I wonder if there is any rule for doubling the p at the end of a stem. For example:     stop — stopped   but      help — helped
Initially, my question was: is "focussed" or "focused" the correct past tense of "focus", but since this applies to a lot of words, I would like to generalize and ask: is there supposed to be a rule when to double the consonant?
An English book tells me that the following sentence is correct:     This publication is made from paper from sustainable forests.   Shouldn't it be of paper instead? How do you file a bug report for Windows? I have come across an issue that I feel is a  in Windows 7. What is the official process for submitting an issue to Microsoft from a consumers perspective as an end user of Windows? I have requested for a French long term (Type D) student visa from a consulate in India. It's a national Type D visa and not a Schengen visa. My question is that can we still go to other Schengen countries on this visa? If not then can we get a Schengen visa from a consulate in France? Why is quantum entanglement considered to be an active link between particles? How to make the taskbar blink my application like Messenger does when a new message arrive? Tikz won't plot the function properly I tried to plot the following function but it didn't work:  y = 300 + 1000/x + 2.5x.  This is the document, but instead of the plot it only shows the axis.  \documentclass{article}  \usepackage{pgfplots}% This uses tikz \pgfplotsset{compat=newest}% use newest version  \pgfmathdeclarefunction{Function}{1}{%   \pgfmathparse{300 + 1000/x + 2.5}% }  \tikzset{My Line Style/.style={smooth, thick, samples=400}}  \begin{document} \begin{tikzpicture} \begin{axis}[     xmin=0.0,     xmax=250,     ymin=0,     ymax=50,     axis x line=bottom,     axis y line=left,      xlabel= $y$,     ylabel=Cost,      xtick={250},     xticklabels={250},         restrict x to domain=0:250,     ]        \addplot+[My Line Style, color=black, samples at={1,2,3,4,...,249,250}] (\x,{Function(\x)});   \end{axis}  \end{tikzpicture} \end{document} \documentclass{article} Determining if a game is CPU- or GPU-limited What is a reliable, but not too time-consuming way to determine if a certain game is limited by the graphics card or by the processor speed?  I have some preconceptions about whether I'm mostly GPU or CPU limited, but I'd like to verify if I'm right about that. I have some ideas how I would go around and test that but performing accurate benchmarks is notoriously tricky and I don't have much experience with it.   So I'm wondering what would be an easy way to determine the bottleneck, having only one computer with a certain configuration available? What tools would I use for that purpose?  It would also be interesting to determine if the amount of VRAM on my graphics card is a limiting factor. Brackets in if condition: why am I getting syntax errors without whitespace? Suppose I have 30 numbers that vary between 0 and 1.0 and which sum to 1.0.  The mean is obviously 0.033.  A client wants these scaled to lie between 0 and 1.0 but to have a mean of 0.5.  By the way, I'll probably have to do this for any set of numbers (positive, negative, outside the range 0 - 1) so that they lie in the range 0 - 1 and have a mean 0.5.  Any suggestions? How Many Genius Mixes Are There in iTunes? 1) Up until now, during practical work sessions, I always used these formulas for uncertainty propagation:  if $C = A+B$  or  $C = A-B$ $$\Delta C = \Delta A + \Delta B$$ if $C = AB$ or $C = \frac{A}{B}$ $$\frac{\Delta C}{C} = \frac{\Delta A}{A}  + \frac{\Delta B}{B}$$ if $C = A^m$ $$\frac{\Delta C}{C} = |m|\frac{\Delta A}{A}$$   These formulas are derived from the expression for the differential of a function of multiple variables:  if $C = f(A,B)$ $$ dC = \frac{\partial C}{\partial A}dA + \frac{\partial C}{\partial B}dB \Rightarrow \Delta C = \frac{\partial C}{\partial A}\Delta A + \frac{\partial C}{\partial B}\Delta B$$  and I think that makes sense because the value C is just a function of two variables that happen to be measurements.  2) But this morning, I was told that this is wrong and I should actually use these instead:  if $C = A+B$  or  $C = A-B$ $$(\Delta C)^2 = (\Delta A)^2 + (\Delta B)^2$$ if $C = AB$ or $C = \frac{A}{B}$ $$\left(\frac{\Delta C}{C}\right)^2 = \left(\frac{\Delta A}{A}\right)^2  + \left(\frac{\Delta B}{B}\right)^2$$  which are apparently derived from a general formula:  $$(\Delta C)^2  = \left(\frac{\partial C}{\partial x_1}\Delta x_1\right)^2 + \left(\frac{\partial C}{\partial x_2}\Delta x_2\right)^2 +   \hspace{0.3cm}...$$  or   $$\Delta C  = \sqrt{\left(\frac{\partial C}{\partial x_1}\Delta x_1\right)^2 + \left(\frac{\partial C}{\partial x_2}\Delta x_2\right)^2 +   \hspace{0.3cm}...}$$  3) So:   Why is this formula better?  Where does it come from? What does it actually represent? (Do I recognize the shape of a norm in that last formula?)  What is wrong with the formula of the differential?   I'm asking a lot, but the propagation of uncertainty always confused the ship out of me. Suppose that a box contains 10 red balls, 20 green balls, and 30 blue balls.   Suppose also that balls are drawn from the box one at a time at random.  What is the probability that all the red balls are drawn before the blue or green balls are themselves exhausted. What is the probability that as the last red ball is drawn, there remains at least one blue and one green left in the box.  The answer I was given is $\dfrac{7}{12}$ and a general equation is: $$ \dfrac{b g}{1-b}+\dfrac{b g}{1-g} $$ where $$ g=\dfrac{20}{60},b=\dfrac{30}{60} $$ but why? How to use a decimal range() step value? Is there a way to step between 0 and 1 by 0.1?   I thought I could do it like the following, but it failed:  for i in range(0, 1, 0.1):     print i   Instead, it says that the step argument cannot be zero, which I did not expect. Black flakes from new cast iron pan I bought a brand new Lodge 12" cast iron pan, washed it in soap and warm water and dried it with a paper towel thoroughly. Then I applied a thin layer of canola oil with a paper towel (paper towel was clean - not black after this application) and then heated the empty pan on my electric stove for 15-20 minutes. The oil on the pan smoked a bit, some parts of the pan turned slightly ashy (grey). Mostly everything looked OK.   After I turned it off and cooled the pan, I now take a clean paper towel and rub the surface and I see black flakes! What is this? Is this the oil broken down? Can I cook in the pan or wash it with soap to eliminate the black flakes? Once washed and dried should I rub canola oil again? This is my first experience with cast iron. Any pointers will help. Looking for solo (one person) RPGs - do they exist? I am looking to find out if solo RPGs exist, and which you'd recommend.  I do not mean "one-on-one" 1 player + 1 GM games. I really mean "1 person."  Update: After receiving two (fine, up-voted) answers that indicate Choose Your Own Adventure solutions (which rocks with nostalgia), I should add that I'm not looking for simple linear decision tree gaming. A counterexample: I've got my own little creative-writing mini-game where I write out a story, but once every 5 sentences a series of dice-rolls forces my written sentence into something else, and I have to adapt as writer. Not really an RPG, but also non-linear. remote action function encountering CPU time out limit exception Fake a webcam using a video loopback device? I want to use a looped video clip as my webcam source in a Google+ Hangout. I installed v4l2loopback and created a . But I haven't figured out how to write the video frames to the device. The given  is:  gst-launch videotestsrc ! v4l2sink device=/dev/video1   So after reading the manual page for gst-launch and trying to understand what was going on, I made my feeble attempt:  sudo gst-launch-0.10 filesrc location=/home/briankb/Videos/darthvaderdancing.mp4 ! v4l2sink device=/dev/video0   Which resulted in:  Setting pipeline to PAUSED ... libv4l2: error getting pixformat: Invalid argument Pipeline is PREROLLING ... Pipeline is PREROLLED ... Setting pipeline to PLAYING ...  (gst-launch-0.10:12622): GStreamer-CRITICAL **: gst_caps_get_structure: assertion `GST_IS_CAPS (caps)' failed New clock: GstSystemClock  (gst-launch-0.10:12622): GStreamer-CRITICAL **: gst_structure_get_name: assertion `structure != NULL' failed Caught SIGSEGV accessing address (nil) #0  0x00007fc1890f0b03 in poll () from /lib/x86_64-linux-gnu/libc.so.6 #1  0x00007fc18962bff6 in ?? () from /lib/x86_64-linux-gnu/libglib-2.0.so.0 #2  0x00007fc18962c45a in g_main_loop_run () #3  0x00007fc189b5c4cb in gst_bus_poll () #4  0x0000000000404587 in ?? () #5  0x0000000000403c34 in ?? () #6  0x00007fc18902b76d in __libc_start_main () #7  0x00000000004043bd in ?? () #8  0x00007fff88253ed8 in ?? () #9  0x000000000000001c in ?? () #10 0x0000000000000006 in ?? () #11 0x00007fff882548c4 in ?? () #12 0x00007fff882548d4 in ?? () #13 0x00007fff882548dc in ?? () #14 0x00007fff88254904 in ?? () #15 0x00007fff88254906 in ?? () #16 0x00007fff8825490f in ?? () #17 0x0000000000000000 in ?? () Spinning.  Please run 'gdb gst-launch 12622' to continue debugging, Ctrl-C to quit, or Ctrl-\ to dump core.   The clip I'm trying to use an h264 video at 29.97 fps, 320x240, and in an mp4 container (it's from Youtube). I know that I can append &amp; to a command to run the process in the background.   I'm SSH'ing into an Ubuntu 12.04 box and running a python program with $python program.py &amp; -- but when I go to close the terminal window I get a message saying that closing the terminal will kill the running process.   Why is this? I am using the ampersand to run the process in the background. How can I get it to run regardless of if I am SSH'ed in? Are PS+ free games region-locked? I have a PSN account that belongs to region X. It has a PS+ subscription. I have acquired many games throughout the years; some are PS+ free games, some are digital medias bought from PS Store. I'm moving to region Y.   Question: will I be able to play all of them normally on while I'm in region Y, specially those free PS+?  In other words, will I be able to keep using the same PSN and PS+ accounts and get access to my games in the library?  PS: I believe it is not possible to change country of a PSN account, isn't that so? Accessing bpy.context gives a '_RestrictContext' warning, how to fix this?