Skip to main content

internet - Problems with “Test Connectivity” and the Pacletserver


I know there has been a similar questions to this already but the solution did not work for me so here again:


I have internet connection and I can execute such commands like:


Import["http://www.google.com"]


I am also able to use the functionality of Wolfram Alpha such as


== GDP of the USA

but when I do


CountryData["France", "Population"]

it tells me that there is no connection and that I should test the connectivity which I did via "Edit->Preferences->Internet Connectivity->Test Connectivity". When I tried testing it it returned:


"PacletSiteUpdate::err: An error occurred attempting to update paclet information from site http://pacletserver.wolfram.com. Failed writing received data to disk/application"

When I tried to ping the pacletserver.wolfram.com directly in the cmd it tried to ping pacletserver2.wolfram.com which failed. When I did the same with pacletserver1.wolfram.com and pacletserver3.wolfram.com it worked just fine.



So I tried Nikita's Solution with the windows host file which did not work for me.


After that I tried to change the server address within Mathematica with


$PacletSite = pacletserver1.wolfram.com

After that the Connectivity Test returned success. The CountryData-function did still not work, though. When I re-started Mathematica the $PacletSite contains the original value (http://pacletserver.wolfram.com) and the Connectivity Test fails again.


Even though the CountryData-function did not work, I think that the problem is that Mathematica tries to connect to pacletserver2.wolfram.com and the $PacletSite-Value does not influence the CountryData-function.


So is there a way to change the way Mathematica tries to connect to the pacletserver and tell it only to connect to pacletserver1.wolfram.com or pacletserver3.wolfram.com?


Thank you very much for your help




Comments

Post a Comment

Popular posts from this blog

functions - Get leading series expansion term?

Given a function f[x] , I would like to have a function leadingSeries that returns just the leading term in the series around x=0 . For example: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x)] x and leadingSeries[(1/x + 2 + (1 - 1/x^3)/4)/(4 + x)] -(1/(16 x^3)) Is there such a function in Mathematica? Or maybe one can implement it efficiently? EDIT I finally went with the following implementation, based on Carl Woll 's answer: lds[ex_,x_]:=( (ex/.x->(x+O[x]^2))/.SeriesData[U_,Z_,L_List,Mi_,Ma_,De_]:>SeriesData[U,Z,{L[[1]]},Mi,Mi+1,De]//Quiet//Normal) The advantage is, that this one also properly works with functions whose leading term is a constant: lds[Exp[x],x] 1 Answer Update 1 Updated to eliminate SeriesData and to not return additional terms Perhaps you could use: leadingSeries[expr_, x_] := Normal[expr /. x->(x+O[x]^2) /. a_List :> Take[a, 1]] Then for your examples: leadingSeries[(1/x + 2)/(4 + 1/x^2 + x), x] leadingSeries[Exp[x], x] leadingSeries[(1/x + 2 + (1 - 1/x...
Post a Comment
Read more

mathematical optimization - Minimizing using indices, error: Part::pkspec1: The expression cannot be used as a part specification

I want to use Minimize where the variables to minimize are indices pointing into an array. Here a MWE that hopefully shows what my problem is. vars = u@# & /@ Range[3]; cons = Flatten@ { Table[(u[j] != #) & /@ vars[[j + 1 ;; -1]], {j, 1, 3 - 1}], 1 vec1 = {1, 2, 3}; vec2 = {1, 2, 3}; Minimize[{Total@((vec1[[#]] - vec2[[u[#]]])^2 & /@ Range[1, 3]), cons}, vars, Integers] The error I get: Part::pkspec1: The expression u[1] cannot be used as a part specification. >> Answer Ok, it seems that one can get around Mathematica trying to evaluate vec2[[u[1]]] too early by using the function Indexed[vec2,u[1]] . The working MWE would then look like the following: vars = u@# & /@ Range[3]; cons = Flatten@{ Table[(u[j] != #) & /@ vars[[j + 1 ;; -1]], {j, 1, 3 - 1}], 1 vec1 = {1, 2, 3}; vec2 = {1, 2, 3}; NMinimize[ {Total@((vec1[[#]] - Indexed[vec2, u[#]])^2 & /@ R...
Post a Comment
Read more

plotting - Plot 4D data with color as 4th dimension

I have a list of 4D data (x position, y position, amplitude, wavelength). I want to plot x, y, and amplitude on a 3D plot and have the color of the points correspond to the wavelength. I have seen many examples using functions to define color but my wavelength cannot be expressed by an analytic function. Is there a simple way to do this? Answer Here a another possible way to visualize 4D data: data = Flatten[Table[{x, y, x^2 + y^2, Sin[x - y]}, {x, -Pi, Pi,Pi/10}, {y,-Pi,Pi, Pi/10}], 1]; You can use the function Point along with VertexColors . Now the points are places using the first three elements and the color is determined by the fourth. In this case I used Hue, but you can use whatever you prefer. Graphics3D[ Point[data[[All, 1 ;; 3]], VertexColors -> Hue /@ data[[All, 4]]], Axes -> True, BoxRatios -> {1, 1, 1/GoldenRatio}]
Post a Comment
Read more