I've been using Illustrator to make a UI and as I learn how to use this software, the points of the shapes I made keep getting to fractions of a pixel. I have a great many points now and I'd rather not stop working every now and then to make sure every pixel is aligned to a whole value.  Is there a way to force Illustrator to only place points on whole values? Is there a way to clean up existing points to round them to a whole value?
I have a small Problem that occurs from time to time.   Sometimes, when I copy things or when I put an object from the symbol library on my page, the whole file gets messed up. The screenshot shows it. I make the graphic on the right, Illustrator the ones on the left.   I have pixel snapping checked. Is there a way to tell Illustrator to align everything to pixels no matter what?
Intuition for groups This is quite a non-standard question, certainly for mathematics, though I believe it is no less important (for me and my peers, i.e. grads).  The course I am reading so far introduced us to Groups, rings, fields, etc. in the first year, progressing to characters, reps etc in the latter years.  However, even with representation theory I still don't feel like I have a good intuition.  How do you gain intuition in such an area. I know there will be a response of doing examples, but this doesn't really help - I've done lots already.  Am I doomed. How to monitor USB power consumption? I'm looking for a way to monitor the power being drawn from the USB ports on my Mac.  System Profiler doesn't appear to display this and I haven't been able to find any applications or tools to do the job either.  Can anyone suggest anything (preferably software based)? Currently, the only way to link to a revision (clicking "link"), you just get  which shows what the post looked like at that revision:        Personally, I rarely use this and haven't ever found myself in a scenario (as far as I remember) where I would prefer the way it currently works to what I'm suggesting here.  Could we:   Add another link, or Change the current link   Such that it:   Displays the diff on a separate page (I'd prefer this, since the highlight and scroll thing doesn't always work properly - although perhaps it has something to do with loading images, so it might not apply here, or, if it doesn't, we could fix that instead), or          Highlights and scrolls to a diff, like what is done when you link to an answer () How can I confirm that my I-94 form was correctly processed after leaving the US in 2007? How to find $\partial\chi^2/\partial a$ where $\chi^2=\sum_{i=1}^N\dfrac{D(x_i)-a-b(x_i)^2}{\sigma_i^2}$?  My attempt: \begin{align} \dfrac{\partial}{\partial a}\sum_{i=1}^N\dfrac{D(x_i)-a-b(x_i)^2}{\sigma_i^2} &amp;= \dfrac{\partial}{\partial a}\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\sum_{i=1}^N\dfrac{-a}{\sigma_i^2}\\ &amp;=\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\dfrac{\partial}{\partial a}\sum_{i=1}^N\dfrac{-a}{\sigma_i^2}\\ &amp;=\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\dfrac{1}{\sigma_i^2}\cdot\dfrac{\partial}{\partial a}\sum_{i=1}^N-a\\ &amp;=\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\dfrac{1}{\sigma_i^2}\cdot\dfrac{\partial}{\partial a}a^N\\ &amp;=\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\dfrac{1}{\sigma_i^2}\cdot N\cdot a^{N-1}\\ \end{align}  Is this correct?  EDIT: As per the accepted answer, this is how I got my final partial derivative. \begin{align}             \dfrac{\partial}{\partial a}\sum_{i=1}^N\dfrac{D(x_i)-a-b(x_i)^2}{\sigma_i^2} &amp;= \dfrac{\partial}{\partial a}\Bigg[\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}-\sum_{i=1}^N\dfrac{-a}{\sigma_i^2}\Bigg]\\             &amp;=\dfrac{\partial}{\partial a}\Bigg[\sum_{i=1}^N\dfrac{D(x_i)-b(x_i)^2}{\sigma_i^2}\Bigg]-\dfrac{\partial}{\partial a}\Bigg[\sum_{i=1}^N\dfrac{-a}{\sigma_i^2}\Bigg]\\             &amp;= 0-\dfrac{\partial}{\partial a}\Bigg[\dfrac{-a}{\sigma_1^2}+\dfrac{-a}{\sigma_2^2}+\cdots+\dfrac{-a}{\sigma_N^2}\Bigg]\\             &amp;= -\Bigg[\dfrac{\partial}{\partial a}\Bigg[\dfrac{-a}{\sigma_1^2}\Bigg]+\dfrac{\partial}{\partial a}\Bigg[\dfrac{-a}{\sigma_2^2}\Bigg]+\cdots+\dfrac{\partial}{\partial a}\Bigg[\dfrac{-a}{\sigma_N^2}\Bigg]\Bigg]\\             &amp;= -\Bigg[\dfrac{-1}{\sigma_1^2}\cdot\dfrac{\partial}{\partial a}[a]+\dfrac{-1}{\sigma_1^2}\cdot\dfrac{\partial}{\partial a}[a]+\cdots+\dfrac{-1}{\sigma_N^2}\cdot\dfrac{\partial}{\partial a}[a]\Bigg]\\             &amp;= -\Bigg[\dfrac{-1}{\sigma_1^2}+\dfrac{-1}{\sigma_2^2}+\cdots+\dfrac{-1}{\sigma_N^2}\Bigg]\\             &amp;= \sum_{i=1}^{N}\dfrac{1}{\sigma_i^2}\\         \end{align} Are the LIGO observations proof of a black hole merger, and what happened to the black holes? Recent reports claim that the gravitational waves detected by LIGO match up with the signal expected from two black holes merging as predicted by general relativity.  Additionally, the masses of both black holes were estimated. Questions:  How certain are we that the detected of gravitational waves are necessarily from two black holes merging?  Since supermassive black holes are typically at the center of a host galaxy, what happened to the galaxies that contained the two merging black holes?  For example, did their host galaxies merge?    Edit After reading the answers, I understand that the signals detected by LIGO are proof of the validity of gravitational wave generational artifacts as predicted by general relativity.  When additionally gravitational waves, caused by the merger of the supermassive black holes (those which ARE indeed located in the centers of the merging galaxies) will be detected, since mergers of galaxies could be observed by the methods independent of gravitational waves such as registering the fact of the quasar appearance (). Additional questions:  Could someone offer me the historical ASTRONOMY precedent when the second degree of inference (from the mathematical model, being associated with the theory of Physics) was accepted as the discovery of the astronomical object?  Could someone give a reference to trustable scientific publication, with the subject of study being discussion of requirements satisfying claim of astronomical discovery of an astronomical object?  Have independent scientific sources (outside of members of the LIGO team) analyzed methodology and results of the LIGO signal detection, and published their conclusions with regards of what was actually discovered? Connecting desktop computer to the internet through laptop wifi Due to some home network complications I have had to move my router to a seperate part of the house, therefore the wired network I had set up can no longer work. Before I find the time to go out and buy a Wifi adapter for my desktop PC, I have a laptop that uses a built in Wifi card to connect to my router and this can connect to the internet, and I was wondering if I could somehow access the internet on my desktop PC via my laptop.  I'm hoping for a not-so-complex solution as this will only be set up for a few days, but it is quite vital that my desktop computer gets internet access.  Does anyone have experience in this sort of thing and can help me out? Thanks. How do I test if all minecraft players on a server are in a radius? This has got me. I need a command that tells me if all players on a server are in a radius of a command block. If one of them isn't in the radius, the command will be false. Any ideas? Thanks! ls: cannot access .gvfs: Permission denied Short version: In what circumstances is dd safe to use for copying data, safe meaning that there is no risk of corruption due to a partial read or write?  Long version — preamble: dd is often used to copy data, especially from or to a device (). It's sometimes attributed mystical properties of being able to access devices at a lower level than other tools (when in fact it's the device file that's doing the magic) — yet dd if=/dev/sda is the same thing as cat /dev/sda. dd is sometimes thought to be faster, but . Nonetheless, .  Problem: dd if=foo of=bar is not, in fact, the same as cat &lt;foo &gt;bar. On most unices¹, dd makes a single call to . (I find  fuzzy on what constitutes “reading an input block” in dd.) If read() returns a partial result (which, according to POSIX and other reference documents, it's allowed to unless the implementation documentation says otherwise), a partial block is copied. Exactly the same issue exists for write().  Observations: In practice, I've found that dd can cope with block devices and regular files, but that may just be that I haven't exercised it much. When it comes to pipes, it's not difficult to put dd at fault; for example try :  yes | dd of=out bs=1024k count=10   and check the size of the out file (it's likely to be well under 10MB).  Question: In what circumstances is dd safe to use for copying data? In other words, what conditions on the block sizes, on the implementation, on the file types, etc, can ensure that dd will copy all the data?  ( has a fullblock flag to tell it to call read() or write() in a loop so as to transfer a full block. So dd iflag=fullblock is always safe. My question is about the case when these flags (which don't exist on other implementations) are not used.)  ¹  I've checked on OpenBSD, GNU coreutils and BusyBox. Does $A$ a UFD imply that  $A[T]$ is also a UFD? I'm trying to prove that $A$ a UFD implies that $A[T]$ is a UFD.   The only thing I am sure I could try to use is Gauss's lemma.  Also, how can we deduce that the polynomial rings $\mathbb{Z}[x_1,\ldots,x_n]$ and $k[x_1,\ldots,x_n]$ are UFDs? Default behavior of "git push" without a branch specified I'm a little confused about the output I'm seeing in my routing table, particularly the 'metric' column:  $ route -n Kernel IP routing table Destination     Gateway         Genmask         Flags Metric Ref    Use Iface 0.0.0.0         192.168.0.1     0.0.0.0         UG    0      0        0 wlan0 172.16.35.0     0.0.0.0         255.255.255.0   U     0      0        0 vmnet1 192.168.0.0     0.0.0.0         255.255.255.0   U     9      0        0 wlan0 192.168.82.0    0.0.0.0         255.255.255.0   U     0      0        0 vmnet8   According to the man page, metric indicates the 'distance' to the target. I was a little confused about what exactly "target" was. I assumed it was my router (it goes to gateway 0.0.0.0, which then goes to my router at 192.168.0.1). Thus, I expected the metric to be a single hop to my router. However, it's 9! Why is this so number high? How to keep a constant baselineskip when using minipages (or \parboxes)? When a minipage is used to box a text paragraph, the first line of the minipaged text and the last line of the previous text paragraph are closer than two consecutive lines in a standard text paragraph; analogously, the last line of text inside the minipage and the first line of text after the minipage are also closer.  The following MWE illustrates this:  \documentclass{article} \usepackage{lipsum}  \newcommand\Text{Lorem ipsum dolor sit amet, consectetuer adipiscing elit. Ut purus elit, vestibulum ut, placerat ac, adipiscing vitae, felis. Curabitur dictum gravida mauris. Nam arcu libero, nonummy eget, consectetuer id, vulputate a, magna.\textbullet}  \begin{document}  \Text  \noindent\begin{minipage}{\linewidth} \Text \end{minipage}  \Text  \end{document}   How can I guarantee a constant baseline-skip even if minipages (or \parboxes) are used? How to install Google Chrome Intuitively, $\lim\limits_{t\to -\infty}te^t=0$, since $e^t\to 0$ much faster than $t\to -\infty$.   Is there a way to more rigorously compute this? Writing it as $e^t/(1/t)$ seems resistant to l'Hopital's rule. Importing coordinate data from Excel into QGIS I have an Excel file containing data collected over many years as latitude and longitude coordinates for archaeological sites. How can I import it into QGIS as a new layer? Problem with TP-Link TL-WN823N Recently I installed Ubuntu 16.04 but cant get the usb wifi adapter to work properly , can anyone help me?  When wifi adpater is plugged , the lsusb output:  Bus 001 Device 003: ID 2357:0109 Bus 001 Device 002: ID 0e0f:000b VMware, Inc.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub  Bus 002 Device 004: ID 0e0f:0008 VMware, Inc.  Bus 002 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub Bus 002 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub   When wifi adapter is unplugged , the lsusb output:  Bus 001 Device 002: ID 0e0f:000b VMware, Inc.  Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 002 Device 004: ID 0e0f:0008 VMware, Inc.  Bus 002 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub Bus 002 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Assumed True until proven False. The Curious Case of the Vacuous Truth Given two statements, $P$ and $Q$, and the logical connective, $\implies$, the truth table for $P \implies Q$ is:  $$\begin{array}{ c | c || c | }   P &amp; Q &amp; P\Rightarrow Q \\ \hline   \text T &amp; \text T &amp; \text T \\   \text T &amp; \text F &amp; \text F \\   \text F &amp; \text T &amp; \text T \\   \text F &amp; \text F &amp; \text T  \end{array}$$  Lines one and two are quite clear. What is ambiguous is lines three and four.  One explanation as to why $P \implies Q$ is true when $P$ is false, provided by Velleman goes:     Let $P(x)$ be the statement $x&gt;2$ and $Q(x)$, $x^2 &gt; 4$. When $x=3$, $P$ is true, and $Q(x) = 9$ thus $Q$ is true. If $P(x) = 1$ then $Q(x) = 1$ and they are both false. If $P(x) = -3$ then $Q(x) = 9$ and so the statement is true.   This explanation was quite unsatisfactory to me. Looking at Enderton, we have:     For example, we might translate the English sentence, ”If you're telling the truth then I'm a monkey's uncle,” by the formula ($V \implies M$). We assign this formula the value $T$ whenever you are fibbing. In assigning the value $T$, we are certainly not assigning any causal connection between your veracity and any simian features of my nephews or nieces. The sentence in question is a conditional statement. It makes an assertion about my relatives provided a certain condition — that you are telling the truth — is met. Whenever that condition fails, the statement is vacuously true.      Very roughly, we can think of a conditional formula ($p\implies q$) as expressing a promise that if a certain condition is met (viz., that $p$ is true), then q is true. If the condition $p$ turns out not to be met, then the promise stands unbroken, regardless of $q$.   Though a significant improvement over the Velleman explanation, I still feel uncomfortable with it.  Really, it seems we can conjure up as many silly counter-examples as we like, such as:     If pigs can fly, then I can walk on water.   Though following the above truth table, the implication is that my ability to walk on water is true.  After considering it, it seems to me that $\implies$ is only meaningful when $P$ is true, then we can look at it in relation to $Q$. However, if $P$ is false, then we actually know nothing about the relationship between $P$ and $Q$. This would give a truth table of:  $$\begin{array}{ c | c || c | }   P &amp; Q &amp; P\Rightarrow Q \\ \hline   \text T &amp; \text T &amp; \text T \\   \text T &amp; \text F &amp; \text F \\   \text F &amp; \text T &amp; \text ? \\   \text F &amp; \text F &amp; \text ?  \end{array}$$  where the $?$ denotes that given $P$ we actually don't know anything about $ \implies $.  Thus. one way to clear this up would be to assume that $? = T$. Thus the vacuous truth is a "definition of convenience" in a sense.  The above is my take on the matter.  Could someone provide some clarification on the conditional logical connective? Extracting matrix rows when one of its elements is part of a list (without a loop)