Sucrose skeletal formula - missing Carbon and Hydrogen

Question: I was reading the Wikipedia article about Sucrose, when I noticed that the skeletal formula was missing some $\ce{C}$ and $\ce{H}$ atoms. The chemical formula being $\ce{C12H22O11}$, I counted the $11$ Oxygen parts. But there seem to be only $3$ $\ce{C}$ atoms and $14\, \ce{H}$ atoms, if I counted correctly. My chemistry lessons date back about $15$ years, so I'd like to understand where the missing carbon and oxygen is hidden within the skeletal formula.
Comment: Every point in the bond is a carbon atom.. H is just added to satisfy valency after.. You could read up on the bond-line formula of a compound..
Comment: [This Libretexts page](https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Map%3A_Organic_Chemistry_(Wade)/01%3A_Introduction_and_Review/1.08%3A_Structural_Formulas_-_Lewis%2C_Kekule%2C_Bond-line%2C_Condensed%2C_and_Perspective) should help.
Comment: Ah, that makes sense. And the "bold" parts are `CH` ions then? That would account for the missing Hydrogen.
Comment: Any formula is a condensed knowledge that must be unpacked by applying certain rules. For example, the mathematical formula for "eleven" is 11. One who does not know the rules might wonder why there are only two sticks and not eleven. Same thing here.
Answer: Since your chemistry lessons date back about 15 years, I'd loke to refreash your organic chemistry knowledge. You may need to be aware that carbon can make maximum if 4 single bonds. Therefore, when you have a line structure of organic compound like sucrose (see below), keep in mind that an each corner represent a carbon atom and appropriate hydrogen atoms, which are not shown. For example, if a corner contains only three bonds (as shown in most of sucrose molecule), then the forth bond is $\ce{C-H}$ bond:

I have put those $\ce{C-H}$ at each corner, which are representing them. However, the anomeric corner of fructose molecule already has 4 bonds. Therefore, that corner represents only $\ce{C}$ as indicated in turquoise color. Therefore, the molecular formula of sucrose can be counted as $\ce{C12H22O11}$.


Partitioning scheme for Ubuntu

Question: My laptop has a 240 GB SSD. Right now I'm using Windows. But I'm planning to clean install Ubuntu (Not dual boot). So I need help with the partitioning. Can anyone please suggest me a partition scheme for 240 GB SSD? My laptop has 8 GB RAM.
Comment: Unless you have a specific *use-case*, I'd use the default which is a single partition (and uEFI partition if required for your *unstated* release). Single partition(s) are easier esp. for encrypted installs; though if no encryption is used; I may also separate /home but that's assuming desktop install (you didn't specify) and use a *swap file* (not partition) assuming the *unstated* release defaults to it.  My choice would depend on details you've not provided.  (*simplest is usually best unless you have specific needs*)
Comment: The best partition scheme is the one that works for you. As an opinion, do not over-partiton. Unless you have a particular need for multiple partitions, don't make extra partitions. Ubuntu works perfectly fine installed to a single partition and you don't have to deal with a headache later on because you are running out of space on some partition. Making extra partitions doesn't improve the performance of Ubuntu.  For organization, use folders.
Comment: I'd recommend 25GB for `/`, 8GB for swap, and the rest for `/home`. This will let you upgrade your system without affecting user files.
Answer: So I installed Ubuntu finally some days ago and here is how I partitioned.

50 GB for root
8 GB swap
500 MB for boot
500 MB efi
and the rest is for home

Hope it helps.
Comment: Perhaps the file system types will also help!

Partitioning scheme for Ubuntu


Alignment buttons greyed out in Sketch

Question: I am teaching remotely sketch, but one of my mentees says that he cant use the alignment tools, they always appear greyed out even when he already selected multiple shapes. Any idea what is causing this? Have anybody experience something like this before?
Here is a screenshot of how it looks on his end.
Comment: I think you should contact [Sketch support](https://www.sketchapp.com/support/).
Answer: You did not create an artboard.I am not sure but try to create an artboard first.
for creating artboard, hit "A" button.

Alignment buttons greyed out in Sketch


Can I get the Rings of Blood Magic when I joined the Dawnguard?

Question: I finished the Dawnguard side of the quest, and now I'm wondering if I can still get the vampire power rings and amulets. Is that possible?
Answer: No. You can't get the quest to find the rings until you finish The Bloodstone Chalice; if you sided with the Dawnguard instead of taking Harkon's gift, you don't get The Bloodstone Chalice quest. The rings spawn semi-randomly when you accept the quest, so they won't be in the world for you to otherwise find.
The same is true of the quest to get the amulets.
Besides, the gentleman who gives you the quest will either be inaccessible (as the castle got locked behind you), dead (if you killed him later) or at least hostile towards you.
The rings are xx00e7fe and xx00e7fd (see here for the meaning of xx) if you want to cheat yourself a pair though. The amulets are xx00f4d5 and xx0068ae.


Some examples for Q-Gorenstein variety and Gorenstein variety.

Question: Could you give us an variety X which is Q-Gorenstein variety, but this variety is not Gorenstein variety?
What is the canonical divisor K_X on X? How can we compute its canonical divisor?
Could you give us an variety which is not Gorenstein variety?
What is the canonical divisor K_X on X? How can we compute its canonical divisor?
Comment: Just to quickly answer the other question.  The canonical divisor $K_X$ on a normal variety $X$ is *any* divisor $D$ such that if $U \subseteq X$ is the regular locus, then $$O_U(D|_U) \cong \Omega_{U/k}^{\dim X}.$$

One common way to compute a canonical divisor is by adjunction.  For example, if $X \subseteq Y$ is a normal hypersurface in a normal variety $Y$, and we know the canonical divisor on $Y$, then $$(K_Y + X)|_X = K_X.$$

Alternately, for any $X$ of dimension $d$ in $\mathbb{P^n}$, then $$O_X(K_X) \cong \mathcal{E}xt^{n-d}(O_X, O_{\mathbb{P}^n}(-n-1)).$$
Answer: Let me give a couple more examples to complement what J.C.Ottem already said.
First I'll point out a couple discrepancies in terminology for a normal variety:
Gorenstein:  This means that both $K_X$ is Cartier and $X$ is Cohen-Macaulay.
$Q$-Gorenstein:  This means that $nK_X$ is Cartier for some integer $n > 0$.
Quasi-Gorenstein (or $1$-Gorenstein): This means that $K_X$ is Cartier but that $X$ is not necessarily Cohen-Macaulay.
In particular, $Q$-Gorenstein does not usually imply Cohen-Macaulay (because of this a lot of people don't like the terminology, notably János Kollár).  On the other hand, some people like to require the Cohen-Macaulay condition in their $Q$-Gorenstein definition (adding to the confusion).  It would also be "reasonable" to require that some canonical cover of $X$ is Cohen-Macaulay!
Ok, let me at least state the general rule for when a cone (or rather a section ring) is $Q$-Gorenstein or Gorenstein.
First note that because $S$ is graded, a module is free of rank one if and only if it is isomorphic to $S$ itself (up to a shift in grading).
Suppose that $X$ is a smooth (or even Gorenstein) projective algebraic variety over a field $k$ and suppose that $L$ is an ample line divisor.  Form the ring:
$$
S = \bigoplus_{k \in \mathbb{Z}} O_X(kL)
$$
and let $m = S_+$ denote the irrelevant ideal.
Also form the $S$-module
$$
\omega_S = \bigoplus_{k \in \mathbb{Z}} (\omega_X \otimes O_X(kL))
$$
I claim that $\omega_S$ is the canonical module of $S$.  This is actually pretty easy to see, $S$ is always normal so $\omega_S$ is determined on $U = \text{Spec} S \setminus m$.
Therefore since $f : U \to X$ is a $\mathbb{A}^1$-bundle it follows that $\omega_U$ is just $f^* \omega_X$ which it is easy to see coincides with $\omega_X|_U$.
Then
Theorem (quasi-Gorenstein): The ring $S$ is quasi-Gorenstein if and only if $K_X \sim nL$ for some integer $n$ (possibly $n = 0$).
The proof idea is as follows.  Since $K_X \sim nL$, it follows that $\omega_S$ is just $S$ shifted over by $n$.  But that's a free module.  Conversely, if $\omega_S$ is a free module, since $S$ is graded, it must be a shift of $S$.
Theorem ($Q$-Gorenstein): $S$ is $Q$-Gorenstein if and only if $mK_X \sim nL$ for some integers $n$ and $m \neq 0$.
The proof idea is similar, it follows from the same sorts of arguments as above that $$O_{\text{Spec} S}(mK_S) = \omega_S^{(m)} = \bigoplus_{k \in \mathbb{Z}} O_{X}(kL + mK_S).$$  Therefore for this to be free, we need exactly $mK_S = nL$ for some integer $n$.
Theorem (Cohen-Macaulay): Finally $S$ is Cohen-Macaulay if and only if $H^i(X, O_X(kL)) = 0$ for all $\dim X > i > 0$ and all $k \in \mathbb{Z}$.
Note that the points away from the origin are Cohen-Macaulay since $X$ was smooth (or at least Gorenstein $\Rightarrow$ Cohen-Macaulay).  The point is then that $[H^{i+1}_m(S)]_k = H^i(X, O_X(kL))$ where $[\bullet]_k$ is the $k$th graded piece of the module.  This follows from computations in Cech cohomology.
The upshot:
This gives us lots of examples of varieties that are $Q$-Gorenstein or not.
Fano: If $X$ is Fano (meaning $-K_X$ is ample) and we take $L = -K_X$, then $S$ is certainly quasi-Gorenstein.  On the other hand, if we take $L = -mK_X$, then $mK_X = (-1)L$, $S$ is $Q$-Gorenstein.
Now let's suppose we are in characteristic zero and that $X$ is smooth.  If $k > 0$, we have $H^i(X, O_X(kL)) = H^i(X, O_X(K_X + (m-1)K_X + (k-1)L) = 0$ by Kodaira vanishing.  If $k < 0$, by Serre-duality, $H^i(X, O_X(kL)) = H^{\dim X - i}(X, O_X(K_X - kmL)) = 0$ by Serre vanishing.  On the other hand for $k = 0$, $H^{i}(X, O_X) = H^i(X, O_X(K_X - K_X)) = 0$ by Kodaira vanishing.  Thus $S$ is Cohen-Macaulay.
Calabi-Yau: If $X$ is Calabi-Yau (meaning $K_X = 0$) and we choose any ample $L$, then $S$ is quasi-Gorenstein.  It may not be that $X$ is NOT Gorenstein though, it depends on the vanishing of $H^i(X, O_X(kL))$.  For example, an Abelian surface has $H^1(X, O_X) \neq 0$.
Others: If $K_X$ is neither ample nor anti-ample, nor $Q$-trivial, then you are out of luck.  The cone will never be $Q$-Gorenstein.
Comment: is there a relation between gorenstein and having quotient singularities?
Comment: No, there are non-quotient singularities that are Gorenstein (any hypersurface singularity is Gorenstein).  There are quotient singularities that are not Gorenstien, for example $k[x^3, x^2y, xy^2, y^3]$.  Normal finite quotient singularities are always Cohen-Macaulay and $Q$-Gorenstein though.
Comment: thanks for the quick reply! where would I go about learning the normal finite case for example?
Comment: For the Cohen-Macaulay bit, this follows since the ring is a direct summand of the ring it is the invariants of.  There is a paper of Hochster and J.~Roberts that does this.  In fact, Boutot's theorem actually says that the singularity is *rational*, which amoung other things is Cohen-Macaulay.  This stuff works for reductive groups.
$$\text{ }$$
For the $Q$-Gorenstein bit, see for example Lemma 5.16 in Kollár-Mori, *Birational geometry of algebraic varieties*.
Answer: Cones are usually a good source of examples when it comes to questions like these. In your case, let $Y\subset \mathbb{P}^5$ be the Veronese embedding of $\mathbb{P}^2$ and let $X\subset \mathbb{P}^6$ be the projective cone of $Y$. Then $X$ is a normal non-Gorenstein variety which is not Gorenstein. Indeed, Let $L\subset Y$ be the image of a line in $\mathbb{P}^2$ and let $D$ be the Weil divisor given by the cone over $L$. Let $H$ be the generator of $Pic(X)$, that is, the hyperplane section from the embedding in $\mathbb{P}^5$. Then $-K_X=3D$ is not Cartier (as you can see by blowing up the vertex of the node and use the adjunction formula). But $2K_X$ is certainly Cartier as $2K_X\sim -6D\sim -2H$.
Answer: It is also quite easy to generate a lot of examples with toric geometry. We have next characterization:
Let $\Sigma$ be a fan in a lattice $N$ and $M = N^*$ dual lattice. Then

$X_{\Sigma}$ is $\mathbb Q$-Gorenstein iff for each cone $\sigma \in \Sigma$ generated by $n_1,...,n_r \in N$ there is $m \in M \otimes \mathbb Q$ such that $(n_i,m) = 1$ for every  $i=1,...,r$
$X_{\Sigma}$ is Gorenstein iff for each cone $\sigma \in \Sigma$ generated by $n_1,...,n_r \in N$ there is $m \in M$ such that $(n_i,m) = 1$ for every  $i=1,...,r$

For example for a complete fan with generators $(-1,-2),(1,0),(0,1)$ in $\mathbb Z^2$ we can check that the only solution of system $-1x-2y=1, x=1$ is $(1,-\frac{1}{2})$. So $X_{\Sigma}$ is not Gorenstein, but $\mathbb Q$-Gorenstein. In fact, $X_{\Sigma} \cong \mathbb P(1,1,2)$ in this case.
Comment: +1 WPPs were the first example that came to mind. It should be straightforward to characterize which ones specifically satisfy the desired condition.


How do I install wunderlist?

Question: Wunderlist is a todo list, and apparently they now have Linux support. How do I install it?
Comment: Unfortunately, they seem to have dropped their linux support for the native client. Too bad I've got a little bit late for the party...
Comment: The solution to make it work with 11.10 is here:
http://support.wunderlist.com/customer/portal/questions/63885-ubuntu-11-1-installation-?new=63885 And it works, indeed!
Answer: There are two ways of doing this.
You can install Wunderlist via the Ubuntu Software Center. Open the Ubuntu Software Center, then search for Wunderlist - you can then install it from there. However, at time of writing, this will not work in 11.10, due to some incompatibility issues.
However, you can try the manual way outlined below.
First, download Wunderlist from their website.
Now, you need to unpack the .tgz that it comes in - run the following:
tar  xvzf ./Downloads/wunderlist*.tgz
Then you need to open the Wunderlist file - open up Nautilus (or your file browser of choice) and navigate to the ~/Wunderlist-<version number> folder. In there you'll find a file named Wunderlist - double click it, and Wunderlist will open up - login and you're ready to go.
Comment: @Balthazar You should report that as a bug [here](http://support.wunderlist.com/)
Comment: When I do this I get a window with license information and when I click run it crashes. I can only start the app by typing "sudo ./Wunderlist" I have Wunderlist-1.2.4 if that helps.
Comment: This answer is no longer valid.
Answer: Instructions for Ubuntu 12.04 and 11.10 are here
How To Install Wunderlist In Ubuntu 12.10, 12.04 Or 11.10 ~ Web Upd8: Ubuntu / Linux blog
Edit Nov 2012:
Still no luck but you may use Fogger to get Wunderlist, web version, as a webapp in Ubuntu. Just install Fogger via Software Center, open Dash, enter 'Fogger' in it, 'create new' and follow the instructions. Courtesy of OMG Ubuntu!
Fogger Brings To-Do App Wunderlist back to Ubuntu 12.04 LTS
Please note that in 12.10 you don't have to add any PPA's. Just follow my instructions above.
Comment: I've just installed Wunderlist as per instructions I linked to but it simply won't start. I get the welcome window (Wunderlist Installer) with Cancel and Run buttons. I press Run and it won't start. It's visible in Dash (program icon). Launching either from dash or by terminal command wunderlist or even by cd /opt/Wunderlist-1.2.4 and then Wunderlist returns 'Wunderlist: command not found' error. Any hints?
Comment: I've added a post in the official wunderlist support section but so far no answers http://support.wunderlist.com/customer/en/portal/questions/342364-ubuntu-12-4-x64-linux-installation?new=342364
Answer: As far as I know currently there is no official Wunderlist app for Linux.
An alternative is wunderlistux which is basically a non official wunderlist app for linux
To install it you just have to download the last release from here:
https://github.com/edipox/wunderlistux/releases
You can use the AppImage which allows you to try the app without installing it but also allows you to install the app if you want. Or you can download the install script and run it as sudo:
sudo ./install.sh
More information can be found here: https://github.com/edipox/wunderlistux
Hope you like it!
Comment: Welcome to Ask Ubuntu! Perhaps you could expand this answer to explain how your wrapper will assist the OP in installing Wunderlist in Ubuntu.
Comment: Thanks @ElderGeek ! I've updated my answer to explain it
Answer: Call
sudo ln -s /usr/lib/x86_64-linux-gnu/libffi.so.6 /usr/lib/x86_64-linux-gnu/libffi.so.5

Comment: 'ln: failed to create symbolic link `/usr/lib/x86_64-linux-gnu/libffi.so.5': File exists'

How do I install wunderlist?


Is the attainment of natural wisdom exclusive to Buddhism?

Question: Regardless of the medium, or the path, do you know of any other traditions, or religions, or ways to attain wisdom? Wisdom as it's known in buddhist tradition: Seeing things as they are.
Comment: By asking about "other traditions or religions" wouldn't this be off topic for Buddhism.SE?
Comment: Panna, wisdom, in buddhism, is insight into reality: impermanence, suffering, and non-self. So I believe we can answer this question. Yes, there are other religions or traditions which may teach true wisdom. But they will all, regardless of their name, teach the same thing as Buddhism. Namely, the nature of reality as suffering, the cause of suffering, and the path leading to the cessation of suffering.
Comment: If we equate "true  wisdom" with nibbana, I think parinibbana sutta has an interesting answer: "In whatsoever Dhamma and Discipline, Subhadda, there is not found the Noble Eightfold Path, neither is there found a true ascetic of the first, second, third, or fourth degree of saintliness. But in whatsoever Dhamma and Discipline there is found the Noble Eightfold Path, there is found a true ascetic of the first, second, third, and fourth degrees of saintliness."
Comment: @Wanderer. When asking about other "traditions" are you then talking about traditions/schools within Buddhism?
Comment: @Robin111 actually this question addresses Buddhisn directly.
Answer: Dhamma isn't exclusive to Buddhism. As the story goes, wherever there are apple trees, there are apples; but one can't expect to find apples where there aren't apple trees. Likewise, can't expect to find wisdom teaching where wisdom is not being properly taught.

While sitting on one side the wanderer Subhadda said this to the Gracious One: "Those ascetics and brahmins, dear Gotama, who have a community, a group, who teach a group, well-known, famous, religious founders, agreed upon as good for the people, such as: Pūraṇa Kassapa, Makkhali Gosāla, Ajita Kesakambala, Pakudha Kaccāyana, Sañjaya Belaṭṭhaputta, Nigaṇṭha Nāṭaputta, have they all understood, according to their own avowal? Have they all not understood? Or, have some understood? Or, have some not understood?"
"Enough, Subhadda, stop this: 'Have they all understood, according to their own avowal? Have they all not understood? Or, have some understood? Or, have some not understood?' I will teach the Teaching to you, Subhadda, listen to it, apply your mind well, and I will speak."
"Very well, reverend Sir," the wanderer Subhadda replied to the Gracious One, and the Gracious One said this: "Wherever, Subhadda, the Noble Eightfold Path is not found in a Teaching and Discipline there a true ascetic is not found, there a second true ascetic is not found, there a third true ascetic is not found, there a fourth true ascetic is not found.
But wherever, Subhadda, the Noble Eightfold Path is found in a Teaching and Discipline there a true ascetic is found, there a second true ascetic is found, there a third true ascetic is found, there a fourth true ascetic is found.
-- Mahāparinibbāna sutta, DN 16
Answer: Of course not!
In buddhism there are beings called paccekabuddhas, which are beings who attain enlightenment in a period where the dharma is not available in this world. Since this is possible, it's also possible that a practitioner of another tradition attains enlightenment, or at least some of the stages of enlightenment.
But when the Buddha said, in the Satipatthana Sutta that "This is the direct path", also translated as "This is the only path", he meant that any person who wants to attain enlightenment has to have direct knowledge of what he was teaching in that sutta. In short, that the body, sensations, mind states and mental objects are impermanent, unsatisfactory and are not-self.
What this means is that truth is truth, it's not buddhist truth. Whoever knows truth, he is enlightened. But he has to see the truth anyway, because there is no other way to liberation aside from directly knowing the truth.
Comment: "*You shall know the truth, and the truth shall set you free.*" John 8:32
Comment: Indeed. Perhaps we shouldn't be too naive and think all religions are the same. But any person who is sincere, resolute and disciplined in search of the truth will be traveling mostly in the right direction. Different religions, or even different sects of buddhism may send us in somewhat different directions when we begin, but the commited search for truth is the core, imo. And these commited seekers may attain stages of enlightenment irrespective of their religion.
Answer: Nonduality is part of all religions and cultures, and exists back through time, as best I can tell, so it is "naturally" part of the human experience. It does not depend on a deity or scriptures or dogma, or any other artifact or particular: it depends only on increasing self-development and self-awareness.
That there are as many descriptions of it as describers, and differing opinions on how to achieve it, should not deter anyone. "You are unique, just like everyone else." Self Inquiry is the path to Nonduality (along with anything else that you personally find helpful), and is increasingly well-known and practiced by peer-led groups around the world. I co-lead one where I live.
Gone, Gone, Gone Beyond, Gone Completely Beyond, Wisdom, So Be It! (The Mantra of Prajnaparamita - Supreme Wisdom - from The Heart Sutra - which explicitly disavows and overturns all of the basic tenets of Buddhism.)
Answer: Is the attainment of natural wisdom exclusive to Buddhism?
No.
Do you know other traditions, or religions or ways to attain wisdom?
Yes.
Buddhist wisdom is not an enterprise owned by any cultural stream.
All spiritual attainments are beyond name and form.
Watching your mind (which includes the Four Foundations of Mindfulness) is recommended in almost every religious school and any self-developmental seminar worth a penny.
I could go into a long tirade as to why spiritual self-development is similar across all religions but there are a limitless explanation on the phenomena of shared experiences (kundalini, chi, visions, emptiness, heat, sweating, etc.).
I cannot do this topic justice though because there is a huge burden of proof that is already there.
So where do I recommend you look to get a detailed answer to both of your questions?

Read Spiritual Paths and Their Meditation Techniques ($)
Read How to Measure and Deepen Your Spiritual Realization - A Short Multi-disciplinary Course on Evaluating and Elevating Your Meditation Progress and Spiritual Experiences ($$$)
Read all the articles here. There are many guidances of other non-Buddhist techniques you may apply to grow spiritually. (free)

--
Now, I am assuming that you did look into explanations there above. Now are full of understanding of the 5 Stages of the Spiritual Path that are common to all cultivation schools. Now you know for sure that the spiritual path is something beyond any prayer to any deity... it is developing Pure Presence and cultivating other features of Being-As-Is.
Now, I would like to tell you that despite the fact that various cultural streams have many of the same features as Buddhism... and even similar or even equivalent practices... (Early) Buddhism is still better.
It is the most organized, systematic method available.
Buddhism, especially Theravadin Buddhism, is the "only" direct path. It is what the Buddha first spoke after all...! It contains within it the bare essentials to practice -- the "extras" are supportive practices like to improve your morality practice Brahmavihara.
Although it may seem that some sects in some religions are exclusive, all the various methods within Buddhism and in all religions--fall under the 8/9 samadhi/dhyana/jhana that our Lord Buddha experimented with and shared.
"The Surangama Sutra" or the more adaptable "Twenty-Five Doors to Meditation - A Handbook to Entering Samadhi" both expand and explain this in a practical way.
Comment: Sorry to be off-topic: I noticed you removed the [tag:nonduality] tag which @nocomprende added to the question. Though I don't know what "nonduality" is exactly, nor "natural wisdom", if you have time would you mind posting on [this meta-topic](http://meta.buddhism.stackexchange.com/q/1599/254) to explain why you removed that tag, ideally clarify or come to consensus with nocomprende about when and where that tag should or shouldn't be used?
Answer: A well known Vipassana meditation teacher, Mr. S.N. Goenka always refers to the Dharma (the truth or seeing things as they are) in a non denominational way.

Dharma is not Hindu nor Buddhist,
  not Sikh, Muslim, nor Jain;
  Dharma is purity of heart,
  peace, happiness, serenity.
  —Hindi doha of S. N. Goenka
Two thousand years ago in India, there were two distinct traditions. One tradition gave importance to the purity of Dharma. The other gave importance to sectarian rites, rituals, religious ceremonies, external appearances, and so on. In those days the tradition of pure Dharma was quite strong, but slowly it became weaker and weaker, and eventually vanished from India. What was left had no trace of pure Dharma. It is very unfortunate that we have lost Dharma. When one speaks of Dharma in today's India, the question that arises in the audience's mind is: "Which Dharma? Hindu-dharma, Buddhist-dharma, Jain-dharma, Christian-dharma, Muslim-dharma, Sikh-dharma, Parsi-dharma, or Jewish-dharma? Which Dharma?"
It is a great pity that we have totally forgotten pure Dharma. How can Dharma be Hindu, Muslim, Christian, Jain, Parsi, or Sikh? This is impossible. If Dharma is pure Dharma, it is universal. It cannot be sectarian. Sectarian rites and rituals differ from one sect to another. The so-called "Hindu-dharma" has its own rites, rituals and religious ceromonies; its own beliefs, dogmas, and philosophies; and its own external appearances, and disciplines, such as fasting. It is the same with the Muslim-dharma, Christian-dharma, Sikh-dharma, and so on. But Dharma has nothing to do with all these. Sectarianism is divisive. Dharma is universal: it unites. Source: The Gracious Flow of Dharma - by S.N.Goenka

Mr. Goenka's meditation centers around the world teach insight meditation in a completely non religious setting. Rules include not being able to bring religious items or continue with spiritual practices while you are there.

During the course it is absolutely essential that all forms of prayer, worship, or religious ceremony — fasting, burning incense, counting beads, reciting mantras, singing and dancing, etc. — be discontinued. All other meditation techniques and healing or spiritual practices should also be suspended. This is not to condemn any other technique or practice, but to give a fair trial to the technique of Vipassana in its purity.

I believe this to be an example of a practice of learning to attain wisdom, as it's known in the Buddhist tradition, outside of Buddhism.


How much percentage of outliers are allowed in a data

Question: I am buliding a machine learning model with logistic regression. I am dealing with blood transfusion data set. In which there is a feature,Total_volume, I found that there is more than 5% of outliers present.Should I handle this? Or I keep this data as it is? Bacauase more than 5% data may contain some patterns.
Comment: How did you find these "outliers"?
Comment: The answer to this questions, among other things, is highly domain dependent. Is it normal to have such values in blood transfusion, could it just be an anamoly ?
Comment: I drew boxplot for visualizing the outliers.
Answer: I'm assuming you've classified outliers using some rule, like over 3 standard deviations or something?
Look at a histogram of your data; is it normally distributed with outliers? Or is it non normally distributed? If you run normality tests on data that just isn't normal (e.g. reaction time, or income) then you will think you have lots of outliers when you don't.
If your data isn't normally distributed there are lots of ways to address it, including transforming the data (e.g. a log transform) or by....ignoring it!
Also, if the 'outliers' were definitely mistaken values, perhaps it's ok to remove them, but if they are normal values, remove them with caution, because your model will still encounter these individuals when it is deployed, so removing them now could mean worse performance in production.
Answer: I have worked for Bank and e commerce . The outliers can be set at as low as .1% or as high as 20%.

Plot a scatter curve or box plot
Start with hypothesis that 0% are outliers
Determine how many points you are excluding from  dataset by removing next 1%.

If the exclusion is significant, then that is your outliers %


What ore can you create/refurbish funiture with in Animal Crossing New Leaf?

Question: In ACNL I have got a couple of pieces of the gold funiture series which I made by bringing Cyrus a gold ore and 10,000 bells. Is this only possible to do with gold ore? Also is it possible to refurbish an item of funiture with other types of ore? For instance make a normal table an emerald table.
Answer: All ore can create customized furniture (this is it's primary function), however only very few furniture sets or items can be customized. The Animal Crossing Wikia site has a full list
Answer: You need three types of the same ore and 10,000 bells and one piece of furniture.
Then talk to Cyrus and he will ask for the stuff give him the ore and he will take everything.
Then wait for 30 minutes and go back to get the item.


Bulk sensors update in Azure Digital Twins

Question: As Azure Digital Twins user, I'd like to be able to assign multiple sensors to equipment and unlink multiple sensors from equipment in one go and if there some error all changes should be rollback so data won't be broken. ADT API has an endpoint to single sensor update PATCH /api/v1.0/sensors/{id}, but I need to do it in one transaction. How I can do it?
Comment: Do I understand correctly that you are trying to move multiple sensors to a different device in one request? That seems to be impossible using the REST API. What kind of errors are you trying to avoid?
Comment: @MatthijsvanderVeer f.e. I need to assign 100 sensors to equipment or unlink. I don't want to do 100 requests. I want to do it in one request and rollback if some sensor was not updated. Otherwise if f.e. 10 sensors were updated (f.e. changed equipment) and others 90 sensors catch some error with update and stiil assign to old equipment - there will be mess in data.
Comment: This doesn't seem to be supported by the API. It is possible to create multiple sensors in one request when you create a new device (POST), so I was hoping the PUT request allowed the same, but alas.
Answer: Do you use any code to support your component?
Like C# environment or something like that ?
You could just multiply your request with some code, but i really don't think you could do that kind of request with the preview version of ADT right now.
Maybe wait for the GA version of ADT.


Changing the width of begin center

Question:
I am writing my Master's thesis and was wondering how I can write the introduction to every section like this. I have already gone through the other posts where they have discussed about how one can change the width of the 'begin center' part, but I was unable to use any of those techniques myself. Please let me know if you guys know some easier method. Thanks.
Comment: That is not centered text. It is text with different margins. It is basically what the `abstract` env does. In order to provide mode help we need to know what class and packages you are using (perhaps some of them already provide something usable)
Answer: I think you can try adjustbox.
\documentclass{article}
\usepackage{adjustbox}
\usepackage{lipsum}

\begin{document}

\begin{adjustbox}{minipage=.7\textwidth,margin=0pt \smallskipamount,center}
    \itshape\lipsum[1]
\end{adjustbox}
\vspace{2em}

\lipsum[2]

\end{document}

This answer is adapted from here.
Answer: I can reproduce the layout used in the screenshot you posted by employing the amsart document class, using \section and \subsection directives, and employing a quotation environment. The quotation environment increases the widths of both the left and right margins or, put differently, reduces the value of \textwidth.
I would definitely not use a center environment, as you're not looking to center-set each line, are you?

\documentclass{amsart}
\usepackage{lipsum} % filler text

\begin{document}
\setcounter{section}{8} % just for this example

\section{Intersection theory}

\begin{quotation}
\slshape % Employ slanted-roman font shape. If you prefer
         % "regular" italics, use either '\itshape'  or '\em'.

\lipsum[2] % first para of filler text

\lipsum[2] % second para of filler text
\end{quotation}

\subsection{Chow groups}

Having discussed the basics of scheme theory, we will now start
with the foundations of intersection theory. The idea of
intersection theory is the same as that of homology in \dots
\end{document}

Comment: This seems really easy, but when I tried it, there was a huge gap between the end quotation and the start of the subsection.
Comment: @RioDutta - So far, you have provided *exactly zero information* about your document setup -- other than the fact that you employ LaTeX to compile it. My example code managed to replicate the overall look of screenshot you provided rather well. However, your comment would make it appear that this "feat" is actually of little or no practical relevance to you. Hence, do please start to provide some relevant information about your document setup, starting with the document class you employ.
Comment: I am really sorry for providing such little information. As I have checked, this code seems to work on article class, but leaves the big gap in book class on Overleaf. Do you have any suggestions for the book class?
Comment: @RioDutta -- You still haven't provided much usable information about your document. Hence, all I can suggest you try is (a) shortening or lengthening the introduction, i.e., the material that's place in the `quotation` environment, and (b) issuing the command `\raggedbottom` in the preamble.

Changing the width of begin center


How does paying extra on my mortgage affect my amortization schedule?

Question: I am a first time home buyer and have some spare cash after my home purchase to pay forward quite a bit of money (cash was not available during actual purchase, so, no, I could not have put it towards the downpayment). I just want to make sure I understand precisely what happens with my amortization schedule if I pay extra/ahead of time. My mortgage is $300k at 3.7% interest (30 year fixed). Here is the first few months in the schedule:
My question is, let's say I pay both November and December's principal in November (ie paying $913.10 in principal + November's $925.00 interest). Does my new schedule look like this?
The key question being that the $923.59 interest from the original schedule's December just completely disappears? (Perhaps the resulting principal/interest in the post-November months would change since technically the balance is now lower... but I'm not fussed over the specific mathematics on that point). I am expressly asking does the $923.59 interest from December permanently go away?. Phrased more generally, does paying month x,y,z's principal forward permanently remove month x,y,z's interest (where x,y,z are months that are not the current month)?
Answer: Interest does not "disappear", but it is reduced in proportion to your outstanding principal balance.
Interest accrued in a pay period (month) = Principal balance * Interest rate (monthly)
It sounds like this is what you probably meant. In your example, Dec-19 interest is reduced to what Jan-20 interest would have been without the extra payment.
Answer: People already answered, but the point is you have a flaw in your thinking. December interest is not interest on december's principal payment amount. You're paying interest on $300k (which is why it's so much), not on $450 (which would be 200% interest per month), your december interest is reduced by about 0.3% (3.7%/12) of $450 (the additional principal you're paying) which is about $1.50
Comment: Your answer assumes OP misunderstands. I think he just wrote the line in an ambiguous way. From his comments on my answer, I think he knows what he's doing.
Answer: If you prepay your mortgage you reduce the principal balance, reducing the interest due next month and every month forward.  If you prepay $1000 on your mortgage, the interest next month will be reduced by 1000*3.7%/12=3.08  You will still make the same payment, but an additional 3.083 will be credited toward principal.  The month after that the principal will be 1003.08 lower than shown on the original schedule, the interest will be reduced by 1003.08*3.7%/12=3.09 and so on.  If you sell the house, the payoff of the mortgage will be reduced by the reduction in principal and you will get the money back.  If you don't sell the house, the last payments are deleted from the loan and you get your money back that way.
You can create a new amortization schedule in a spreadsheet.  A good way to think about it is that you are depositing the $1000 in a savings account at 3.7%.  The interest is taxable if you itemize deductions, nontaxable if you do not.  If you prepay $1000 after one year, it compounds up to 1000(1+3.7%/12)^(29*12)=2919.32 at the end of the loan, so you will save two payments and a little bit of a third.  You get your money back when you sell the house or pay off the mortgage.  If that is an attractive investment to you, go ahead and prepay the mortgage.  I would point out that this is the cheapest money you are likely to borrow (except for promotional loans on things you buy).
If you prepay next month's principal, you will remove one payment from the end of the loan. If you prepay the next three months principal, you take three payments off the end.
Comment: All true, but, for whatever reason, OP was focussed on the process of moving ahead a month at a time. But your math and comments are absolutely right.
Comment: @JoeTaxpayer : good point. I added some about that.
Comment: I've seen mortgages where early payments only pays off interest and doesn't actually change the amount of interest you pay.
Answer: Yes. One 'trick' to paying your mortgage in an accelerated fashion is to use the amortization schedule, and pay 'next month's principal. That puts you a month ahead on the schedule. Put another way, if you math it, take that principal, and inflate it by applying the interest rate over the time til the current last payment, you'll see they match up. i.e. 1.037^30*457.25 = 1359.92 (close enough?)
To be clear, when you pay one month principal ahead, you literally move that extra month along on your amortization table.
Comment: Yes, but that's another question, one discussed here many times.
Comment: Please tell me if this follow-up statement is true or not: Since the amount I am saving on each additional principle payment x is basically x*(1+r)^(years), it is inadvisable to do since this r < .08, which is a general estimation of the return I would get for the same x in the stock market. In plain words, the money I save by paying forward $x is less than the money I would earn by investing $x into the stock market (3.625 vs ~8). Is that a good way to look at it?
Answer: The interest payment does not "go away", but the amount you have to pay will be reduced. Each month, the amount of interest accrued is based on the remaining balance; a smaller balance means less interest.
You can calculate a new row in the table/schedule the following way:

Interest = 0.003083 * previous balance (result of previous payment)
Payment = amount planned for payment (make sure this is at least the minimum due expected by your lender)
Principal paid = payment - interest
Remaining balance = previous balance - principal paid

Here, 0.003083 is an approximation of the monthly interest rate (3.7% divided by 12 months).
Answer: Others may have made this clear already, but it's an important point: Distinguish between prepaying and paying additional principal.
In the US, the default is often that additional money sent to the bank is just a deposit to be held against future months' payments. As such, they certainly reduce your risk of missing a payment, but do not actually shorten or reduce the cost of the loan.
If your loan permits additional payments against the principal without penalties (not all do), and if you have made it sufficiently clear that this is your intent, that does actually reduce how much you owe and result in your paying off the loan earlier and paying less total interest. You can calculate it using the same kind of amortization formulas as before; if you like you can think of it as refinancing at the same rate and monthly payment but with that much less borrowed, solving for how long the loan will run and what it's total cost will be.
In fact it isn't wholly uncommon for folks to take out, for example, a 30-year mortgage but to try to make the larger payments that would be due for a shorter time period, eg 15 years. That finishes paying off the loan in about 15, years at a cost not very different from  having gotten a 15-year loan at the same rate in the first place, while always giving them the option to pay less in a given month if cash flow is tight at the cost of moving the loan a step back toward the 30-year base version.
But, again, this requires that the terms of the loan let you pay down the principal this way, and that you make sure that every payment is clearly marked as being the loan payment plus additional money to pay down the principal. And it's a good idea to read your statements carefully to make sure they did what you requested rather than taking it as pre-deposit against future payments.
(Pre-deposit has its uses too, of course -- if you're going to be clout if the country for a while, it protects you from missing payments and being penalized for that. But it doesn't  actually reduce the cost or duration of the loan.)
If this sounds worth investigating, your bank's loan department can help you run the numbers to see how much difference it will make. Or you can play with amortization calculators and see the effect.
Answer: The answer will, in part, depend on the country you are in, in part, on the actual terms and conditions of your contract, and in part, on the regulatory structure the lender is required to operate under.
Having worked in this area for a segment of my life.  None of us can actually tell you the answer.
For a scheduled balance loan in the United States, yes, that is approximately how it would work if you paid precisely on the due date.  I can think of contracts where that would not be true though you no longer see them in much use in the United States.
The reason it may not work that way is that you may have a prepayment penalty, and you may not have the correct number of days in the calculation.  A prepayment penalty may reduce the amount that goes to the principal.  Also, some places have 360 day years and 30 day months while others have actual days in the actual year, and some have actual days in a 365 day year with no leap days.
I would tell you to see your loan officer, but they most likely have no idea.  Their job is sales.  They rarely have back-office knowledge because it isn't their job.
There are contracts, rare now in the United States, where the interest is precomputed so that you pay the same amount of interest no matter how much you pay or when you pay.  There is no such thing as a principal reduction in any ordinary sense.  Your original amortization schedule happens no matter what your behavior is.  If you had a precomputed contract, then if you were supposed to owe $1000 in interest in January 2020, then no matter what you do, except paying the loan off, you will owe $1,000 in interest in January.  Even you had paid the loan down to one penny; you would still owe $1000 in interest.
Get your contract, deed of trust or mortgage out and read them.  Get a printout of recent payments.  That will give you a hint as to how many days are being used in a month and in a year.  The best indicator is February.  If the actual number of days is used then it will be a low interest month.  If it is 30/360 it will behave differently.  Most U.S. states require precomputed contracts to be spelled out in Truth-In-Lending statement or consumer finance protection statement.  Prepayment penalties will be spelled out in multiple places.
Finally, there have existed, I am not sure if they still exist, contracts that do not permit prepayment.  Partial payments may go to the escrow account or sit out as an unapplied credit waiting for the rest of the money to complete a full payment amount.  The money would just sit there doing nothing until it accumulated enough to be a full payment.  Then it would be applied when that payment came due.
Outside the United States, there are a number of interest calculation structures that are not used, nor are they similar to those used in the United States.
Simple interest is almost never used in the United States and is banned in some jurisdictions for mortgages.
EDIT
One additional thing, separate out any principal reduction and clearly mark it principal reduction.  If you do not, it may be applied to something else.  I might pay it in person.
If I had any concerns, I would do a small principal reduction and see how it affected loan behavior.
From the bank's point of view, you signed a contract to pay 360 payments of a certain amount on a certain date.  Unless it says otherwise, you did not sign a contract allowing you to vary your behavior from the stated terms.
Comment: "From the bank's point of view, you signed a contract to pay 360 payments".  That's not true.


Schematic pins shifted over on Altium 16

Question: I am coming across an issue where Altium is shifting pin names to the left. When I updated from 15 to 16, I have noticed the issue come up. When generating the schematic from 16 to 17, the issues go away. No, I did not shift the pin names like that when creating the parts. Comparison between 16 and 17 preferences are basically the same. I have been using 17 to generate the schematic, however, I want to stick to 16 right now. Please look at the examples below. Does anyone have any idea what could be causing the issue?
Answer: Uncheck the "Render Text with GDI+"
Go to: DXP -> Preferences -> Schematic -> General
Should work;-)


How to completely replace Helvetica with San Francisco

Question: in iOS 9, the system font had changed from Helvetica to San Francisco. I love the change! However, it doesn't change it in pages in Safari. Is there a way to change it to San Francisco? Thanks!
Answer: You can't change fonts without jailbreaking. If your device is jailbroken, you can copy your preferred SFUI font family from /System/Library/Fonts/CoreUI/ over the top of each Helvetica font in /System/Library/Fonts/Core/.
Comment: How do you jailbreak? Is it a hard thing to do? What risks does it take?
Comment: @awe I would not recommend it to everyone. It's not 'hard' but you do need some knowledge of the workings of iOS. Risks can be mitigated if you have a backup and are willing to update iOS. If you really want to try and you acknowledge the risks, you are welcome to ask a completely separate question regarding the specific version of iOS you are trying to jailbreak and the device model on which you are attempting it.


Basic setup using Symfony 4 messenger, php-enqueue, AWS SQS, AWS SNS

Question: The goal is to be able to send messages using AWS SQS+SNS. This has been a struggle for a few days and I don't know how to make it work.
Symfony 4.2 has a new component, messenger that I wanted to use.  It is supposed to work with php-enqueue as a third party transport.  I am using that to connect to AWS SQS+SNS.
I can't find any documentation that puts it all together.  I see how php-enqueue connects to AWS, but the docs show the config in the code and not in the config yaml or .env files. That is a problem since I want Messenger/enqueue to handle the behind-the-scenes stuff.
I was able to make Symfony Messenger work without php-enqueue for local synchronous messages. But after that... Clearly I am not doing it right.  I was hoping someone might have a boilerplate for this configuration.
Here is where I am at. I am just trying to send a message using SQS.  I am getting an error:
Error executing "GetQueueUrl" on "https://sqs.us-west-2.amazonaws.com";
AWS HTTP error: Client error: `POST https://sqs.us-west-2.amazonaws.com`
resulted in a `400 Bad Request`

I tried many permutations of keys in the enqueue.yaml file but did not get it right. I used this for help but could not get it to work. https://enqueue.readthedocs.io/en/stable/bundle/config_reference/
->> Edit: I found that you can add the topic and queue names to the DSN. I no longer get the error and a topic is created, but the Queue is not. Now, the message bus is working, but synchronously and locally.  No message is sent to AWS.
These are the Composer libs I installed. I am sure that there are too many, but I kept trying to make it work.
"aws/aws-sdk-php": "^3.19",
"enqueue/amqp-lib": "^0.9.8",
"enqueue/enqueue-bundle": "^0.9.8",
"enqueue/messenger-adapter": "^0.2.2",
"enqueue/snsqs": "^0.9.0",
"guzzlehttp/guzzle": "^6.0",
"symfony/amqp-pack": "^1.0",
"symfony/messenger": "4.2.*",

This is my messenger.yaml
framework:
    messenger:
        transports:
            amqp: 'enqueue://default?topic[name]=testQ&queue[name]=testQ'
        routing:
            # Route your messages to the transports
             'App\Message\SmsMessage': amqp

This is enqueue.yaml
enqueue:
    default:
        transport:
            dsn: '%env(resolve:ENQUEUE_DSN)%'
        client:~

This is the entry in .env
###> enqueue/enqueue-bundle ###
ENQUEUE_DSN=snsqs::?key={key}&secret={secret}&region=us-west-2
###< enqueue/enqueue-bundle ###

This is the code in a controller to send a message:
public function index(MessageBusInterface $messageBus) {
    $message = new SmsMessage('This is so cool');
    $messageBus->dispatch($message);
    ...
}

Comment: Not yet.  Still working on it. Please, let me know if you do. Symfonycasts just released their idea using doctrine which I will give a try.  https://symfonycasts.com/screencast/messenger
Comment: Did you ever get this to work?
Answer: I had this same issue which i managed to fix.
This is my messenger.yaml config that's working with SQS
transports:
         sqs:
             dsn: enqueue://default?topic[name]=YOURTOPICNAME&queue[name]=YOURQUEUENAME&receiveTimeout=3

Hopefully this is of use to someone


Java and ASP.NET

Question: Please can anyone tell me the difference between JVM and MSIL?
Comment: See http://stackoverflow.com/questions/95163/differences-between-msil-and-java-bytecode
Answer: JVM is the Java Virtual Machine, the virtual machine on the Java platform which executes Java bytecode.
MSIL is the Microsoft Intermediate Language, which is currently called the Common Intermediate Language (CIL), are the "lowest-level human readable" instructions which is bytecode that is run on the Common Language Runtime (CLR), the virtual machine on the .NET platform.
The JVM and MSIL is not an apples to apples comparison, because one is a virtual machine, and the other is instructions that runs on a virtual machine.
Answer: The JVM and MSIL are actually not a good comparison.  MSIL is the intermediate language that all .NET code compiles down to.  The .NET runtime just-in-time compiles the IL into code that can execute on the machine.
MSIL is comparable to Java bytecode.  The Java Virtual Machine (JVM) executes the bytecode in a similar fashion to MSIL on the .NET runtime.  The JVM compiles the Java bytecode down to code that can execute on the machine.
Answer: You really need to read a full length article to get a good answer. And you probably need to clarify if you want a discussion about Java bytecode vs MSIL or the Sun JVM vs the CLR. This should help.link text

Java and ASP.NET


How to read this symbol, a', in English?

Question: While reading a English Syntax book, I wondered how I have to read a', a'', a''' in English.
Would you tell me how to?
Comment: I think most of us would like to see the context first. They might be pronounced _a prime, a double prime_, and _a triple prime_ respectively, but that might not always be the answer.
Comment: @FumbleFingers McCawley says somewhere (a footnote to Ch. 1?) that ***A′, P′, ... X′*** were originally notated with a bar over the character, ***Ā***, &c, and that when the notation with the prime symbol was adopted for easier typesetting the expressions continued to be read ***A-bar, P-bar***, &c. Hence [X-bar theory](http://en.wikipedia.org/wiki/X-bar_theory).
Comment: @StoneyB: I found it in my copy by looking up *X-bar syntax* in the index, which led me to the discussion in Ch7 footnote 7. McCawley says that in *his* approach "multiple bars make no sense" in respect of A,P,V - but as you say, he does use them when "numbering" his example usages.
Comment: McCawley's *Syntactic Phenomena of English* uses ***A, P, V*** for *Adjective, Verb, Preposition*, and ***A', P', V'*** for *Adjective phrase, Verb phrase, Preposition phrase*. It doesn't use the double- or triple-tick versions though, so I just think of them as *A-tick*, etc.
Comment: @FumbleFingers Yes - because lower-case a, b, c are not in his usage symbols of constituents, and the ticks are not 'bars'.
Answer: I'm guessing that you are referring to McCawley's numbering system for example sentences:
(1) a.
   a′.
   a″.
   a‴.
   b.
... and so forth.
These are not actually English words but typographic symbols. Like the tree diagrams, they're not really intended to be spoken.
If you have to speak them, you may as J.R. suggests say a-prime, a-double-prime, etc. (which is a use borrowed from mathematics), or you may as FumbleFingers suggests say a-tick, etc. (but that is a British rather than US usage).
Comment: I'm British and I've never heard "a-tick". In mathematics, it would be either "prime" or "dash". (No, I don't know why "dash", when a dash is a completely different piece of punctuation.)
Answer: I'm most familiar with it in mathematics, where they are used as related designations of a variable a (or more commonly x, y, or z). I have always read them a-prime, a-double-prime. Haven't really come across a‴ before, but a-triple-prime makes sense.  Wikipedia begins with this entry for Prime (symbol):

The prime symbol ( ′ ), double prime symbol ( ″ ), and triple prime
  symbol ( ‴ ), etc., are used to designate several different units and
  for various other purposes in mathematics, the sciences, linguistics
  and music.


Purchasing semiconductor substrates

Question: I'd like to make a comparison of prices, availability and properties of semiconductor substrate layers like Si, Ge, GaP, AlN etc. I wonder what are the problems related to getting such data, what are the leading companies that sell such things, what's the quality, waiting time and so on. I'm not going to buy one, It's just a little research, that's why I ask here and not the companies directly. Your own experiences (what problems you've encountered and maybe some sample prices or company names?) are much appreciated.
Comment: I'm making this CW since it's basically looking for a list of answers. (For the record, I do think it's very close to being off topic)
Comment: David, I didn't want the question to look like this. The websites or prices are not required for an answer to be good, although I meant they'd be useful. I have rewritten the question, I hope it looks better now. Thanks for the comment!
Answer: As an engineer, I've had to get pricing on stuff I wasn't going to buy many times in the past. I doubt you'll find a website which will have the prices, but you can find them yourself in a few hours work. What you do is this:
Call them up and ask for a "sales rep" (abbreviation for "sales representative" but nobody calls them by the full name) tell him/her that you're working at a physics lab (I presume you are) and that you need "budgetary pricing". This is pricing that includes no discounts. Budgetary pricing is not an offer to sell. So if the price suddenly goes through the roof because of a revolution in some obscure country budgetary pricing won't get them into trouble. They should give this to you without a lot of trouble as it's not secret information. I've always assumed that they don't put it on their websites because (a) it changes, and (b) it might be construed as being an offer to make a contract.
And if you can't get information from their website, ask them to give you a "data sheet". That should be all you need.
Hey, I'll get you started. Here's a company that sells wafers for the valley:
http://www.svmi.com/
Here's their extensive non silicon product line:
http://www.svmi.com/non-siliconwafers.aspx
Here's their contact info:
Tel:  408.844.7100
Fax: 408.844.9470
Email: firstname.lastname@example.com
Now when you talk to them, do not sound like a complete idiot. Make sure you know everything about their product BEFORE you pick up the phone. Make yourself a temporary expert on their product line. Know what size you're interested in and what level of quality, etc. Decide in advance what year you're asking for (new stuff gets cheaper with time), and the approximate quantity.
If possible, use their website to determine the actual product number for the item you're interested in. By giving them a part number you are making their job very easy. Sales people are not, by nature, inclined to annoy potential customers. Make it easier for them to give you a price than it would be for them to tell you to go away. If you give them a part number it will be very easy to look up a number for you. Do not waste their time by asking for them to speculate about exactly how these prices will change in the future. (But if they're bored they might have time to talk to you about this.) They should be able to tell you that they "expect that these prices will drop as production ramps up", or give you a vague idea, and maybe you'll get lucky. But remember that you're asking industry to do you a favor for no real good reason.
Comment: In the early days of the internet, I worked at a company that made graphics cards (Renaissance GRX renamed Zymos then Appian Technology). One day we got an email that had accidentally been sent to "all" by one of the vendors who sold  us integrated circuits. Instead of the list prices for ICs, it gave the actual prices they were charging to all their customers. My buddy in purchasing said that this made his job much easier. :)
Comment: After typing this up, I had this realization how to explain pricing in things like this. Americans get used to paying for stuff at stores where the price is listed on the item with no room for negotiation. An exception is buying cars, where most places you begin with the "list" and then negotiate. When you're asking for budgetary pricing, you're basically asking for the "list" price. This is not secret, it's just not advertised. What each individual company actually pays, that's a secret.
Answer: I was looking for a company who can provide Si (and potentially other) wafers of various types, and I can say the following:
1) You will have a hard time finding 'fixed' pricelist. Companies are not ready to quote you unless you are ready to buy XXX amount. 'I am just checking prices around' not gonna work.
2) Price is drastically different if you are getting standard wafer (which is produced in mass quantity for fabs). If you are getting non-standard wafer you not going to get price/wafer price (or it's going to be ridiculously high). You going to be quoted for crystal growth and slicing+finishing separately. And of course price is negotiable for large quantity.
3) You can get almost any needed purity (=more recrystallization passes). It just costs additional money. (so going from 1kOhm to 10kOhm Si resistance adds 30% to the crystal price before slicing)
4) Delivery of stock wafers depends on your luck & their laziness. Custom crystals take ages to make.

Purchasing semiconductor substrates


BIC for generalized additive models

Question: Is there any way to use BIC in model selection for gam? And if so then how to extract bic?
Answer: As long as the different observations $\{y_i, \mathbf{x}_i\}_{1 \leq i \leq T}$ that you use to fit your GAM are i.i.d. (and assuming that the number of observations $T$ is reasonably large) it is perfectly possible to compute its BIC.
Let's assume that your model has the following form:
$$
g(\mathbf{E}(y)) = \alpha + f_{\theta_1}^{(1)}(x^{(1)}) + f_{\theta_2}^{(2)}(x^{(2)})+ f_{\theta_3}^{(3)}(x^{(3)}) + \dots
$$
where $\mathbf{x} = [x^{(1)},\dots,x^{(N)}]$, and where $\theta_1,\dots,\theta_N$ are the free parameters of the functions you are fitting on your data. Then the total number of free parameters in your GAM will be
$$
1+ \sum_{j=1}^N |\theta_j|
$$
i.e. the number of free parameters in each function, plus one (for $\alpha$).
Comment: Why in the world is this flagged as low-quality post?!

BIC for generalized additive models


Android Custom Compoent extending FrameLayout in Code

Question: I would like to create an Android custom component for a game.  The basic idea is that the custom component would be square in shape and contain other square ImageView components inside it.  The ImageView components inside may be scaled and/or cropped as needed, but must remain square.  The number of rows == columns, always.  The difficulty level determines the exact value of rows and columns at runtime.  As the game gets more difficult, the number of rows and columns will increase equally, but the scaled size of each ImageView will shrink accordingly.  I would like the components to have some fixed small spacing between them, mostly so it looks nice.  The display won't be scrollable, all items must fit on the display at the same time.
After a bunch of failed attempts, I'm getting frustrated and I'm not sure what is the best approach is to make this custom component.
My latest idea would be to do roughly the following:
I create my custom component class by "extends FrameLayout".  In my constructor, I create an arbitrary small square ImageView object in code.  I'd like others to reuse my custom component someday, so I do it in code rather than XML so that the custom component doesn't rely on any external XML drawable having to be defined.  I set the scale type so that the ImageView retains it's "squareness" (I think I want fitStart?).  I set the square ImageView's layout_width and layout_height to "fill_parent", so the ImageView fills in as big a space as is available in the containing FrameLayout.  I add the now large and square ImageView to my layout using addView().
Next I create a RelativeLayout object and also programmatically add it to myself using addView().  Because my base class is a FrameLayout, I think this will make the size of the RelativeLayout the same as the square ImageView previously added.  At least that's how I read the documentation.
Next I measure the ImageView to see how large it is.  I don't think I can measure myself because my previous attempts failed at this.  I kept getting 0 for my size.  My research said this was because I can't measure myself during construction.  This turned into a Catch-22.  When I tried to scale my image to the available space, I couldn't because there was no space available yet.  My hope is that because I changed to using the FrameLayout as my base class and I add the ImageView to it, I will be able to measure my newly created and correctly scaled large square ImageView.
If all goes as planned, I now know how big the space available is on the user's device for my RelativeLayout because it's the same as my ImageView.  By knowing how much space is available and how many rows and columns need to be displayed, I can correctly scale each ImageView I add accordingly, assuming I remember to account for the spacing between the ImageViews I add.  Now I no longer need the square ImageView and can make it go away if I want.
If reasonable, I would like the large ImageView to have rounded corners and each ImageView added also have rounded corners.  With a small gap between ImageViews added, this would look cool for gameplay.  This way I can leave it as a background.
This seems like a good solution, and better than my previous attempts that didn't work, but if there's a better way..., I'm listening.
Here's some psuedo-code that says mostly the same thing as above to the best of my understanding:

construct()
{
    ImageView squareImageView = new ImageView(Square);
    LayoutParams squareImageLayoutParams = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    squareImageLayoutParams.addRule(fitStart);
    addView(squareImageView, squareImageLayoutParams);

    RelativeLayout relativeLayout = new RelativeLayout(context);
    LayoutParams relativeLayoutParams = new LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);
    addView(relativeLayout, relativeLayoutParams);

    int size = squareImageView.getWidth(); // Should be the scaled size and square.
    squareImageView.setVisibility(INVISIBLE); // maybe?

    loop for each row and col
    {
        crop, scale and add each image to the relativeLayout object.
    }
}

My most basic question is if this seems like a reasonable solution?  If so, there's a bunch of things in the psuedocode I don't know how to do (yet).

How do I create a small square ImageView in code?
How do I set the scaleType in code?
Will I be able to measure my square ImageView and get the correct size?
Is there a better way to remove the square ImageView other than making it invisible?
Will making my square ImageView invisible make it unmeasurable?
I see something called a ShapeDrawable, would this be better than an ImageView for making a square?
How do I crop an ImageView to be square, distributing the loss equally to both sides?

I certainly don't expect anyone to know all these answers, but if you know any answers you can share, I would appreciate it.
Thanks.
Comment: I'm still getting a 0, I'll try to see if I can move the size test to a later point in the code.
Answer: There is a lot of built-in functionality for proper scaling to the available screen space. I do not fully understand why you want to measure the ImageViews.
Have you considered using weight? I would try a fixed size GridView (or TableLayout, or a LinearLayout of LinearLayouts). If contents are weight'ed properly, they will retain their "squareness". You could use the attributes verticalSpacing or horizontalSpacing of a GridView, or you could make empty Views for spacing in order to put weight to the spaces as well.
Do not set the weightsum attribute of the parent element, but make sure the sum of your elements' weights horizontally are equal to their sum vertically, and your square ImageViews will always scale properly, regardless of how many elements you got in there.


Can two different points have the same potential?

Question: I have read in my textbook that the flow of current takes place till there is a potential difference between the two points and stops when they acquire the same potential, but how can two different points have the same potential?
According to me potential at a point is the work done in bringing a positive test charge from infinity to that point.
Answer: Two different points in a circuit can have the same electric potential in the same way that two different points on a high shelf have the same gravitational potential.

If you lift a book up to point 1 on the shelf, you must do some work to overcome gravity.
If you instead lifted the book to point 2 on the same shelf, you must do the same amount of work because you lifted against the same gravity over the same distance.

You are "resisted the same amount", so to say, or you could say that it is "equally tough". So, you must apply the same amount of work. Similarly, if the "touchness" to move a charge to one point is the same as to move it to another point, then the work required to do so is the same.
The term potential energy or simply potential (a per-unit measure) is our measure for the "toughness". When it is "tougher" to reach a particular point, we say that the point is at a higher potential.
In a circuit, the "toughness" to move a charge to a point purely depends on the electric repulsion/attraction from that point:

It is very "tough" to place a negative charge on the negative battery terminal, for instance, because the repulsion is very large here (because a lot of negative charge is already accumulated here, and they resist further from arriving). So, we say this point is at a high potential.
If you attach a wire to this negative terminal, the negative charge from the terminal spreads out along the wire. When evenly spread out they will stop moving, because they mutually cancel each others repulsion out. The repulsion is therefore equally large all over this wire (if it at one point was not equal to that at a neighbor point, the charge on the wire would rearrange until it really is equal). Placing a new negative charge anywhere on this wire is therefore equally "tough" at any point. We say that the whole wire is at the same high potential at every point.

So, there is no electrical potential difference - no voltage - between two such points on this same uninterrupted wire. In the same way that there is no gravitational potential difference between two point in the same horizontal shelf. A ball placed on this shelf will not want to move to the other point; there is no tendency for it to do so. And similarly, a charge on the wire will not want to move anywhere else on this wire - no current will want to flow - since there is no tendency for it to move. Only a difference in potential gives them such tendency.
Answer: Consider a vector field $\vec{E}:\mathbb{R}^3\to\mathbb{R}^3$. It is said to be closed if, by definition:
$$\nabla\times\vec{E}=\vec{0}$$
where $\nabla\times\vec{E}$ is the curl of the vector field $\vec{E}$.
This vector field is said to be exact, if there exists a function $\psi:\mathbb{R}^3\to\mathbb{R}$ such that:
$$\vec{E}=\nabla\psi$$
where $\nabla\psi$ is the gradient of the function $\psi$.
Now, in electromagnetism, we know that the electric field generated by a pointlike charge placed at the point $\vec{\xi}$ in the point $\vec{x}$ is of the form:
$$\vec{E}(\vec{x})=k_0\frac{q}{||\vec{x}-\vec{\xi}||^3}(\vec{x}-\vec{\xi})$$
It can be checked that the curl of this field is zero:
$$\nabla\times\vec{E}=\vec{0}$$
In general, this condition is not sufficient to conclude that there exists a potential $\psi$, since not every closed field is extact. The converse is obviously true, since $\nabla\times(\nabla\psi)=0$ for every $\psi$. In order to conclude that the field is exact, we must be in a simply connected space. In most of every physical situation, our theory is defined in a simply connected space and then we can assert that our electric field is exact, and we can define a potential.
This is the true definition of a potential. Moreover, by calculating it in different situations, it can be seen that there can be equipotential surfaces, or lines, in which every point is at the same potential.
Comment: Woah Kevin, I am merely in 10th standard, I didn't understand a word you said
Comment: I don't see how anything before the last paragraph is needed.
Comment: Because it leads to the correct definition of the potential..
Comment: @divyamsureka sorry, didn't know that!


Why is tl;dr at the end?

Question: Why is it in the end, I see this often after reading the material. The definition is too long, didn't read, but by the time I see the tl;dr, I've already read it. It breaks the flow of the whole story and becomes redundant if the entire article is read. I have no idea why so many writers continue to put it in the end. Its oxymoronic. What is a good reason to put in the end?
Comment: Closely related, possibly duplicate: https://writing.stackexchange.com/q/32819/23927
Answer: It's targetted at people who won't read the thing. Given that you read the thing, you aren't its target audience, so all it needs to do for you is stay out of the way, which putting it at the end does (whereas putting it at the start might lead to you not reading the thing when you otherwise would do, which is a negative for the author).
The target is people who skip past the text without reading, who see a quick summary at the end that they are willing to read.
Answer: Basically, tl;dr/TLDR stands for Too Long; Didn't Read/Too Long Didn't Read (you can use or take away the semicolon). Sometimes tl;dr can stand for Too Lazy; Didn't Read, but is mostly the first example.
The most common use for this common phrase as an author is explained in a Howtogeek.com article:

Along this same line, writers sometimes include a TLDR at the top or bottom of their web article, email, or text message. This is meant to be a summary of what the author is saying, and it's a disclaimer that the details of a long text may not be worth every reader's time. A ten paragraph product review for a crappy laptop, for example, could simply start with "TLDR: this laptop sucks." That's the quick summary, and you can read further for details.

So where should you put tl;dr in your article? Well, it depends; there are pros and cons to using this phrase at either the beginning of the text or at the bottom. Howtogeek.com also describes this:

When using TLDR as an author, your job is a little more complicated. Placing a TLDR-summary at the beginning of an article or email can save the reader's time or serve as a quick introduction, but it can also give the reader a reason to skip the details of your text.

A TLDR-summary at the end of a long text is sometimes more desirable, as it allows you to sum up all of the details that the reader is digesting. But in some situations, this use can feel a bit sarcastic. It's as if the author is acknowledging that their own wall of text can adequately be understood in a single sentence.

So really it depends on what your writing, what your style is, and how you want to sound.

Why is tl;dr at the end?


Using functions to manage relationships in Backbone

Question: I am working (for the first time) with Backbone.js in creating a reasonably simple application. I am currently working with two entities that have a one-to-many relationship:

Project: has many groups
Group: belongs to one project

I looked at a few different ways of representing relationships between models, from Backbone's own recommendations to Ligament to Backbone-relational. However, I eventually settled on using simple function calls. For example, within my 'Project' model, there's a function called groups():
groups: function() {
  return new Collections.Groups(groups.where({project_id: this.get('id')}));
}

And within the Group model:

project: function() {
  return projects.where({id: this.get('project_id')})[0];
}

This allows me to do things like:

var foo = new Project();
var foo_groups = foo.groups();
foo_groups.at(0).get('name');

var bar = new Group();
var bar_project = bar.project();
bar_project.get('name');

To me, the tradeoff here is the overhead of maintaining up-to-date relationships (when using something like backbone-relational) versus the processing time used calling the 'groups()' function each time you want to get a project's groups.
Can anyone advise me on any pitfalls I may encounter down the road as I build out more relationships in this way, perhaps recommending a better solution (other than the extensions mentioned above)? The application will eventually have about 6 entities with a variety of one-to-many and many-to-many relationships
Comment: i guess we're on same boat; spent hours to find righteous and easiest way to deal with hierarchies between the models. I hope somebody answers here..
Comment: have you found your time-proven favourite solution?
Comment: I'm currently using a method written about here: http://slashhashbang.com/2011/10/lightweight-relation-modeling-with-backbone/. It overrides 'set' and makes it very easy to handle simple top-down relationships
Answer: Project.groups
I have an implementation of what I call AutoUpdatedCollection.
I use it in the scenario you have a shared Collection which contains every Model of one class, and this Collection is used to populate sub-Collections those have to be updated when the shared Collection is updated.
Check the implementation of the Backbone AutoUpdatedCollection.
Following your example I suppose there is a common/shared Collection called window.groups, then I'll implement Project Model like this:
// code simplified and no tested
var Project = Backbone.Model.extend({
  initialize: function(){
    this.groups =
      new App.AutoUpdatedCollection({
        name:             "Project-" + this.id + "-groups",
        sourceCollection: window.groups,
        filterField:      "project_id",
        filterValue:      this.id
      }).filteredCollection;

    this.groups.on( "add", this.addGroup, this );
    this.groups.on( "remove", this.removeGroup, this );
  }
});

Maybe is not as simple as this, if you have any problem let me know.
Group.project
I'd just initialize the Group.project attribute in the Group.initialize():
var Group = Backbone.Model.extend({
  this.project = window.projects.where({id: this.get('project_id')})[0];
});


Is "reverse success" a readily understood phrase to English readers?

Question: I'm translating a Russian text about a writer who only got famous in his home country AFTER hitting the big time abroad. The author of the text calls his success at home a kind of "reverse success" in two separate phrases with two different Russian words that translate roughly as "reverse" (obratny and vozvratny). These two words are all about things being reversed, back to front or reflected. Is "reverse success" fine here, or might you put a different English adjective there, or else abandon literal translation altogether and go for some more roundabout phrase? One of the instances is a headline, so it would have to be something fairly concise.
Comment: "fame, first abroad, [and only] then at home" (I'm just making this up.)
Comment: I suspect the Russian words mean 'reflected' rather than 'reversed'. The Russian authors success abroad was reflected or mirrored in his home country, is how I suspect the concept is being expressed.
Comment: Actually, the Russian words are based on roots that have the sense of "turn" or "spin". Obratny is used of a "return ticket", for example. Reflection is something that happens simultaneously with light, so I was leading you a bit down the wrong track, there, but this "turned around success" is a bit more like the action of a boomerang, if that's a better analogy!
Answer: No, reverse success wouldn't work. The most likely interpretation of that phrase would be, more or less, failure.
An example from google books:

a reverse success mapping (failure mode map) technique was applied...

Here is another (source):

In the context here, however, these phenomena are indicators of the failure of technological transfer to Third World countries — even in this case, in a country which has officially adopted a pro-science- technology stance. Of course, in reverse, the policy is a success. The emigrant engineer (and doctor and scientist) keeps our own technological culture thriving. The growing number of co-authors with Indian surnames in science literature is indicative of this reverse success.

Word suggestions
I don't know that there is an established word that you could use instead The following are kind of metaphorical and improvized, but I wonder what you and others might think of them:
retroceded success: to retrocede means 'to cede (territory) back again to a country'. If coutries can be conceptualized as 'giving' and 'taking away'success to someone, this suggest that the home country first withheld success, and now is giving it back.
retroflected success: this has association with retroflex ('bend over backwards') and retroreflection ('The reflection of light in such a way that it travels along the path it took prior to reflection, but in the reverse direction'). It (perhaps) suggests the success streaming in the direction back towards the home country.
Comment: "reverse order" may be what you need, where the person is recognized first abroad and then at home, where success is "reflected back"
Comment: @ben-mcgah Well, the context, as always, is everything. Good luck!
Comment: Interesting examples, which appear to rule out the literal translation, cheers for that! I still think I MIGHT get away with it, given adequate context in the article, and by generous use of speech marks around the phrase. Those two proposals are too technical for this context, unfortunately. All kinds of words like "second-hand", "indirect" or "secondary" are echoing around in my head, but none quite fit! There comes a point when you have to throw your hands up in surrender if you're being paid to translate a long text, though.
Comment: @xanne Oh, that's a great suggestion!
Comment: You've got the noggin a'joggin there, @Xanne, cheers! I'm thinking about some way of saying "backwards success" now...


Are there any sources for types of learning to memorize?

Question: I am interesting in working on memorizing something - anything that I can have with me in my head that I can review at random times throughout the day. In terms of the "what" to memorize, I am curious if there are any sources that describe whether there is something in particular this is good to memorize (I.e., Mishnayos, certain parts of Gemara?)
Comment: Related: https://judaism.stackexchange.com/questions/77963/memory-techniques-for-torah
Comment: Throughout Shas there are many maamarei chazal which praise people for memorising their learning as well as listing techniques for memory retention, but not actually saying what one should learn.
Comment: The Rebbe Rayatz extols the benefits of learning mishnayos by heart in yesterday's [Hayom Yom](https://www.chabad.org/dailystudy/hayomyom.asp?tdate=5/29/2023).
Answer: First of all, it is important to remember that you'll need to not take a huge load upon yourself with regard to memorizing texts, as Rashi writes:

and studying much is a weariness of the flesh And if he comes to memorize large amounts, more than the heart can grasp, that is weariness to man, but let one not say, "Since I cannot complete the work, why should I begin?"

Rashi's advice is:

What you can, do, and let your heart be to Heaven.

In the sefer "Orchos Chaim: Ben Torah For Life", Rabbi Aaron Lopiansky describes different goals of learning Torah (p. 153, Chapter 5 What to Learn):

To know that which is incumbent upon us to do;'
To be inspired;
To become intellectually engaged in Torah.

These three form the foundation of my answer to your question:

I am curious if there are any sources that describe whether there is
something in particular this is good to memorize (I.e., Mishnayos,
certain parts of Gemara?)

Certainly Halacha (Maybe start with learning Mishnayos by heart), since Rabbi Lopiansky writes: "The first reason is that without learning halachah, we will not perform the mitzvos properly [...]. Only by learning Halacha can we recognise an issue when we see it" (Ibid., p. 153).
Rabbi Soloveitchik in his commentary on the Gemara, "Reshimos Shiurim" explains that the mitzvah of learning the Written Torah,

obligates each person to memorize and recite the verses orally [in
order to fulfill the mitzvah of learning the Written Torah.]

So, according to Rav Soloveitchik, memorizing pesukim in Torah is always a good idea to start off with.
Based on Orchos Chaim by Rabbi Lopiansky, I would recommend memorizing the following sources (choose for yourself what is manageable and what not).
Halacha

Basic Halachos without Mishnah Berurah (review it a few times, this will help memorizing it). For example: learn the halacha of Krias Shema or learn halacha of Shabbos;
Mishnah Berurah (I would recommend learning the same halachos as you did in step 1);
Shulchan Aruch and then learn the Rama;
Chayei Adam.

Please note that I am not saying you should memorize the whole of Shulchan Aruch. Rather, choose a topic that suits you. As one of my most favourite lessons in Gemara teaches us:

Rabbi said: One can learn Torah only in a place which his heart
desires

Gemara

Choose a perek in Gemara and learn it thoroughly with the commentary of Rashi;
If you are fluent in Rashi and that Gemara, you can choose to memorize that particular Tosfos on that Gemara you've learned.

One of the best advices Rabbi Lopiansky gives, is:

Choose material to learn that can be clearly defined. This might be a perek in Shas, an area of Halachah, etc.

In addition to this, I would like to end this answer with some great piece of advice from the Ramak (Moshe Kordovero), in his work "Or Neerav":

The reader should approach these books in two ways. First of all, he should review the texts many times, making notes in order to remember [his] studies fluently. He should not delve too deeply at first. Secondly, he should study the material with great concentration according to his ability.

The Steipler Gaon responds in a letter send to him (Karyana D'Igarta; letter titled כל ת"ח מוכרח ללמוד כל חלקי התורה ) that the main goal of the mitzvah of learning Torah, is to delve deeply into a subject, so that at the end of your study, you'll be able to give instructions in that matter. Let's say you are learning Berachos, then you'll be able to respond to matters regarding berachos at the end of your studies. That is how one should approach his studies.


How can I make an external drive behave as an internal drive?

Question: My question is pretty much summed up by the title, I have an external drive which I'd like to have recognized as an internal drive. How can I do that? Thanks for looking at my question. By the way I am running 10.11.3 on mbp
Answer: I just found this answer, sorry I tried looking first but couldn't find it....
You should be able to do this with dd by setting Removable to False.
Unmount your disk, then run…
dd if=/dev/zero of=/dev/disk2 bs=1 count=1
Don't forget to replace disk2 with the actual disk identifier.
This command will erase the contents of the disk. Untested, be careful, usual 'not responsible if stuff goes wrong' applies :)
Comment: @Gene: Doesn't bs=1 mean 1 byte? And with count=1, wouldn't that mean to just write a value of zero to the first byte of the disk?
Comment: This answer is probably wrong. Byte 0 (the first byte of the first block is apparently always zero). Additionally this will probably **not** erase your disk!
Comment: Well first I guess I should say that the drive was empty, but what do you mean by an install, install what?
Comment: Not sure if this helps, but I tried it and even though I couldn't tell if the drive was erased since it was empty. Disk Utility does label it as an Internal Physical Volume...


How would I best make this SEO_able?

Question: I have a search engine that searches albums.
For each music album, I have a page.
So, the work flow goes like this:

People search for music titles
The search engine displays a list of albums.
People click on an album to go to a details page.

I want google to index my front page and the details page. I want the details page to be highly ranked. How can I build a sitemap for this?
By the way, I have about 5 million albums (but I want the top 1000 ones to be highly ranked on google)
Answer: You would not use a sitemap for that many results.  You would want each album to appear as a page with a unique URI to reference that page.  That way the search engine can crawl your site by crawling links since search bots cannot submit form data.  Each of those URIs should be simple, meaning limited to this part of the URI syntax:
scheme://authority_segment/path
Program your web application to remove and throw away any extraneous data, such as query string or parameters.  If you do this you have to be sure that you are watching for URI poisoning or SQL injection even through means of character encoding.
Answer:
How can I build a sitemap for this?

By pulling the addresses out of your database and creating a XML file with a high priority for some selected pages. Somehow I think that isn't your real question …
Answer: If I wanted to automate building a site map for a site like this, I'd employ Python. I'd pretty much write everything from the ground up (except the data store access). The format is quite simple.
I'm not sure I quite understand your question...

How would I best make this SEO_able?


Smile Strangle and Market Strangle

Question: What is the difference between Smile Strangle margin and Market Strangle Margin in fx derivative market? Is it just variation in convention or is there any mathematical relationship between the two?
Answer: Do you mean actual margins for listed products or clearing on say CME? I am not familiar enough with this but a quick research shows that the CME seems to simply use 3 calls with a +1:-2:+1 configuration. Strikes need to be equidistant in this definition;
strike2 – strike1 = strike3 – strike2

Maybe I am wrong but I am assuming you simply mean smile butterflies and broker flys (also called market strangles). Generally, it's mainly a means of quoting FX vol.
ATM Delta neutral Straddles (DNS), Risk Reversals (RR) and Butterfly (BF) quotes completely describe the entire surface. ATM the level, RR the skew and BF the kurtosis. There are some complications like premium included / excluded Delta, Delta style (spot vs forward), spread models used etc.
One such complication involves how the BF is quoted. To get actual vols for calls and puts, one needs to transform these and solve for call / put vol.
Smile BF is simple:
RR = Vol of an OTM Call Option (C) - Vol of an OTM Put Option (P)
BF = ( C + P ) / 2 - Vol of ATM DNS

it's simple to show that
C = ATM + BF + RR/2
P = ATM + BF - RR/2

where you get say a 25 Delta call if you use 25D RR and BF respectively.
The above uses smile BF but brokers frequently quote market BF (short broker fly). These are a bit more involved but FX Volatility smile construction by Dimitri Reiswich and Uwe Wystup explains this in more detail (if this link does not work anymore, it can be searched easily).

Smile Strangle and Market Strangle


Travel to Takasaki from Tokyo

Question: Can anyone tell me if I can avail any pass for return travel between Tokyo and Takasaki on the same day? I'm looking for the cheapest travel option. I've a Suica card. Thanks.
Comment: Are you saying you want a buy a pass just for this purpose? Or are you looking purely at the cost (fare)? Are you getting a JR Pass for your trip regardless of this?
Comment: I'm looking for a pass purely for this purpose. Thanks.
Comment: The cheapest option for a single trip between two reasonably large cities is almost always the bus. Here, Tokyo to Takasaki return by bus is 1550 yen, versus 1940 for the cheapest train.
Comment: You're much better off buying a ticket (or using your Suica card).
Comment: Thanks. So, the the one way fare using the Takasaki Line train is 1940 yen. Apparently, for the return travel one needs to pay the same which means there is no discount for the return journey which is odd.
Comment: No, it is not odd; there is no automatic discount for return trips in Japan. You can get a discount in some cases, but not all.
Answer: Note that I am assuming you are leaving from Tokyo Station and heading to Takasaki station, since you didn't specify any stations.
@fkraiem has pointed out the cheapest choice is highway bus. My apologies.
Taking the Nippon Chuo bus will be 1550 JPY. You have a few stops you can board from, but note that you probably have to buy the ticket ahead of time (there are bus companies you can buy the ticket on the spot, but I don't know about this particular one). Tickets are for only valid for the time you purchases, so make sure you are on time. You can purchase online, through phone, through convenience store kiosks or through licensed sellers. However, this company doesn't seem to have English support, so it may be a task. Information page of that line is here (in Japanese). It will take you about 2 hours, but note that the times fluctuate depending on the traffic and weather conditions.
If you are looking for the simplest solution, it would be just taking the straight route, the JR Takasaki Line (to Takasaki). This will cost you 1944 JPY. If you bought a ticket instead of using SUICA, it's actually 4 JPY cheaper!
Note that this will be a little over 2 hours. Depending on your departure time, there may be a few options with a transfer to get you there faster (by 5-10 minutes).
If you have a JR Pass, you could take the Shinkansen straight there in half the time. The cost otherwise would be at least 4410 JPY. The round trip would be 8820 JPY, so a JR Pass just for this purpose would not be worth it.
There is a Gunma regional free pass (Gunma One Day World Treasure Pass), which you can use to travel freely around Gunma by JR lines. But it costs 2200 JPY, and the closest you get to Tokyo is Fukaya. If will be 1320 JPY to Fukaya from Tokyo, so in total that would be cost you 4840 JPY for the entire trip. Also, the pass is only sold in spring and summer.
In the future, I suggest using a train schedule site to help you plan out, like Navitime or HyperDia.
Comment: Might be wise to include both. Some people (like me) are "allergic" to buses and would almost certainly be willing to pay 400 JPY extra to take the train.
Comment: Wrong, bus is cheaper.
Comment: @fkraiem Ah, I didn't think of bus at this distance. Care to write your own answer, or should I append?

Travel to Takasaki from Tokyo