"Tab Tree" or "Tabs Tree" (-s at the end)
"A mice problem" vs. "a mouse problem"
Why are my photos not crisp? I use a Canon EOS Rebel T3i (600D) with the kit lens. I have experimented a lot with different settings and modes, but I feel like I have wasted many good shots that could have looked amazing, if only they were a little bit sharper.  I use auto-focus on most of my pictures and make sure to choose the right focus point, but all of my photos are still a little bit out of focus. When I zoom in, I can see that the pixels are not very crisp or well-aligned.  I am not sure if this issue is caused by my equipment or skills. How can I delete a symbolic link? I created a symlink using mklink.  Now I need to change it but I can't figure out how to delete it so I can recreate it correctly. Are there benefits of passing by pointer over passing by reference in C++? What are the benefits of passing by pointer over passing by reference in C++?  Lately, I have seen a number of examples that chose passing function arguments by pointers instead of passing by reference.  Are there benefits to doing this?  Example:  func(SPRITE *x);   with a call of  func(&amp;mySprite);   vs.  func(SPRITE &amp;x);   with a call of  func(mySprite); Dobble card game - mathematical background In  there is a deck of 55 cards. Each of them has 8 symbols on it. There is a total of 50 different symbols and each two cards have one and only one in common.  I am wondering, given a total number of symbols N and a number of symbols on each card K, how do you find the biggest number of cards such that:   on each of those cards there are exactly K of the N symbols, every two cards have one and only one symbol in common. I have created a logo with pen tool in Illustrator but between lines (where they intersect with each other) there is a gap where it gets the color of the background.  Something like this:  (Black color is the background color) - As you can see where the paths join each other there is a kinda dotted black line. I Grouped them but still the same. I converted to jpeg just to be sure it is not only shown like that but same effect.   NOTE: I want to export that logo as SVG file type and use it in the WEB. I tried some solutions given like anti-aliasing in preferences or art optimize when saving for optimization. But still I have same problem. I want to get that logo in SVG and put it on the web where it will display clean without those strange gaps.  How can i get rid of this? How do I go about porting Ubuntu Touch to different devices? Can sudo be reinstalled after being removed? This seems to be a chicken-egg problem. The most common task using sudo is installing and removing software.  sudo apt-get purge &lt;appname&gt;   But sudo itself can be removed.  sudo apt-get purge sudo # Do not run this command on production computers!   This is where the fun comes  ubuntu@ubuntu:~$ sudo bash: /usr/bin/sudo: No such file or directory   Although it's obvious that no person in his right mind will purge sudo (other than me), someone can be fooled to run this command (not directly, in its hex mode, or whatever it's called) or a person could SSH in disguised as tech guru and do the mess.  So is there a way of reinstalling sudo? Smoothing polygons in contour map? Here is a contour map for which all the polygons of levels are available.  Let ask how to smooth the polygons keeping all vertices preserved in their exact locations?    Indeed the contour is made on top of a grid data, you may suggest then to smooth the grid data and hence the resulting contour will be smoother. Note that this is not working as my desire since the smoothing function such as Gaussian filter will remove small packs of data and will change the range of the third variable e.g., the height which are not allowed in my application.    Actually I'm looking for a piece of code (preferably in Python) which can do the smoothing of 2D polygons (any type: convex, concave, self-intersecting etc) reasonably painless (forget pages of codes) and accurate.   FYI, there is  that does this perfectly, but using third party commercial applications is not my choice for this question.        1)    Scipy.interpolate:        As you see the resulting splines (red) are not satisfactory!  2)    Here is the result using the code given in . It is not working well!      3)    To me the best solution should be something like the following figure in which a square is being smoothed gradually by changing only one value. I hope for similar concept for smoothing any form of polygons.       Satisfying the condition that spline passes the points:     4)    Here is my implementation of "whuber's idea" line by line in Python on his data. There are possibly some bugs since the results are not good.         K=2 is a disaster and so for k>=4.   5)    I removed one point in the problematic location and the resulting spline is now identical to whuber's. But it is still a question that why the method does not work for all cases?        6)    A good smoothing for whuber's data can be as follows (drawn by vector graphics software) in which an extra point has been smoothly added (compare with update   4):      7)    See the result from Python version of whuber's code for some iconic shapes:     Note that the method seems doesn't work for polylines. For the corner polyline (contour) green is what I want but got red. This needs to be addressed since contour maps are always polylines although closed polylines can be treated as polygons as in my examples. Also not that the problem emerged in update 4 has not been addressed yet.  8) [my last]    Here is the final solution (not perfect!):        Remember that you will have to do something about the area pointed by stars.  There is perhaps a bug in my code or the proposed method needs further development to consider all situations and to provide desired outputs. Connected graph with colored edges We have connected undirected graph with colored edges in two way (green or blue). And also each vertex have the same number of green and blue edges. How to prove that there are alternate colored (green-blue) path between any two nodes? Food in the Star Wars Universe? Are the foods in the Star Wars Universe the same as ours'? Do they have strawberries or potatoes or something? I know that they might have some food other than the food that we also have, but I'm wondering if they have any food like ours'. How can I prevent inline math formulas from overflowing into the margin? When I compile my document in LaTeX, some formulas in the document in math mode, between $ $, go into the right margin area beyond all the text.  Is there a way to fix this aesthetic problem? I want to run a script to simply change the current working directory:  #!/bin/bash cd web/www/project   But, after I run it, the current pwd remains unchanged! How can I do that? Minimal cut edges number in connected Eulerian graph. I have to prove that Connected graph is Eulerian Graph if and only if the number of edges in minimal cut is even.  Implication from left to right. Well if $G$ is Eulerian Graph then degree of each vertex must be even. It's oblivious if i try to disconnect graph by removing all edges connected to the vertex with minimal degree. But minimal cut can be done also by dividing graph into 2 connected graphs (each graph with more then one vertex) and i have no idea how to deal with it.  Implication from right to left - completly no idea. What is the function represented by the power series $$ \sum_{k=2}^\infty\frac{x^k}{k(k-1)}\quad? $$  It looks like $\dfrac1{1-x}$ but I don't know. Can I change the color of the last selected face? Can I change the color of the last selected face, so that it is the same as the other selected faces?  Here, I've selected the left face then the right face. Note the right face is some sort of checkered or dithered pattern, and just the outline has the nice orange 'selected' color.    Here I've selected the top face, note the right face has now the nice color.    And here I've deselected the top face. Now, both of the remaining selected faces have the nice color. This is the result I'd rather see instead of image 1. Is it OK to reduce the charging current for a Li-ion 18650 battery? I am using NCR18650 batteries with the tp4056 charging module.  When I connect the charger at 2.8&nbsp;V (fully discharged), the tp4056 IC is getting hot at a 1&nbsp;A charge current. Is it OK to reduce this charge current by changing the charge current selecting resistor? So the tp4056 IC heat would be reduced, wouldn't it?  For my application I don't need a quick charge. With a low current, charging time will be increased, but it does not matter for my application.  Will reducing the charge current affect the battery's lifetime? Or will it damage the battery?  I am trying to reduce the heat of the tp4056 IC by reducing the charging current, maybe from 1&nbsp;A to 500&nbsp;mA or less. The 18650 battery never heats for a 1&nbsp;A charge current. What is mirror lockup and what is its primary function? My SLR is equipped with the mirror lockup function. What does it do, and when would I employ such a feature? Basic circuit to keep LED either on or off depending on night/day How can I have a LED either on or off (not in between) depending on night or day with basic electronics? I have created the circuit below, but it only shines and in darkness it dims.    The photo-resistor is about 3kΩ when light shines and about 1MΩ when dark.  I want my LED to shine at night and be off at day.  What is the simplest way I can achieve this? change color of pgfplot bar plot I want to plot two bar plots next to each other. This works without a problem. However both use the first color defined in a pre or selfdefined colorseries. I tried to modify the color manually in the plot, but the color and fill definitions have no effect:  \documentclass[border=5mm]{standalone} \usepackage{pgfplots, pgfplotstable}  \begin{document}  \pgfplotstableread[header=false, col sep=comma]{  1, first item 5, second item }\datatable  \begin{tikzpicture}   \begin{axis}[             ,xbar     ,bar width=2ex, y=3ex     ,enlarge y limits={abs=0.75}     ,ytick={data} % (\empty,data,{coordinate list})     ,yticklabels from table={\datatable}{1}   ]   \addplot table [     ,red!20!black,fill=red!80!white,     y expr=-\coordindex, % Use negative coordinate index as y coordinate     x index=0 % Use first column as x coordinate   ] {\datatable};   \end{axis} \end{tikzpicture}  \end{document}   The plot is still in the default blue. What does the colon in Tikz coordinates mean?