belisarius
Reputation
98/100 score
 Mar 13 comment DSolve giving strange error messages solving a PDE I wonder what form has that f in the "general" solution ... Can you share some info about it? Mar 13 comment How can I compare two iteration results and define error? Mar 13 revised How can I compare two iteration results and define error? added 62 characters in body Mar 13 comment How can I change this function for the better? But you already know how to search the internet.... This question is a dup. Mar 12 comment mixing color of individual parts of a function in DensityPlot I expected a gray scale from black to white for f[x_, y_] := {Sin[x], Sin@x, Sin@x}. It seems I have scaling issues. Mar 12 reviewed Close Function to find minimum element in array Mar 12 comment mixing color of individual parts of a function in DensityPlot @DavidG.Stork mathematica does not inject the coordinates into the ColorFunction. Only the function value, and that is not enough for what the OP wants to achieve Mar 12 reviewed Close Exporting pdf with a precise page dimension in metric units, rather than printer points Mar 12 reviewed Close Can I name a variable as D(1,0,+1/2)? Mar 12 comment Can I name a variable as D(1,0,+1/2)? You're looking for trouble. Mar 12 comment Can I name a variable as D(1,0,+1/2)? Welcome to Mathematica.SE! I suggest the following: 0) Browse the common pitfalls question 1) As you receive help, try to give it too, by answering questions in your area of expertise. 2) Read the faq! 3) When you see good questions and answers, vote them up by clicking the gray triangles, because the credibility of the system is based on the reputation gained by users sharing their knowledge. Also, please remember to accept the answer, if any, that solves your problem, by clicking the checkmark sign! Mar 12 reviewed Close 3D Plot for Attractive and Repuslive Field Functions Mar 12 revised Matrix of boundary distance between countries added 1025 characters in body Mar 12 comment Matrix of boundary distance between countries @ivanmp Each separate territory in a country (for example an island) gives you a polygon in CountryData["xxx", "Coordinates"]. In my example I considered only one polygon for each country to abbreviate the list mapping coding and make the idea easier to follow Mar 12 reviewed Close Finding the equation of tangent lines where a function has a specified slope Mar 12 comment Generating Z^*_n Select[Range[21], NumericQ@MultiplicativeOrder[21, #] &] Mar 12 comment Generating Z^*_n Position[MultiplicativeOrder[21, #] & /@ Range@20, _?IntegerQ, 1] Mar 11 comment Calculating eigenvalues of a large matrix takes a long time Your matrix hasn't the form you are describing. Try m//MatrixForm Mar 11 revised Calculating eigenvalues of a large matrix takes a long time added 16 characters in body Mar 11 comment ParallelMap not using all of the available kernels Have you tried the same things with another (smaller) parallelizable load?