3D track not tracking rotation? I've 3D tracked a scene and the positional tracking is amazing my model is staying exactly where it should be, but then my camera rotates, and for whatever reason instead of the model rotating it just slides sideways. I've set the y-axis, scale, floor, origin and wall and I have at least 20 trackers. What am I doing wrong?
How can I get better results when doing camera motion tracking? Whenever I do camera tracking in Blender the reconstruction is always zooming out or not on the axis. I have a great quality camera, but the end results of the camera tracking always has the model sliding. If you have a solution please tell me.
Difference between processing.runalg() and general.runalg() In the discussion from a question I asked several days ago (), someone suggested that I use general.runalg() instead of processing.runalg() for running QGIS algorithms.    I've now used both, and haven't noticed a difference in either performance or syntax between them.  I'm just wondering what sort of differences there are between these two methods, and which one I should be using. How should we handle downvote retaliation? Performance differences between pipelines and process substitution I tend to use pipelines in my bash scripts over process substitution in most situations, especially in cases of using multiple sets of commands as it seems more readable to do ... | ... | ... over ... &lt; &lt;(... &lt; &lt;(...)).  I'm wondering though why using process substitution is much faster in some situations than using a pipeline.  To test this, I timed two scripts using 10000 iterations of the same attached commands with one using a pipeline and another using process substitution.  Scripts:  pipeline.bash:  for i in {1..10000}; do     echo foo bar |     while read; do         echo $REPLY &gt;/dev/null     done done   proc-sub.bash  for i in {1..10000}; do     while read; do         echo $REPLY &gt;/dev/null     done &lt; &lt;(echo foo bar) done   Results:  ~$ time ./pipeline.bash  real    0m17.678s user    0m14.666s sys     0m14.807s  ~$ time ./proc-sub.bash  real    0m8.479s user    0m4.649s sys     0m6.358s   I know that pipelines create a sub process whereas process substitution creates a named pipe or some file in /dev/fd, but am unclear about how those differences impact performance. Clarification of the "25D" option in ogr2ogr Initializing Manipulator value within DialogInput (version 10.1 only) Rules for the usage of "me" VS. "myself"? What are general guidelines for the use of "me" and "myself"?     Did I describe me or did I describe Maria?   OR     Did I describe myself or did I describe Maria? How to close view windows? Does the word discharge sound more like /dɪstʃɑːʳdʒ/ or /dɪsdʒɑːʳdʒ/? How about exchange or disproportion? Do they sound more like /ɪkstʃeɪndʒ/ or /ɪksdʒeɪndʒ/? /dɪsprəpɔːʳʃən/ or /dɪsbrəpɔːʳʃən/? I know the word student which commonly sounds like /sdjuːdənt/. and the dictionary says its IPA transcription is /stjuːdənt/. My wifi connection doesnt work properly; it stays connected only for around 5 minutes after I turn on the PC. I'm using Ubuntu 16.04.  I've tried   sudo service network-manager restart   which makes no difference  Same with   killall nm-applet &amp;&amp; nm-applet &amp;   After that I tried   sudo gedit /etc/pm/config.d/config   where I insert this string  SUSPEND_MODULES = "drivername logicalchipname"   But since I don't have permission to modify that file I tried to use chmod on it, which led to  but left me still in the same situation.  $ lspci -knn | grep Net -A3; rfkill list 03:00.0 Network controller [0280]: Realtek Semiconductor Co., Ltd. RTL8821AE 802.11ac PCIe Wireless Network Adapter [10ec:8821] Subsystem: XAVi Technologies Corp. RTL8821AE 802.11ac PCIe Wireless Network Adapter [1b9a:2482]  Kernel driver in use: rtl8821ae  Kernel modules: rtl8821ae  0: hci0: Bluetooth  Soft blocked: yes   Hard blocked: no 1: phy0: Wireless LAN   Soft blocked: no    Hard blocked: no   What do you suggest I do? Starting iPhone app development in Linux? I've heard that you need to get a Mac if you want to develop iPhone apps. Is this true?   Is it possible to develop iPhone apps using Linux? If yes, what do I need and where do I download the necessary tools? If $(1), (log_yx), (log_zy), (-15log_xz)$ are in Arithmetic Progression... If $(1), (log_yx), (log_zy), (-15log_xz)$ are in AP then...   (A)$z^3=x$   (B)$x=y^{-1}$   (C)$z^{-3}=y$   (D)$x=y^{-1}=z^3$   (Multiple answers may be correct)   I tried many approaches, one of them being: $1+log_zy=2log_yx$ $log_zz+log_zy=log_yx^2$ $log_z(yz)=log_yx^2$ But the fact that the bases are different is causing the main problem as I don't know how to proceed further. It would be great if anybody could give me a hint for solving such questions. Inconsistent accessibility error with the following c# code. Why? Proper analyses for 2x2 contingency tables So I have multiple questions about the different types of analyses that can be used on a 2x2 contingency table and when different analyses should be used.   To open, I'll note that this stems from my efforts to find the appropriate analyses to run for research using categorical data in a 2x2 contingency table. In my case I have two conditions: control and experimental and within the experimental group there are two items of interest (say, Item A and Item B). In all cases I'm investigating whether an outcome occurs or not: How many experimental participants show the outcome on Item A? How many experimental participants show the outcome on Item B? How many control participants show the outcome? So in addition to comparing Item A with the Control group (A vs. C) and Item B with the Control group (B vs. C), I also want to compare Item A with Item B (A vs. B).   My understanding is that for between-subjects comparisons (e.g., A vs. C   &amp;   B vs. C) a  is traditionally used and that for within-subjects comparisons (e.g., A vs. B) that  is a common choice.   Question 1: is this an accurate understanding of the common choices for statistical tests using 2x2 contingency tables?    My follow-up questions, and where most of my confusion lies, are related to what to do when multiple observed cell counts are low (less than 10). I've explored numerous threads here, the Wikipedia pages for different topics (Yates's correction, Fisher's exact, etc.), a few journal articles, and descriptions in R-packages, but I have found conflicting views.   Some sources indicate that you should use , others say it's out-dated because, in addition to being overly conservative, it was only preferred because the other options were computationally intense.   Others say that you should use , but I've seen additional information suggesting that Fisher's exact test is only appropriate if you know both the row and column totals and that other options (Boschloo, Barnard, etc.) are generally more powerful. However, which of those to use is also not clear.  Finally, even others suggest that the Pearson's $\chi^{2}$ test is appropriate as long as the expected cell counts are not low.   I've seen some indication that these arguments occur for McNemar's test as well (e.g., continuity correction &amp; McNemar's exact test).  Question 2: Is the assumption regarding cell counts about expected cell counts or observed cell counts? If the observed cell counts are low, does that matter to the type of test that should be used?  Question 3: What is an exact test and when should exact tests be used?    In addition to answers to these questions, I would also greatly appreciate any suggestions as to books or articles I can read to learn more about this. Part of my struggle with all of this has been just general difficult finding clear information about these topics and how they relate to one another. Fully charged MacBook Air turns off when power cord removed I have a MacBook Air, 2009, with a recently replaced Apple battery in December 2012. Recently, when power cord comes off, the computer shuts down. Also, it usually will not restart unless power cord is attached. Changing Vim indentation behavior by file type Could someone explain to me in simple terms the easiest way to change the indentation behavior of Vim based on the file type? For instance, if I open a Python file it should indent with 2 spaces, but if I open a Powershell script it should use 4 spaces. 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. How to execute a JavaScript function when I have its name as a string I have the name of a function in JavaScript as a string. How do I convert that into a function pointer so I can call it later?  Depending on the circumstances, I may need to pass various arguments into the method too.  Some of the functions may take the form of namespace.namespace.function(args[...]). Unexpected workspace change? My friend who has only recently downloaded blender has come across a workspace issue. He said he accidentally pressed a button and it has entirely changed his user interface/ Workspace. He can't open, save or do anything with the change.    This is a full window image! How to create a hole in a polygon in QGIS? I'm trying to use the tool "delete ring" in order to create a hole in a polygon. The geometry of the hole is another feature of the same shapefile   I cannot manage to delete the part of the polygone. Does someone have a tutorial or some explanation? SF TV show about a war between humans and aliens?