
Answer: The (hypothetical) requirements for your device are insanely unrealistic. Air breakdown voltage (voltage required to create a spark of a certain length through air) varies based on a ton of things, but in general, the "standard" value (all variables aside) is about 3x10^6 V/m. That's a huge voltage. I remember hearing from a professor once (and this could be outdated or completely wrong information) that on even the best of days, it takes about 100,000 volts to create an inch of spark. To create a spark that's a meter long, with circuitry that's the size of a water bottle is, dare I say it, impossible.
Comment: Well I did say hypothetical! I certainly wouldn't say impossible though. According to your "standard" value of 3,000,000 volts, I'd say I've heard of stun guns "claim" to have voltages exceeding that voltage, although it would only last for a short time, like a lightning. I said that the source could be pulsed. My question- would it be hypothetically possible to have an array of capacitors, or super capacitors, that can discharge a voltage around 3,000,000 volts that is the size of a water bottle? Also, if so, how fast (at what rate) could said hypothetical capacitor(s) charge and discharge?
Comment: Dielectic breakdown will be your main problem with trying to build a 3MV capacitor; it'll just leap straight across the plates, or through several centimeters of polyethylene insulation.
Comment: Well, a mere 500kV can get you a spark way bigger than 1m: http://www.youtube.com/watch?v=PXiOQCRiSp0


Jenkins Docker Behind Reverse Proxy Adds ":80" to the URL

Question: The Jenkins container redirects to URL:80, which is causing an error. When I remove the :80, everything is working as it should.
I have tried the proxy with a simple web app and there were no issues.
This is the docker-compose.yml https://pastebin.com/djJTuBZL.
The cert is correctly issued and the connection is secured. The host I'm using is live and correctly configured with ports 80 and 443 open.
The container exposes 8080 and this is the same as the VIRTUAL_PORT.
Also, I would have assumed that accessing an address with :80 wouldn't have caused any issues this being the standard HTTP port eg www.google.com:80; unless I'm missing something.
If this helps this is the logs when I run docker-compose up https://pastebin.com/NUbDL7PC.
Here are the logs when I try to do the first login, the space is before I remove the :80 then load the page https://pastebin.com/0wxGDBzi.
How can I resolve this problem?
Answer: If it's a brand new Jenkins, you can try creating an SSH tunnel directly into the container with port 8080 and checking if the problem also appears there. That will at least allow you to check if it's Jenkins redirecting you or Nginx.
There you can also try adjusting "Jenkins URL" in "Manage Jenkins" -> "Configure System".
Alternatively, check  jenkins_home/jenkins.model.JenkinsLocationConfiguration.xml. jenkinsUrl tag is also present there.


How to pack chilli Powder

Question:
I packed chilli powder to transparency polythene bag. It expires very quickly. But when I put chilli powder into plastic bottlle I can remain it for long time. How can slove this?
  Thanks
Comment: It's not clear what you're asking?  What are you trying to solve?
Answer: In a word, you can't.
The issue is with the bag vs. the bottle. Both are made out of (essentially) the same thing. But the bottle is thicker and 'breathes' less than the bag. In a word it is less porous.
Plastic bags are not good long term storage, especially ones you buy at the grocery store. What you need to do for maximum shelf life is (at least) a plastic bottle.
Me, I make chili powder every 6 - 8 months and store it in a glass container in my pantry. It stays reasonably fresh the whole time.
So the hierarchy of storage goes something like this.
<code>Paper bags, plastic bags, plastic containers, metal/glass containers
</code>
With the left most items being more porous than the one to it's right.

How to pack chilli Powder


Forced air furnace filter gets wet with water while A/C is ON

Question: Noticed lately when it has been extremely hot, and my air conditioner is constantly turned on, that my furnace filter get soaked wet.  Took it out , opened the furnace door to check, but there was no water on the inside of the furnace floor, but only in the slot where the furnace filter slides in.   Have been drying the filter (aftre shutting the system off) and reusing it.   A/C works fine, with super cold air.
Any help is appreciated.
Answer: Check the condensation drain path from your evaporator for blockage or leaks. There may be a tray with a tube attached. They tend to rust through over the years, but it could be mineral buildup or the result of insects blocking it.

Source and read more
Answer: Condensate drainage can get clogged. Check your condensate drainage lines and reservoir.
Comment: Thanks much.  The condensate plug at junction of tray and the drain pipe was heavily clogged.  Blew air in pipe and cleaned the plug.  Problem solved.   How do I check the tray for future, as it is sealed inside the duct ?  Also , how do I check for any rust in heat exchanger, for coming winter months.
Comment: There *should* be a place on the unit where you can view it....usually with a flashlight while lying on your side... I would check it every 3 months. Glad you found it, sir


Do Enchantments on Weapons Scale with Sneak Attack Bonuses?

Question: Recently I've built a character on Skyrim who focuses mainly on sneaking and bursting to death any enemy and I'm trying to max out my damage. I have been testing what I already have and with sneaking + 2 daggers I've one shot Sahloknir and Arngeir. My current build is Ebony Dagger + Blade of Woe x30 (x15 With Daggers Perk x2 for Jesters Gauntlets/Shrouded Gloves) which adds up to 1140 damage, but this lead to my question. Do enchantments like Absorb Health and Frost Damage scale with the x30 Sneak Attack, I'm just trying to max my damage. Any help would be appreciated, thanks.
Answer: No. They don't. Tested it extensively myself. Would have been sweet tho. esp for life-steal ;)
but it would be overkill, so they didn't.
Answer: Since you state that you are trying to max your damage with these weapons, there is a way to boost the damage of some weapon enchants.  It's just not with the Stealth skill tree.
Both of the Enchants you have asked about benefit from the Destruction school.
Good news: Frost related perks in that school will carry over to the Frost Damage Enchant.  Each level of Augmented Frost will add 25% to the enchant's damage.  The Deep Freeze perk should also add a Paralysis effect to victims under 20% health.  Oh, and if you're really intent on adding insult to injury that Paralysis effect should benefit from Alteration's Stability.  Additionally, both Enchants will eat less of the weapon's "soul food" if you have a high Destruction skill or if you equip any enchants that lower the mana cost of Destruction spells.  Also note that using these enchants will provide a slight trickle of Destruction XP.
FWIW:  Weapon enchants that don't use the Destruction school are dependent upon Illusion (Fear), Restoration (Turn Undead), Alteration (Paralyze), and Conjuration (Banish, Soul Trap & Fiery Soul Trap).
Details can be found here.
Comment: You don't specifically say how this increases damage. I assume it's included in "frost related parks", but I don't really remember the destruction perk tree.
Comment: @DCShannon, I've edited my answer to include some of the details from the original link.


Difference between Voltage source and Current source?

Question: So what's the difference between a Voltage source and a Current source? Aren't they the same? Because after all they are related with the formula \$V = IR\$. So it means that If we produce a voltage, there should be a current and vice-versa. So really what's the difference?
Comment: I don't want to add to the flurry of similar answers below, but I do want to point out that when an ideal voltage source or and ideal current source is used in circuit analysis it is not necessarily true that the source provides power to the circuit. For example, we might _model_ a zener diode as a voltage source but it absorbs power.
Answer: Voltage and current sources are not related by \$V=IR\$. This applies to resistances. However, you can connect a resistor to a voltage and current source, and then see what happens to voltage across the resistor and current through it.
A voltage source will maintain a constant V, regardless of the load connected to it. A current source will maintain a constant I, regardless of the load. Consider what happens as R changes in these two cases:

simulate this circuit – Schematic created using CircuitLab
For the case on the left, consider the resistance \$R\$, and the voltage across it \$V_R\$, and the current through it, \$I_R\$:
R   Vr  Ir
0Ω  1V  ∞A
1Ω  1V  1A
2Ω  1V  0.5A
3Ω  1V  0.33A
4Ω  1V  0.25A
∞Ω  1V  0A

Now consider the case on the right:
R   Vr  Ir
0Ω  0V  1A
1Ω  1V  1A
2Ω  2V  1A
3Ω  3V  1A
4Ω  4V  1A
∞Ω  ∞V  1A

In all cases, \$V_R = I_R R\$. On the left, \$V_R = 1V\$ (by Kirchhoff's voltage law), so \$I_R\$ is whatever it needs to be to satisfy Ohm's law.
On the right, \$I_R = 1A\$ (by Kirchhoff's current law), so \$V_R\$ is whatever it needs to be to satisfy Ohm's law.
Also notice that 0Ω is equivalent to a short circuit, and ∞Ω is equivalent to an open circuit. In some cases this results in infinite voltage or infinite current, which is an indication that these things can't physically happen. For example, if you actually short out a real voltage source, like a battery, the wire has actually some small resistance. A lot of current flows, but not an infinite current.
If you like, you can think of a voltage source as something that moves current, but adjusts the amount such that a constant voltage is maintained. You can think of a current source as something that adjusts the voltage across itself so that a constant current is moved. Realize of course that you are endowing the power of thought to inanimate objects, which isn't really true. Really all that's happening is that a current or voltage source introduces one constraint to a system of equations that must be solved.
You should also think about what happens when the thing connected is not a resistor. For example, what if it's a diode, like an LED? The voltage source still attempts to maintain a constant voltage, and the current source attempts to maintain a common current, but no longer is the equation being solved \$V=IR\$. That describes the behavior of resistances, but now the equation will be something else, describing whatever it is you have connected.
Comment: @akki I don't see what was wrong with my grammar, and otherwise you just added a lot of words that I think made the answer *harder* to read. I've rolled back your edit.
Answer: A basic voltage source produces a constant terminal voltage. Let's say it produces 1 V. When 1 ohm is connected across it, 1 A will flow. When it is open circuit the terminal voltage is 1 V and no current flows. When it is shorted infinite current will flow.
A basic current source is different. Let's say it produces 1 A. When 1 ohm is placed across its terminals, 1 volt will appear due to ohms law. When it is open circuited infinite voltage will appear across its terminals in order to continue driving 1 A through fresh air! When shorted, 0 V appears across its terminals and 1 A is flowing.
Comment: So suppose I connect two resistors in series with a current source but parallel to each other. Does that mean that the current source will drive 1 A through each resistor??
Comment: @TheDreamCoder17 the source can only see a single load, that is the combined resistance of the two resistors. The 1A will be shared between the two resistors, if they are equal then each will get half the current if the curent will be shared according to the resistance relation between them.
Comment: @TheDreamCoder17 the changes you made to my answer were misleading and I have taken the answer back to what I put. You have asked the question because you don't know the answer. If you feel you do have a better answer then post it as your answer please. For instance - in the version you modified you suggested that a voltage source modifies the current output to suit the load in order to maintain the voltage. NO, it doesn't do that - it produces a voltage PERIOD and the load takes whatever current it wants. This is an example of how your modifications were misleading.
Comment: @Andyaka I agree with your rollback (that was a radical change), but I think it's wrong to say that thinking of voltage sources as things that adjust the current they pump in order to maintain a constant voltage is wrong. I think of voltage sources that way. Of course, it's personifying an inanimate thing, but it's a natural way to reason. I can also "confuse" a voltage source, for example by connecting a negative resistance load. An ideal voltage source may not be "confused", but real voltage sources (say, batteries) will be.
Comment: I appreciate that @Andyaka...
Answer: You fix the current source to a specific number of AMPS and then it will deliver it no matter what and it will adjust it's voltage to keep that current constant. So in that case only voltage varies. For the Voltage source you fix the voltage to a specfic Voltage and it will stay constant. It will pump out as much current as is necessary to keep the Voltage constant. In that case only current varies.
Answer:
Because after all they are related with the formula V = IR. So it means that If we produce a voltage, there should be a current and vice-versa. So really what's the difference??

The difference is that a constant voltage source tries to maintain the V parameter in the above equation constant (irrelevant of the current level) while a constant current source tries to maintain the I parameter constant (irrelevant of the voltage level), so the resulting effect is quite different.
Ideally a constant voltage source will have an unlimited current capacity so will be able to provide as many amperes as needed to the load and keep the voltage steady.
In reality when the load impedance changes and it tries to get more current than what is available the voltage will drop lower than the set value.
With a constant current source things are slightly inverted, an ideal current source will have an unlimited voltage potential ability in order to increase the output voltage as high as needed in order to keep the load current steady (when the load impedance increases).
In reality when the load impedance increases and the current source has reached the max voltage level it can provide the current will drop lower than the set value.
Answer: A voltage source is assumed to deliver energy with a specific terminal voltage which does not depend upon the current from the source. A current source on the other hand is assumed to deliver energy with a specified current through the terminals.
Both current and voltage sources are ideal. In practice, we represent a real voltage source as an ideal voltage source in series with a resistance and a real current source as an ideal current source in parallel with a resistance.
Answer: Since student times, a curiosity about what is the basic difference between capacitor and inductor discharge, drive me to learn and simplify the issue of constant voltage and current sources.
Later I was discover the usefulness of this achievement in circuit analysis and synthesis, replacing the active parts like zener and transistor with equivalent constant voltage and constant current sources respectively.
First of all there are DC as well as AC sources
but what is an Ideal Voltage Source?
An ideal "voltage source" is simply an element providing voltage across its output that does not depend upon the current flowing, and a practical Voltage source is a kind of Voltage source whose internal resistance is very low! Such that the supplied voltage does not changes even if the external load resistance is changes.

And what is an Ideal Current Source? A current source which provides a constant current without any relation with the voltage supplied to the load is called Ideal Current Source, and in practical current source, internal resistance is very high compared to the external resistance of the circuit but not infinite.

An interesting point of this basic theory is that we can modify (or convert) current to voltage source and vice versa.
How?
-Constant Current Source into a Constant Voltage:
Find the resistance parallel of the Constant current source and place it in series with the current source to convert it into a Constant Voltage Source.
-Constant Voltage Source into a Constant Current:
Find the Internal resistance of the Constant Voltage source and place it in parallel with the Voltage source to convert it into a Constant Current Source
So the answer to your question on how this two type of sources are related with ohms low is that the current source (If) is equal to voltage source (Vf) divided by the resistor If=Vf/R
Sourses in this very simple form are dependend some how by the load variations, so you have to balance the circuit variyng the series or the parallel resistance accordingly.Souch a dynamic resistor it is a transistor offcourse, making your source more independed.
There are several physical voltage source like batteries (except the underdevelopment nuclear batteries!) , as well as current sources like photoelectric cells.
There are lot of practical source circuits. For example your bench PSU that have adjustable output voltage and current limit, then based on the load connected, the supply will automatically switch to constant current  from constant voltage when current limit condition is satisfied.
The symbol of a voltage source is

to indicate a device which can produce a continuous force to move the electrons (or, continuous voltage) through the wire connected into the two terminals of the device
The symbol of a current source is

to indicate a device which provides the regular flow or electrons or current on a circuit.


Relationship between tail behavior of a density function and the radius of convergence of its Taylor expansion

Question: Given a continuous probability density function $f(x)$, whose Taylor expansion is $f(x) = \sum\limits_{n=0}^\infty a_n x^n$ with radius of convergence $r$. Can we say something about the relationship between $r$ and the tail behavior of $f$? For example, for the normal density, $r=\infty$ and the it has a somewhat "light" tail. However, for the standard Cauchy density, $r = 1$ and it has a heavy tail. Another example is the logistic distribution, which has $r = \pi$ and a tail heavier than normal but lighter than Cauchy. I guess in general, a density with heavier tail should have smaller $r$. Can we find the explicit relationship?
Comment: Information about tails would come from the Taylor expansion about $\infty,$ not $0$.
Answer: The only information in the tail of the expansion of f is the coefficients $a_n$ for $n \gg 0$.
The relationship is
$$\frac{1}{r} = \limsup_{n \rightarrow \infty} \sqrt[n]{a_n}.$$
For many standard examples the limit exists so that $$\limsup_{n \rightarrow \infty} \sqrt[n]{a_n} = \lim_{n \rightarrow \infty} \sqrt[n]{a_n} = 1/r$$.
In light of whuber's comment on the OP, are you asking about the tails of $f$ as a Taylor series or the tails of the distribution $F(t) = \int_{-\infty}^t f dx$?
Comment: This answer, although containing correct information about the radius of convergence, is telling us about the tails of the sequence $a_n,$ not about the tails of the distribution $f$.


How to solve this PDE with method of characteristics?

Question: I have this problem $$y \frac{\partial u}{\partial x}-x\frac{\partial u}{\partial y}=1,\\u(x,0)=0$$
Using the method of characteristics I have
$$\frac{dx}{dt}=y \\ \frac{dy}{dt}=-x \\ \frac{du}{dt}=1$$
Then $$\frac{dx}{y}=\frac{dy}{-x} \\ x^2+y^2=\eta $$
and
$$u=t+\xi$$
But I do not understand how solve this problem.
Answer: You have done well so far. The system of ODE's is correct. Notice that $\xi=0$ due to your condition $u(x,0)=0$. However, your method to invert the $x$ and $y$ coordinates does not lead you anywhere. The following method to solve the system will be more useful.
$$\frac{d}{dt}\left(\frac{dx}{dt}=y\right)\implies\frac{d^2x}{dt^2}=\frac{dy}{dt}=-x$$
$$\implies x=c_1\sin(t)+c_2\cos(t)$$
Now we can find expression for $y$.
$$\frac{dy}{dt}=-c_1\sin(t)-c_2\cos(t)\implies y=c_1\cos(t)-c_2\sin(t)$$
We now use the given boundary condition $u(x,0)=0$ to find the constants $c_1$ and $c_2$.
$$y(0)=c_1\implies c_1=0$$
$$x(0)=c_2\implies c_2=x_0$$
Thus
$$x=x_0\cos(t)\quad\&\quad y=-x_0\sin(t)$$
We must invert these equations. Because they are nonlinear, we must be clever. First divide $y$ by $x$.
$$\frac{y}{x}=-\frac{\sin(t)}{\cos(t)}=-\tan(t)$$
$$\implies t=\arctan\left(-\frac{y}{x}\right)$$
Since you found $u=t$, we do not need to find $x_0$ and have arrived at our solution.
$$u(x,y)=\arctan\left(-\frac{y}{x}\right)$$
Answer: Write $x(t)=a\sqrt{\eta}\cos t$ and $y(t)=b\sqrt{\eta}\sin t$ where $a,b\in\{-1,+1\}$. Then $\frac{y(t)}{x(t)}=\pm\frac{\sin t}{\cos t}$ and so $t=\pm\arctan\frac{y}{x}$. If you substitute this in $u$ you get $u(x,y)=\pm\arctan\frac{y}{x}+\xi$. Now $u(x,0)=\arctan 0+\xi=0$ and so $\xi=0$. It follows that $u(x,y)=\pm\arctan\frac{y}{x}$. To determine the sign, note that
$$\frac{\partial u}{\partial x}=\pm\frac{-y}{x^2+y^2},\quad \frac{\partial u}{\partial y}=\pm\frac{x}{x^2+y^2}$$ and
so $$y \frac{\partial u}{\partial x}-x\frac{\partial u}{\partial y}= \pm\frac{-y^2-x^2}{x^2+y^2}=\mp 1.$$
Hence, we need $u(x,y)=-\arctan\frac{y}{x}$.


What steps to take in painting this damaged wall?

Question:
Water leak from above windows created bubbles.  I stripped the damaged section with putty knife, did I go too far? What steps should I take next? I'm new at this, I think I'm supposed to add primer and then a coat of paint.
Comment: Ed's answer below and the Onetime(r) product will work. The big thing is the leak is no longer present that created the problem to begin with.
Comment: I just don't understand why normal primer (sealer) is not preferred in this situation since the whole wall was done this way? Still solving the leak problem.
Comment: Yes, regular primer will work, please be certain the leak is gone and the wall is absolutely dry.
Answer: Did you go too far? I don't think you did. It is best to remove the loose material. I would use some topping compound and fill the area and lightly sand. This will give a normal look. If you just prime and paint it will be visible for years. I use topping mud where I need a thin coat. It sands easier then prime and repaint and you will have a professional looking repair.
Comment: Yes it looks like plaster, I would still use topping mud it is a softer lighter form of drywall mud. It is easier to put a thin coat down and easier to sand, anyplace that sells sheetrock / mud will have topping mud many places will have small tubs like a quart for a few $.
Comment: Never heard of topping mud before, what's it usually used for so I can know what to ask for? Btw this is not drywall.
Comment: I can find it if only I have a description people will understand since I'm in a non English country.
Comment: This store here has the most products but don't know where it is: http://www.cmbegypt.com/cmbgroup/products/admixtures/
Answer: Here is the over kill but guaranteed way to fix this. There are steps you can skip, but the paint may crack/peel/bubble/not stick if you do. Water damaged gypsum board can be tricky.
Remove any loose material. Lightly sand. Apply Zinsser Gardz. Allow to dry and lightly sand. Patch/skim with spackle/mud. Allow to dry and lightly sand. Repeat application of spackle/mud and light sanding if necessary to achieve acceptable finish level. Apply Zinsser Gardz. Allow to dry and lightly sand. Finish with 2 coats of normal paint.
Comment: It can be hard to find the product or equivalent since I'm not based in US.  but is this the same thing which I got? https://www.reddevil.com/index.php?l=product_detail&p=912
Comment: No, that's not the same thing. Look for a primer that will either repair damaged wallboard, fix peeling paint, allow painting after removing wallpaper, or prevents bubbles after skim coating. If I were you, I would buy Gardz on eBay from anyone who will ship internationally.
Comment: I forgot to say my wall isn't drywall.


Using Mapbox with GeoServer or similar?

Question: I am doing some research and trying to understand how Mapbox compares to GeoServer (or any GIS server software), and whether or not they are used together or if using one precludes using the other. Can you/should you load services stored in GeoServer or similar in a Mapbox map? If you would not use them together, why would you use one vs the other. I'm trying to understand the main differences - it seems to be that Mapbox is more than just an API, perhaps a hosted mapping platform, but how does it interact with GIS servers/databases?
Comment: So the strength of GeoServer (and similar software like MapServer, deegree) is to provide services using standard interface protocols like WMS,WFS,WMTS, WCS, WPS.  These OGC web services are intended to be consumed by multiple clients, whether they be on the web through libraries like OpenLayers or on a Desktop like QGIS.  So if you want your data to be used in multiple locations, then you will need to set up such an OGC service.  AFAIK you can't serve OGC services with Mapbox.  You may be able to consume such services with Mapbox you'll need to check.
Comment: I'm not sure your question fits very well with the expected format for GIS.SE.  You seem to have many questions for example.  You say you have done some research, so you should perhaps show some of that research in the body of the question.  What is it that you want to do, share maps with others (so they can use it in their own clients), build your own web site...
Comment: My research was inconclusive on the question that I asked, which is why I posted it here. We are building our own website.
Answer: It depends a bit on what your goal is, with Geoserver (and other mapservers) you are in control of your data, as you provide the services. They do not cost anything (beside the infrastructure). But you have to care about the underlying server (hardware or platform as a service and software, security and so on), probably need an Apache/Ils/Nginx whatever configured, need to care about client side visualisation (JScript/Openlayers, PHP or others, as well as Symbology).
With services like MapBox you have less work to do but need to pay for it (beside the free version with several restrictions). There you have lots of stuff preconfigured.
That is in general the difference. For small / fast deployment a service like MapBox is probably nice (never used one though). If it gets bigger those services tend to become expensive, but you need some know-how and time to run services on your own.
And of course you can use them in parallel(if i understand you correct on this point). Its just the underlying data that needs to be yours and you can put them online in several ways.

Using Mapbox with GeoServer or similar?


What defines the name of a gambit?

Question: What defines the name of a gambit? To be obvious, if someone were to use a gambit often (of their own theory), you would name that gambit after them or so, right (like the Ruy Lopez opening)? How then do we get the names of the gambits?
Comment: Slightly different question, but the answer is in spirit the same: https://chess.stackexchange.com/questions/29043/why-are-openings-named-after-countries
Answer: There is no general rule in naming openings or opening lines in general or gambits. Sometimes it's the inventor, sometimes the place they lived, they were born, they played the line the first time, and so on. To make it more complicated, openings can have different names in different languages. In German, the Petroff defence is named Russian defence, and Benko Gambit is called Wolga-Gambit. The Sokolski is also called Orang-Utan. So there really is no general rule but in some cases some amusing histories.
Comment: One example of an amusing history is the [Halloween Gambit](https://timkr.home.xs4all.nl/tour/breeze.htm)
Answer: Depends- there's no real rule outside of "convention" and when a name's settled on by the community at large, it tends to stay that way (as openings in general). Often, it'll be named after a person who played it a lot, developed the theory, a country related to it by the nationality of one or more people that played/developed it (or otherwise related), or the opening name was just made up by someone. Also, a lot of the time opening names have just been.. forgotten why.
Also note that some openings including gambits are known by multiple names- the first gambit example to come to mind is the Benko Gambit, which is sometimes called the Volga Gambit in Eastern Europe.
So tldr: depends on the gambit, could be a bunch of reasons.
Answer: As the other answers indicate, gambits - and openings in general - can receive their names from different factors. A few examples:

The King's Gambit gets its name from opening with the king's pawn and gambiting the immediately adjacent flank pawn. The Queen's Gambit is similarly named, except the gambit is on the queen's side of the board.

Although the Budapest Gambit had been played previously, it seems to have taken its name from the location of the first time the gambit was used in a game of significance between high level players.

The Evans' Gambit gets its name from the man credited with inventing it (notably not GM Larry Evans nor IM Larry D. Evans).

The book Chess Opening Names explores the naming of several popular openings, including some gambits. The book has three sections, one each for openings named for: people, places, and "stories". (As I type this, I'm about half way through the audio version of the book - mostly listening while I'm driving. The chess theory is light, but I find the history interesting.)

What defines the name of a gambit?


Is it true that $\forall \epsilon > 0 , a \leq b + \epsilon \Rightarrow a \leq b$?

Question: Is it true? I see a lot of inequalities like that in proofs, but i don't understand why it should be true.
Comment: Your question is equivalent at $$\forall \varepsilon>0, a\leq \varepsilon\implies a\leq 0.$$ If $a>0$, take $\varepsilon=\frac{a}{2}$, then $a>\varepsilon$ which is a contradiction.
Answer: If $a\not\le b$, then $a>b$. Let $\epsilon=\frac{a-b}2$: then $\epsilon>0$, and $a=b+2\epsilon>b+\epsilon$, contradicting the hypothesis.


Replace image and javascript absolute paths through proxy_redirect in nginx

Question: I have a scenario as follows.
Nginx is being used as a reverse proxy to a apache server listening at port 8080. nginx is running at port 80. There is a wsgi application which is being run by the apache server.
Now, I have added a proxy_pass to the nginx configuration such that whatever requests come to localhost/ (nginx port is the default port 80) they get redirected to localhost:8080.
Here is an excerpt from the nginx conf file:
    server {
       listen 80;
       proxy_set_header X-Real-IP  $remote_addr;
       proxy_set_header X-Forwarded-For $remote_addr;
       proxy_set_header Host $host;

       location <app_name> {
                proxy_pass http://localhost:8080/
                proxy_redirect http://localhost/ http://localhost:8080/
       }
    }

I have added the proxy redirect to take care of any redirects from the apache server so that any request mapping to http://localhost/<something> gets redirected to http://localhost:8080/<something> because the application's resources are going to be available under port 8080.
Now, the problem here is that the wsgi application generates an html where the image and the javascript location paths are absolute paths like /img/image.png and /js/javascript.js. Now, they are part and parcel of the HTML and do not send any redirect with a complete http:// prefix as such therefore, the server tries to locate the images in the localhost/img directory instead of the localhost:8080/img directory.
A dirty workaround for the same could be to have the /img and /js directories also defined as separate "location" in the server config and a proxy_pass specified to them. But then these directories could be more in number and maintaining the same could potentially become a headache.
Is there a cleaner way of doing this?
This is in reference to fixing the issue in graphite Apache cannot serve graphite-web from URLs other than /
Answer: In case where the proxied application (the Graphite app in this case) isn't able to be configured as a "slave" app, it is better to spare a whole subdomain to the application.
Or you may try the ngx_http_sub_module which:

…modifies a response by replacing one specified string by another.

as an example this code will change all the ':/localhost:8080/' to ':/localhost/app_name/':
location <app_name> {
    # ...
    sub_filter ':/localhost:8080/' ':/localhost/app_name/';
}

Note that:

This module is not built by default, it should be enabled with the --with-http_sub_module configuration parameter.

But in most package systems nginx is built with all it's optional modules already. Just check if you version has the sub_module built in:
nginx -V | grep sub_module

In my case for homebrew it gives output like this.


How can I predict the folding of a synthetic protein?

Question: I want to predict the folding of a chimeric antigen receptor sequence. These sequences are completely made out of small parts of different proteins. Do you know if AlphaFold can be used for this?
Comment: Please clarify your specific problem or provide additional details to highlight exactly what you need. As it's currently written, it's hard to tell exactly what you're asking.
Comment: From @MaximillianPress's response, the answer is no because a chimera has no history the domains evolving together and that is a central part of the algorithms assumptions. Please do remember to mark an answer as "accepted" when the question has been successfully answered.
Answer: I'd consult references about AlphaFold. For example, wikipedia has a "Limitations" page on the tool, though the page doesn't mention anything about synthetic proteins.
The hesitation that I would have is that the tool relies to some extent on coevolutionary models of amino acids to infer interactions at both training and prediction steps, so throwing a synthetic protein at it may confuse it. See e.g. slide 10 here.
In an interview, they acknowledge this rather directly:

Now, if you have a protein which is completely new, which does not have an evolutionary history—a synthetic protein, which has just been designed— then our system would not be as accurate as it would be for existing proteins.

I am not totally clear on whether this is due to learning a latent representation of constraints on similar proteins, or whether the tool attempts to directly find homologs. The paper methods suggest to me that it is the former, but I'm not sure. They describe training on only chunks of a big MSA. If that's the case, I'd guess that they still can use information about the natural chunks of your synthetic protein, and aren't expecting to be able to do a full-length protein alignment.
So I think that you can expect the prediction to be relatively low quality. It is still probably much better than any alternative way of predicting structure!
As always, not a bad idea to post an issue on github asking this question.
Comment: This is a very good point indeed, it will rely on convolution as part of its algorithm and chimeras will not follow this assumption.


32bit to 64bit topology errors

Question: Can generating a shapefile from a pgdb cause topology errors due to floating point conversion?  I am running into gaps in a line layer of really small distances (order of 10^-4; CRS EPSG:2227 usft).
Answer: Shapefiles still store numbers using 64 bits of precision, 16-16 digits.  It looks like you need 11 or 12, so you should not get errors unless you are doing computations in which case floating point errors are a remote possiblility.
If anything is ever converted into a 32-bit floating point number you would definitely lose precision.
Comment: Great, thanks,  I wanted to make sure that the gaps were real and not computational artifacts before going through with fixing them.
Comment: You mean *coordinates* use 64 bit precision, numbers as attributes use less digits http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Geoprocessing_considerations_for_shapefile_output
Comment: @user, correct.  Numeric data is stored using dBase IV format (DBF file), which means as strings of digits.

32bit to 64bit topology errors


Fixing interfaces

Question: Ok so long story short, my raspberry I is no longer connecting to the Internet. I did some research and found that the interfaces file is not in the interfaces.d folder and I'm trying to move it. The I used not the sudo cp and sudo mv commands and they're not recognizing the destination. I've entered it as just "interfaces.d", "/ect/network/interfaces.d", and about a dozen variations of each. I need help.
Comment: Start again from scratch.  We have no idea what you have done and neither do you.
Comment: the `interfaces` file usually lives in `/etc/network` - see the [man page](http://www.unix.com/man-page/linux/5/interfaces/) - alternatively run `man interfaces` to get the same information as that page
Answer: I agree with joan.
The tutorial How do I set up networking/WiFi/Static IP describes the contents and locations of configuration files (assuming you are using a recent Raspbian - which you haven't specified).
There is ABSOLUTELY NO REASON to fiddle with <code>/etc/network/interfaces</code>.
If you have done any other damage you may have to start from scratch.

Fixing interfaces


How do multiple transmitters and single receiver work?

Question: I have multiple digital transmitters sending packets to an receiver, and packets from different transmitters may arrive at the same time, how can the receiver differentiate multiple packets at the same time given each packet carries an ID of the transmitter? Must each transmitter use a different channel in order for the receiver to differentiate them?
Answer: It really depends on how much expense and effort you're prepared to go to to get simultaneous reception of multiple signals.
You can divide your transmission space up in many ways; the most commonly referenced are:

Space Division Multiple Access (SDMA) - separate the space by physical paths
Frequency Division Multiple Access (FDMA) - separate the space by frequency (channel)
Time Division Multiple Access (TDMA) - separate the space by time
Code Division Multiple Access (CDMA) - separate the space by code (this is an implementation of Direct Sequence Spread Spectrum, or DSSS)

If you're any good at visualisation, it may help to think of each multiple access approach as a dimension in the overall transmission space.
Cellular telephony uses a combination of all of these methods (yes, SDMA too - look at a cell tower; they separate the transmission space into sectors using directional antennae). Hardwired networks like Ethernet use SDMA.  Radio stations (music, news, etc) generally use FDMA.  Each approach has advantages and disadvantages; the most obvious disadvantage of CDMA (which is arguably the "best" option) is the cost and complexity.
If you can't afford to do any better than FDMA (which is the absolute minimum you can get away with for radio transmission - don't be transmitting on other people's channels!) then you will need a communications protocol that is collision-tolerant; either transmitters can detect collisions and retransmit, or because it doesn't matter if data doesn't get through.
If you absolutely must get the data through on time then be prepared to spend money on a radio system that will do it.  An FDMA/TDMA combination (e.g. Frequency Hopping Spread Spectrum, or FHSS) is probably the best value for money in terms of cheap-vs-effective; if you can afford radios that do CDMA as well as or instead of TDMA then that would give you the best possible result.
Answer: Timeslot or frequency division springs to mind as the main solution for avoiding transmission clashes.
Time division multiplexing is used on cell phones nowadays but the older analogue phones used frequency division multiplexing.
Answer: Another type of system that allows for this is any of the Spread Spectrum (SS) systems - either frequency hopping (FH) or Direct Sequence (DS).  In these cases the there would be CDMA (Code Division Multiple Access) where you can have in band, simultaneous reception of different channels.  The Cellular signalling from Qualcomm (called CDMA) is SSDS.
Answer: i would use cdma ovsf codes to differntiate each transmitter. I will have a device that decorrelate each ovsf code to decode each transmitter.
Comment: I did not understand the down vote, the question seems to ask what ID to place for each transmitter, All I said is use OVSF codes which is what UMTS is using now. It helps you avoid shannon's limit on noisy channels characterized by the question. haaayayayay!


Should I add barriers to raise the height of my ceiling joists to contain new blown-in insulation?

Question: I am planning to add additional blown-in insulation to my attic space. Currently there is about 5" of old cellulose insulation. I plan on raising this to around 15" to achieve a rating of R50. I will no longer be able to see the joists after adding this additional insulation. I am aware of this being an issue for moving around in attic. My question is, should I keep the insulation contained to each space between joists (rafter bay, if that's what you call it)? I could use netting, plywood or foam board if need be.
Comment: If you use plywood to build up the sides of the joists to contain the insulation, then you still won't be able to walk across them.
Comment: Heh, good point @SteveSh. The barriers could become somewhat of an annoyance or hazard.
Answer: No. Covering the joists improves your overall insulation, since wood is not a particularly good insulator, and netting/barriers/etc will just make it even harder to move around.
Just bury the joists. If there are places you need to go on a regular basis, screw down catwalk boards. If you go there a LOT, make an elevated catwalk.
Otherwise, take a snow shovel with you and wear a dust mask for the rare things where you need to get somewhere to run a cable or check a leak or whatever. Rake the insulation you shovel aside back in place when the task is done.
Comment: I think blown in insulation is a PITA just for the reasons you mentioned.  It's a lot easier to move a fiberglass batt or roll out of the way, then put it back.
Comment: Yeah, I would sister some taller joists (doesn't need to be full length, and doesn't need to be flush with bottom of existing joists--can be vertically offset) anywhere you plan to walk, and put a catwalk after blowing in the insulation.
Comment: @Huesmann, crossframing (with blocking in every other opening) would be significantly cheaper and easier than sistering.
Comment: @SteveSh given how rarely one needs to go, and how much better a job of blocking air leaks cellulose does than batts, I don't consider a little snow shovel / rake relocation of cellulose a big deal. And it doesn't make me itch.