I have a file in QGIS with 5000 points. Some of the points are really close to each other (5m). How can I cluster the point features to one point feature if they are within 5m? The new points should be centroids from the given points.
I have a vector file containing thousands of points. Where points are within x distance from each other, I wish to delete one of the points and keep the other (either by snapping to one point, or simply erasing one of the two points)  However, in Whitebox the vector cleaning tool only works with polygons and lines.  Is there some other way I can do this with my shapefiles?
induction with 2 recursive sequnces I'm having trouble solving this problem. I have relation for two sequences of natural numbers.   $$a(n)+\sqrt3\cdot b(n)=\left(1+\sqrt3\right)^n$$  and I have to prove that recursions:  $$\begin{align*} &amp;a(n+1)=a(n)+3b(n)\\ &amp;b(n+1)=a(n)+b(n) \end{align*}$$  will satisfy relation mentioned above. I tried solve it using induction but I failed. Can anybody help with some other ideas? Convert from MySQL datetime to another format with PHP I have a datetime column in MySQL.   How can I convert it to the display as mm/dd/yy H:M (AM/PM) using PHP? GParted won't let me edit a partition Is the Echo of a Echo Knight actually a creature? I've always been certain that the echo created by an Echo Knight fighter using their 3rd-level feature Manifest Echo is not defined in game terms as a creature, since the description of the echo never explicitly tells it is a creature. But the presence of people believing the echo to be a creature in lieu of the fact that it is immune to all conditions and might make saving throws (game characteristics typically associated with creatures only) brought this doubt to my mind.  from Jeremy Crawford implies it is just an image and not a creature, further confirming that the feature should tell you, but  implies that the echo is an object whilst the feature doesn't explicitly say so. (Included for reference and insight, since tweets are not eligible as official ruling) Is the echo a creature? WebView loading Url bashrc lazy substitution Custom cross-reference formats (e.g. "Equation 1" instead of just "1") What are the main differences between performing principal component analysis (PCA) on the correlation matrix and on the covariance matrix? Do they give the same results? What to do with random effects correlation that equals 1 or -1? Not so uncommon occurrence when dealing with complex maximal mixed models (estimating all possible random effects for given data and model) is perfect (+1 or -1) or nearly perfect correlation among some random effects. For the purpose of the discussion, let's observe the following model and model summary   Model: Y ~ X*Cond + (X*Cond|subj)  # Y = logit variable   # X = continuous variable   # Condition = values A and B, dummy coded; the design is repeated  #             so all participants go through both Conditions   # subject = random effects for different subjects    Random effects:  Groups  Name             Variance Std.Dev. Corr               subject (Intercept)      0.85052  0.9222                              X                0.08427  0.2903   -1.00                      CondB            0.54367  0.7373   -0.37  0.37                X:CondB          0.14812  0.3849    0.26 -0.26 -0.56 Number of obs: 39401, groups:  subject, 219  Fixed effects:                  Estimate Std. Error z value Pr(&gt;|z|)     (Intercept)       2.49686    0.06909   36.14  &lt; 2e-16 *** X                -1.03854    0.03812  -27.24  &lt; 2e-16 *** CondB            -0.19707    0.06382   -3.09  0.00202 **  X:CondB           0.22809    0.05356    4.26 2.06e-05 ***   The supposed reason behind these perfect correlations is that we have created a model which is too complex for the data that we have. The common advice that is given in these situations is (e.g., Matuschek et al., 2017; ) to fix the overparameterized coefficients to 0, because such degenerate models tend to lower the power. If we observe a marked change in fixed effects in a reduced model, we should accept that one; if there is no change, then there is no problem in accepting the original one.  However, let's presume that we are not interested only in fixed effects controlled for RE (random effects), but also in the RE structure. In the given case, it would be theoretically sound to assume that Intercept and the slope X have non-zero negative correlation. Several questions follow:   What to do in such situations? Should we report the perfect correlation and say that our data is not "good enough" to estimate the "real" correlation? Or should we report the 0 correlation model? Or should we maybe try to set some other correlation to 0 in hope that the "important" one will not be perfect anymore? I don't think there are any 100% correct answers here, I would mostly like to hear your opinions. How to write the code which fixes the correlation of 2 specific random effects to 0, without influencing the correlations between other parameters? Calculation of $\int^{\pi/2}_{0}\cos^{n}(x)\cos (nx)\,dx$, where $n\in \mathbb{N}$ Compute the definite integral      $$ \int^{\pi/2}_{0}\cos^{n}(x)\cos (nx)\,dx $$      where $n\in \mathbb{N}$.   My Attempt:  Using $\cos (x) = \frac{e^{ix}+e^{-ix}}{2}$, we get  $$ \begin{align} \int^{\pi/2}_{0}\cos^{n}(x)\cos (nx)\,dx&amp;=\int_{0}^{\pi/2} \left(\frac{e^{ix}+e^{-ix}}{2}\right)^n\left(\frac{e^{inx}+e^{-inx}}{2}\right)\,dx\\ &amp;= \frac{1}{2^n}\mathrm{Re}\left\{\int_{0}^{\pi/2} \left(e^{ix}+e^{-ix}\right)^n\cdot e^{inx}\,dx\right\}\\ &amp;=\frac{1}{2^n}\mathrm{Re}\left\{\int_{0}^{\pi/2}\left(e^{2ix}+1\right)^n\,dx\right\} \end{align} $$  Letting $z=e^{4ix}$ gives us  $$ \begin{align} e^{4ix}dx &amp;= \frac{1}{4i}dz\\ dx &amp;= \frac{dz}{4iz} \end{align} $$  So the integral becomes  $$\frac{1}{4\cdot 2^n}\mathrm{Re}\left\{\int_{C}\left(\sqrt{z}+1\right)\cdot \frac{dz}{iz}\right\}$$  How can I complete the solution from here? I am learning Linux and I was trying the gzip command. I tried it on a folder which has a hierarchy like  Personal/Folder1/file1.amr Personal/Folder2/file2.amr Personal/Folder3/file3.amr Personal/Folder4/file4.amr   I ran     "gzip -r Personal" and now its like  Personal/Folder1/file1.amr.gz Personal/Folder2/file2.amr.gz Personal/Folder3/file3.amr.gz Personal/Folder4/file4.amr.gz   How do I go back? I have a professor at my university who uses content from an un-cited textbook that he has never referenced anywhere, including his green sheet (syllabus), as an additional resource. At least some slides he has used include parts of content that have been re-worded and others that are 100% the same. I noticed this by Googling for textbooks on the material we're studying in class and found that examples given in one that I found were exactly the same as what he has provided.  Would this technically be plagiarism? Should he be given the benefit of the doubt in this situation? simple process builder failing with error "failed to access the value for variable because it hasn't been set or assigned" Note: This error might look like a familiar error but the   resolution mentioned in the  is not working in the below case and I am not sure why, hence posting this question.   Problem description:   I have a process builder on case object set to fire for every time new record is created. Criteria is set to 'Formula evaluates to True' with below formula: AND(NOT(ISBLANK([Case].AccountId)),ISPICKVAL([Case].Account.Active__c,'Yes')) With immediate action set to update custom field on the Case object. Custom field Active__c on the Account object is type picklist with two possible values 'yes' and 'no'.   Screenshots of the process builder:        Creating a case as shown in the below screenshot with very minimal details and especially not populating account details:    Throws below error:     The flow failed to access the value for   myVariable_current.Account.Active__c because it hasn't been set or   assigned.   Relevant data from log file:     22:14:31.0 (12479016)|WF_FLOW_ACTION_BEGIN|09L370000000FEJ 22:14:31.13   (13607478)|FLOW_CREATE_INTERVIEW_BEGIN|00D37000000H8hr|300370000008ZTl|301370000004weE   22:14:31.13   (15394571)|FLOW_CREATE_INTERVIEW_END|5525dfa7819c33f438ce3cef9b6c15c668d8ff2-3d11|Test   22:14:31.15 (15820974)|FLOW_START_INTERVIEWS_BEGIN|1 22:14:31.15   (16674702)|FLOW_START_INTERVIEW_BEGIN|5525dfa7819c33f438ce3cef9b6c15c668d8ff2-3d11|Test   22:14:31.15 (35470120)|FLOW_ELEMENT_ERROR|The flow failed to access   the value for myVariable_current.Account.Active__c because it hasn't   been set or assigned.|| 22:14:31.15   (35479812)|FLOW_START_INTERVIEW_END|5525dfa7819c33f438ce3cef9b6c15c668d8ff2-3d11|Test 22:14:31.15 (35517783)|FLOW_START_INTERVIEWS_END|Interview error.   Aborting all.|5525dfa7819c33f438ce3cef9b6c15c668d8ff2-3d11|Test   22:14:31.15 (35528335)|FLOW_START_INTERVIEWS_END|1 22:14:31.0   (35588898)|WF_FLOW_ACTION_ERROR|09L370000000FEJ|300370000008ZTl|Error   executing flow: test, FlowDefId: 300370000008ZTl, FlowVersionId:   301370000004weE 22:14:31.0   (35612585)|WF_FLOW_ACTION_ERROR_DETAIL|An unhandled fault has   occurred in this flowAn unhandled fault has occurred while   processing the flow.  Please contact your system administrator for   more information. 22:14:31.0   (35683203)|WF_FLOW_ACTION_END|09L370000000FEJ   URL to the complete debug log :  (Note: You can see from the log that there are no other workflow rules or triggers on the case object).  My analysis: When the first condition inside the AND expression is evaluating as false, why is it trying to evaluating the second condition to check the custom field on the Account object? It shouldn't right?  Any help?  EDIT: I am looking to solve this using option 'Formula Evaluates to True' only because I have other complex criteria like checking the day(Mon vs Tue and etc) of the case creation. Uniform Scattering with vector How soon can I re-enter the USA having stayed for 90 days under the Visa Waiver Program? I am currently visiting the USA from the UK (I am a UK citizen) and am intending on staying here for the full 90 days under the Visa Waiver Program.     How long would I have to stay out of the US at the end of this period before returning again?    Would I have to return to the UK, or could I stay with friends in another country (such as Canada) for a while? How to get this only in small letters (lowercase)? I used the following code to give out the category name (without link) in a single post.  How would it be possible for the category name that is given out to only appears in small letters ?  I just think this has to be made with substring, but I dont get it :) Could somebody please help me :)  &lt;?php foreach((get_the_category()) as $category) { echo $category-&gt;cat_name . ' '; } ?&gt; Can ovulation and menstruation occur simultaneously? Is that possible that ovulation happens in the time of actual menstrual haemorrhage in human females - let say in a case that woman has 21 day cycle and her menstrual period is 7 days?   If yes, does it means that in this particular case the woman has lower chances to conceive? Removing unnecessary vertices? I have over sampled polygons that I need to simplify, without changing the shape. basically, I want to reduce the number of vertices, by eliminating the ones that are useless and have the polygons represented with the significant vertices only. I used to do that with ET GeoWizards Plug-in, but I don't have a license anymore. My table has 500.000 features, water polygons.   Any ideas? Power failure during upgrade During upgrade from 12.04 to 12.10 there was a power failure.  computer boots to desktop but without tools and menus to navigate.  files that can be open cannot be closed.  sidebar menu does not exist.  there is no function of the DVD drive, the USB drive nor the internet.  Possible to open GRUB but I am not familiar with it's function.  Please help. Do numbers exist independently from observers?