I am currently writing a small class in C# which will take an image, decompile it down to a byte array, obfuscate the data into a proprietary format (thus making it unreadable), and store said data into a file. The class will also optionally recompile the data, thus decrypting the proprietary format back into an image so that it can be used.  I was just wondering if someone with a better vocabulary than myself could throw a couple of words at me that would mean the same thing as encrypt and decrypt, but as a single word. I understand that there may not be a word for this, because the words hold very different meanings at their base level. However, if someone has anything good I would love to hear it.
I am looking for a word that describes both of these activities, however the word coding does not seem to be suitable.   Likewise with encryption and decryption, cryption does not work well.
I am currently undergoing a full Apostol Calculus I reading, and with few chapters left I've began planning what other books to read. I was thinking about finishing both Apostol Calculus l and ll, and then read Apostol mathematical analysis. I'm not pretty sure whether these are the best books or if they will provide me with a strong math basis. I've already taken calculus i, ii, iii and linear algebra. The reason I've chosen Aapostol volume 1 and 2 is that I've heard they cover almost all the topics I've seen and will see in the next semester/s. I would appreciate if somebody could give me some advice about this. I really like to have a book that really gives me hard and challenging problems. I don't know whether to read Spivak Calculus book or not. We know Euler formula:  $$ e^{ix}=\cos(x)+i\sin(x). $$  Does this formula work if we replace real number $x$ with complex number $z$? The number of (non-equal) forests on the vertex set V = {1, 2, ...,n} that contains exactly 2 connected components is given by The number of (non-equal) forests on the vertex set V = {1, 2, ...,n} that contains exactly 2 connected components is given by $\sum_{k=1}^{n-1} {n-1 \choose k-1} k^{k-2} (n-k)^{n-k-2}$.  I am unsure how to approach this question. Could someone guide me through the proof? If G is a spanning tree and it is disconnected then I know it is a spanning forest. Also, I know by Cayley's thm that there are $n^{n-2}$ nonequal tree on a vertex set V = {1, 2, ...,n} which is where i'm assuming the $k^{k-2}$ comes from but I do not understand where the rest of it is coming from. opengl storing multiple indices into indices buffer Canned reasons for up/down vote (w/ example of how it would work) I'm annoyed by down voters that don't explain why they down voted a question or an answer. Although, at the same time, I understand that they . I think there is a middle ground, though, where the voter can remain anonymous, while the poster can get aggregated feedback on ways to improve the post.  Rather than having to imagine what it might be like, the current stackoverflow engine can emulate this rather effectively with the use of comments and the up-voting of those comments (essentially saying "I agree"). So I thought I would give it a try. The only difference is that in this testing post, you will always see the list of "canned responses" where as in the complete version, it will most likely be hidden in a popup (e.g. when you hover over the score of an answer/question). To try it out, simply up or down vote this question (or one of its answers), and press the up arrow next to the comment which best describes why are voting that way. For example, if you hate this idea, give this a down vote, and then press the up arrow near -1: I don't like this idea.  In addition to retaining anonymity, this will also save time for the voter so that they don't need to write out the comment. This wouldn't be required, obviously, and there could be a default option selected don't leave a reason. In addition, there could be a custom option which allows you type exactly why you are down-voting this way. Depending on the final implementation, this could either simply be converted to a comment automatically prefixed with -1:  or +1:; or, to retain anonymity, it would be added to this same list that shows the canned responses and how many users have voted that way.  Here are some ideas for the canned responses:  Question:   +1: Well formatted and thought out question. -1: It doesn't seem like enough time was spent trying to solve this issue on your own. -1: I don't like this idea. (Could be especially useful on meta.stackoverflow.com feature-request.) -1: No prior research/work. (Idea from .) -1: Poor question. Please see . -1: Doesn't contain code. (This would be useful on stackoverflow.com. Idea from )   Answer:   +1: Concise. +1: Insightful. +1: Worked for me. -1: It's wrong. -1: Confusing. -1: Encouraging bad behavior (e.g. answering a question that shouldn't have been asked; see ).   I made this a community-wiki since there will probably be testing of up/down votes. Several of these canned responses have been taken from . This same idea was also . Convert HTML entities to Unicode and vice versa How do you find time period as a function of time for a simple pendulum that is in the form of a hollow sphere that is filled with mercury and there is a hole in the bottom through which the mercury is constantly falling at a fixed rate? I tried creating a function for the time period to check how it varies with the mass of mercury, but I had too many variables.   EDIT: This question was a concept based multiple choice question in my homework book. The option were time period becomes erratic, time period increases, time period decreases, time period first increases then decreases. Elsarticle - Abstract two columns wide I am currently trying to create an article in elsarticle style, twocolumn. The title and text end up in two columns, the abstract however is made two columns wide. Any ideas what I am doing wrong? Obviously I want my abstract to also be only in the first column.  \documentclass[a4paper,10pt,twocolumn,preprint]{elsarticle}  \usepackage{lipsum}  \journal{TexExchange}   \begin{document}     \begin{frontmatter}       \title{Two-column abstract}       \begin{abstract}         \lipsum[1]      \end{abstract}       \begin{keyword}        abstract      \end{keyword}    \end{frontmatter}   \section{Outline}    \lipsum[2-3]  \end{document} Biblatex handling of Dutch "van" prefix This question has been posed in many different variants, but not exactly as I ask here, so please do not consider this as a duplicate.  I use biblatex with the option useprefix. I would like to have the following automatic behavior:   Name prefixes are rendered before the last name in the bibliography, but always in lower case. The name prefixes are ignored for the sake of sorting of the bibliography. In running text, the name prefix is rendered with a capital letter at the beginning of a sentence, and lower case elsewhere (possible using \Textcite vs. \textcite).   To achieve this, I can have three author fields for each concerned entry, with the following scheme:  author = { {v}an Dijk, A.} shortauthor = { van Dijk, A.} sortname = {Dijk, A. van}   Is there a simple way to automate this? Ideally, such a way could also allow for easy changing of the system. The trigonometric ratios of an angle greater than $90^\circ$ are equal to the supplementary angle's ratios.  I'm just clarifying this, but the ratios don't actually exist for angles greater than $90^\circ$ right? (since by definition these ratios are of a right angle triangle). Is it just mathematical custom to assume the ratios of an angle greater than $90^\circ$ to be equivalent to its supplementary angle's ratios? For convenience? Are employments in universities affiliated (or named) with a specific religion restricted to people with the same religion? I just saw an ad in mathjobs.org about an opening in a Catholic university, see . I am not christian. So I was wondering to be eligible for employment in a university or college affiliated with a specific religion, should the applicant  have the same religion, or other people from other religions (or even non-religious people) are eligible to apply as well? I'm looking for a library in Python which will provide at and cron like functionality.  I'd quite like have a pure Python solution, rather than relying on tools installed on the box; this way I run on machines with no cron.  For those unfamiliar with cron: you can schedule tasks based upon an expression like:    0 2 * * 7 /usr/bin/run-backup # run the backups at 0200 on Every Sunday  0 9-17/2 * * 1-5 /usr/bin/purge-temps # run the purge temps command, every 2 hours between 9am and 5pm on Mondays to Fridays.   The cron time expression syntax is less important, but I would like to have something with this sort of flexibility.   If there isn't something that does this for me out-the-box, any suggestions for the building blocks to make something like this would be gratefully received.  Edit I'm not interested in launching processes, just "jobs" also written in Python - python functions. By necessity I think this would be a different thread, but not in a different process.  To this end, I'm looking for the expressivity of the cron time expression, but in Python.   Cron has been around for years, but I'm trying to be as portable as possible. I cannot rely on its presence. I have a dataset for which I have multiple sets of binary labels. For each set of labels, I train a classifier, evaluating it by cross-validation. I want to reduce dimensionality using principal component analysis (PCA). My question is:  Is it possible to do the PCA once for the whole dataset and then use the new dataset of lower dimensionality for cross-validation as described above? Or do I need to do a separate PCA for every training set (which would mean doing a separate PCA for every classifier and for every cross-validation fold)?  On one hand, the PCA does not make any use of the labels. On the other hand, it does use the test data to do the transformation, so I am afraid it could bias the results.  I should mention that in addition to saving me some work, doing the PCA once on the whole dataset would allow me to visualize the dataset for all label sets at once. If I have a different PCA for each label set, I would need to visualize each label set separately. Is this statement true?     You can not travel back in time. If I travel fast enough the clock will start to go backwards, but that does not mean I am traveling back in time. It would only mean that the time reference is producing a negative count. How can I speed up D&D 3.5e combat? iOS StackExchange app doesn't handle non-ASCII correctly The iOS StackExchange app doesn't handle non-ASCII characters correctly, see city name in the screenshot below. What does it mean when multimeter accuracy is marked as: ±0,03%+10Digit? I have a digital multimeter and its accuracy for VDC is marked like this:      ±0,03%+10Digit   This multimeter has maximum display of 80000. So in the 80 V range it can show for example 79.999V.  0.03% of 80V is 0.024V - that is clear for me. But what does the +10Digit mean?  The device in question in . Do all droids have a four alphanumeric character name and does this have any significance? To EAV or not to EAV? I'm trying to solve the following equation:  $$x^3-y^3=xy+61$$  I got:  $$(x-y)(x^2+xy+y^2)=xy+61$$  But I can't go any further. I am looking for a solution in integers.  I need some hints to proceed, please!