distancias | Formula PHP para calcular distancia entre dos puntos en KMs

When I click on a card element, I want it to clear the canvas and redraw everything except for the card that was clicked on.

The problem is, clicks on some positions clear more than one card, and i I don't know how to fix it. I have been trying to fix it but so far haven't been successful.

I have this problem where I´m given to list of numbers each list for coordinate X and Y and I have to find which of the coordinates is closest to the first coordinate of the list, for that I have the following code:

I am trying to implement the Simulated Annealing (SA) algorithm to solve a random instance of the Traveling Salesman Problem (TSP) in python. In my code, I have a function that computes the total longitude of the tour, given a list with the route and the distance matrix. When I run my code I have the following error related to this function.

UnboundLocalError: local variable 't' referenced before assignment

My code es the following:

I'm trying to plot a mesh with a radial colormapping. That is, I want all the points in a constant radius to have the same color.

I tried this example but this allows me to modify the color on z-direction only, not the three coordinates.

Any help will be appreciated. Thanks.

edit

Here is the code. It calculates de array factor of an Antenna Array

I must read a txt file using scanf and show in console the content. It is neccesary doing that with scanf. Also #lines should be ommited on the output.

I have next txt file:

I'm a student and I'm trying to do this homework, where I need to do the KNN algorith with the Mahalanobis distance as parameter, but for some reason that I can't figure out, my code is not working.

I'm not a R master, actually I know only the basics.

I have some matrixes and operations and I end up with one matrix called "MatrizFinal", which has a number and then an id that goes from 0 to n in order. I want to sort the matrix so the rows are ordered by the minimum value of the numbers (NOT THE ID) (because I will take the minimum values later on so I need the id.

I have 2 matrixes and I want to safe the euclidean distance of each row in an array so afterwards I can work with the data (knn Kneighbours, I use a temporal named K so I can create later a matrix of that array (2 columns x n rows, each row will contain the distance from position n of the array, in this case, k is that n).

I am learning a bit of programming and I am trying to code an Ant Colony algorithm for QAP, the problem is that sometimes I get segmentation fault and when I use valgrind it tells me "Address 0x0 is not stack'd, malloc'd or (recently) free'd". This is the code: