I have a scene with some objects. Lamps, modelled stuff and imported 3ds objects.  When i try to rotate the 3d View via middlemouse, the pivotpoint is never inside the selected object. It always sits at the middle of the screen.  Is there a way to force blender to pivot around the selected object ? Pivot Point settings imply that you can easily tell blender where the pivotpoint should sit. But if i use it nothing changes.  Things i already tried: I reset the origin. I tried all Pivot Point Settings. I applied Rotation and Scale. I looked for already asked questions and answers but none of them helped.  What is it im doing wrong ? Is there a simple solution and im just stupid ?
I was working quickly, (making mistakes), and suddenly rotation and scale transforms stopped working. I think I hit some shortcut or button by accident. Translate still works though. I checked that the transforms weren't locked and such, to no avail. What could be the cause?
How do I fix a "Problem with MergeList" or "status file could not be parsed" error when trying to do an update? The computer gave me this output in a window:  E: Encountered a section with no Package: header E: Problem with MergeList /var/lib/apt/lists/archive.ubuntu.com_ubuntu_dists_natty_main_binary-i386_Packages E: The package lists or status file could not be parsed or opened.   How can I fix this? How can I install software or packages without Internet (offline)? Lets assume my classes are loaded from a compressed .war file or loaded elsewhere,  how can I discover all the resources in a given package?  Enumerating files will not really work, since this is a war file.  Most likely this will involve using the current classloader?  Is there a library out there that does something like that? Googling revealed only some hacks with listing files. Why is compactness so important? I've read many times that 'compactness' is such an extremely important and useful concept, though it's still not very apparent why. The only theorems I've seen concerning it are the Heine-Borel theorem, and a proof continuous functions on R from closed subintervals of R are bounded. It seems like such a strange thing to define; why would the fact every open cover admits a finite refinement be so useful? Especially as stating "for every" open cover makes compactness a concept that must be very difficult thing to prove in general - what makes it worth the effort?  If it helps answering, I am about to enter my third year of my undergraduate degree, and came to wonder this upon preliminary reading of introductory topology, where I first found the definition of compactness. notify-send not working under ssh I'm looking for a formula to calculate the sum of $(a+b+c+d+...)^n$ but with coefficients equal to 1. For example in $(a+b+c)^2$. I want the sum of $a^2 + b^2 + c^2 + ab + bc + ca$. And for $(a+b+c+d)^3$, I want the sum of $a^3 + b^3 + c^3 + a^2b + a^2c + b^2a + b^2c + c^2a + c^2b + abc$. Similarly, I want the sum of expansion of $(a+b+c+d+e+....)^n$ with coefficient equal to 1. I tried to find the pattern by expanding the $(a+b+c)^2$. And I found that its formula is $a^2 + b^2 + c^2$ + $\frac{((a+b+c)^2 - a^2-b^2-c^2)}{2}$. This works for the power of 2. But fails on other powers. Any help will be really appreciated. Enable HTML5 tags on Eclipse I really love Eclipse (PDT)... But i'm developing sites using HTML5 and CSS3 and it mark the HTML5 tags like &lt;nav&gt;, &lt;section&gt; and &lt;article&gt;  as invalid tags (inexistent).  How can I add those new tags to it?  And what about CSS3 rules?  I read something about remove the "invalid tag" check... and that's not what I want. :( I am trying to take pictures of large rugs. The rug size is about 10mx5m, and I'm  planning to purchase , and Canon 7D Mark II with Canon EF 50MM F/1.2L USM lens, since we need high quality images.  We want to set up a studio to take giga-pixel quality images of the large rugs for museum conservation purposes  Could you please suggest the best way for mounting the camera to the ceiling, and any other recommendations for my camera/lens setup, and required lighting? It will be  an indoor shoot. Just we want to setup a studio to shoot the large rugs. How can I expand a partition into non adjacent free space using GParted? Given:  DateTime.UtcNow   How do I get a string which represents the same value in an -compliant format?  Note that ISO 8601 defines a number of similar formats. The specific format I am looking for is:  yyyy-MM-ddTHH:mm:ssZ What is this strange function definition syntax in C? How many ways can we let people into a movie theater if they only have half-dollars and dollars? My interest in combinatorics was recently sparked when I read about the many things that the Catalan numbers count, as found by Richard Stanley. I picked up a copy of Brualdi's Combinatorics, and while browsing the section on counting sequences I found a nice little puzzle that has definitely puzzled me.     Let $m$ and $n$ be nonnegative integers with $n\geq m$. There are $m+n$ people in line to get into a theater for which admission if $50$ cents. Of the $m+n$ people, $n$ have a $50$-cent piece and $m$ have a $\$ 1$ dollar bill. The box offices opens with an empty cash register. Show that the number of ways the people can line up so that change is available when needed is   $$ \frac{n-m+1}{n+1}\binom{m+n}{m}. $$     I first noted that the first person to enter must be one of the $n$ with a half-dollar. Now the register has a half-dollar change. The second person can be either a person with a half-dollar or a dollar. In the first case, the register will now have two half-dollars, in the second case, the register will now have one dollar bill. So it seems to me that when one of the $n$ people with a half-dollar enters, the number of half-dollars in the register increases by $1$, and when one of the $m$ people with a bill enters, the number of half-dollars decreases by $1$ but the number of bills increases by $1$.   I tried to model this by looking at paths in $\mathbb{Z}^2$. The $x$-axis is like the number of half-dollars, and the $y$-axis is the number of bills. You start at $(0,0)$, and you can take steps forward $(1,0)$ or backwards diagonally $(-1,1)$ corresponding to who enters, but you must always stay in the first quadrant of the plane without crossing over the axes. The goal is to make $m+n$ moves, and I figured maybe the number of such paths is counted by $\frac{n-m+1}{n+1}\binom{m+n}{m}$, but I'm not sure how to show this. I don't know if this observation simplifies the problem at all, as I don't know how to finish up. I'd be happy to see how this problem is done, thank you. Desktop link to Eclipse How to make a complaint about grades? My professor announced the grades. He told us in each part what grades we had. My oral presentation for the project was way better than other students. But he just gave me 89 for oral and gave others 88.  I think it is not fair at all, because most of the students were not clear or the did not consider timing. He also told me that "your presentation was very good".  Also, I performed very well on the final exam but he also did not give me the 100. I think it is not fair.  How can I make a complaint? What should I write? Regular Expression to match valid dates I'm trying to write a regular expression that validates a date.  The regex needs to match the following   M/D/YYYY MM/DD/YYYY Single digit months can start with a leading zero (eg: 03/12/2008) Single digit days can start with a leading zero (eg: 3/02/2008) CANNOT include February 30 or February 31 (eg: 2/31/2008)   So far I have   ^(([1-9]|1[012])[-/.]([1-9]|[12][0-9]|3[01])[-/.](19|20)\d\d)|((1[012]|0[1-9])(3[01]|2\d|1\d|0[1-9])(19|20)\d\d)|((1[012]|0[1-9])[-/.](3[01]|2\d|1\d|0[1-9])[-/.](19|20)\d\d)$   This matches properly EXCEPT it still includes 2/30/2008 &amp; 2/31/2008.  Does anyone have a better suggestion?  Edit: I found  on RegExLib  ^((((0[13578])|([13578])|(1[02]))[\/](([1-9])|([0-2][0-9])|(3[01])))|(((0[469])|([469])|(11))[\/](([1-9])|([0-2][0-9])|(30)))|((2|02)[\/](([1-9])|([0-2][0-9]))))[\/]\d{4}$|^\d{4}$   It matches all valid months that follow the MM/DD/YYYY format.  Thanks everyone for the help. I just read a book "Linear Algebra and Its Applications 4E" by David C. Lay. The book is (should be) LaTeX typeset. The matrix and equations are so nice, please see the following 3 examples:        It's so beautiful, so I want get the same effect inside my paper. Here is my code:   \usepackage{amsmath} \usepackage{colortbl} \newcommand\y{\cellcolor{clight2}} \definecolor{clight2}{RGB}{212, 237, 244}%  %%% \[A=\left[ \begin{array}{ccccc} \y 0 &amp; -3 &amp; -6 &amp; 4 &amp; 9 \\    -1 &amp; \y -2 &amp; -1 &amp; 3 &amp; 1 \\ -2 &amp; -3 &amp; 0 &amp; \y 3 &amp; -1 \\ 1 &amp; 4 &amp; 5 &amp; -9 &amp; -7      \end{array} \right]\]  \[A=\left[\begin{array}{cccccc} \rowcolor{clight2} 3 &amp; -9 &amp; 12 &amp; -9 &amp; 6 &amp; 15\\ 0 &amp; 2 &amp; -4 &amp; 4 &amp; 2 &amp; -6 \\ 0 &amp; 3 &amp; -6 &amp; 6 &amp; 4 &amp; -5 \end{array} \right]\]   And the result:     But how to add these arrows?? Proving the two given vectors are orthogonal I am given the vectors $\mathbf{w}, \mathbf{v}, \mathbf{u}$ in $\mathbb{R}^n$ such that $\mathbf{u} \neq 0$ and $\mathbf{w} = \mathbf{v} - \frac{\mathbf{u}\,\bullet\,\mathbf{v}}{\|\mathbf{u}\|^2}\bullet\mathbf{u}$. I am asked to show that the vector $\mathbf{w}$ is orthogonal to $\mathbf{u}$.     So far, I have written out the definition of orthogonal: two vectors are orthogonal if and only if their dot product is zero.   So what we need to prove is $\mathbf{w}\bullet\mathbf{u} = 0$ where $\mathbf{w}\bullet\mathbf{u}$ is defined as $\mathbf{w}^T\bullet\mathbf{u}$.   However, I have been stuck on this problem for about an hour and haven't made any significant progress from here. How do we go about proving that the vectors are orthogonal? I am trying to perform stepwise regression for variable selection in R.  In matlab, the stepwisefit function is able to work in n &lt; p problems. Trying to use step() for such problems i get the error message AIC is -infinity for this model, so 'step' cannot proceed. Is there a way to modify parameters so i can use step function? As you can see in object mode there are 4 vertices that have separated the front of the cartridge into multiple faces when I use boolean modifiers on cartridge.001. How can I fix this?  I imagine it has to do with good topology.  Here's the cartridge in object mode showing faces:    Here is the cartridge with the unwanted vertices:    Attached is the .blend I need to build a probabilistic cellular automaton for simulating land-use changes and am wondering how to implement this in a GIS. I understand that Markov chains are a way of doing this, and IDRISI has some sort of module for Markov chains, but I have no access to IDRISI.  that, with raster data, this can, in theory, be done with any GIS that can do raster algebra. Presumably this means that it can even be done in ArcGIS, and I think I've figured out how to build cellular automata in ModelBuilder (once I know with certainty how to make iteration work there).  Still, I can find next to no practical advice on this. Once I have two datasets, one showing the land use at a certain point in time (time A) and the other at a later time (time B), I imagine doing the following (correct me if I'm wrong):   If there are (for example) 3 types of land use, then there are 9 possible things that can happen to a cell from time A to time B; thus, reclassify each dataset such that each land use is represented by a different number (for example, 9, 11, and 14 at time A and 3, 4, and 5 at time B); Divide one raster by the other, obtaining a raster with 9 possible cell values. Determine the percentage of cells in the new raster that has each of the 9 values (I forgot, how does one do this in ArcGIS?); those will be the probabilities of each type of change (or lack thereof) in land use.   What I cannot figure out, though, is how to apply these probabilities during the next iteration. Finally, I wonder if there is a way of making an external factor (say, proximity to roads) influence the spatial distribution (not the overall likelihood) of change in my model.  Can anyone recommend where to find information on how to do this in ArcGIS?