Mathematica

Mathematica

  • All Sites
  • All Meta Sites

0 answers

What is the Fourier series of $e^{\mu\cos\theta}$?

Motivation: I want to solve this convolution problem on the circle: find $f$, given $g$ and $$ g(\theta) = \int_{S^1} e^{\mu\cos(\theta-\phi)}g(\phi)\ d\phi. $$ To do this, I want to find the Fourier …

1 answer

What are the labels for minor ticks in a log scale graph?

What are the labels for the minor ticks in a log scale graph? I would like to label them. So, I want to know how to calculate the value for each of the minor tick.

3 answers

Plotting a region in $3D$ space

I would like to know if someone knows of a software where I can plot the following region $$ D = \{ (x,y,z) \in \mathbb{R}^3: 0 \leq x \leq 1 , \; x^2 \leq y \leq x, \; \; 0 \leq z \leq x \} $$ ...

2 answers

How do I URL-escape a string in Mathematica?

For example, urlesc["foo.cgi?abc=123"] should return foo.cgi%3Fabc%3D123 This is also known as percent-encoding. Also, for better readability, spaces should encode to pluses. I believe that's …

1 answer

Why is this Mathematica function definition returning an error?

I am trying to put in a rather large function into mathematica: (http://i.imgur.com/BqBYxfp.png) I want to get it in so I can compute the global maxima, but I keep getting an error when I try and …

0 answers

Convert Lat/Long to X/Y for Albers Projection on US Map Image

I'm trying to use C# or Javascript to convert Lat/Longs into X/Y Coordinates to position divs with CSS (left, top) onto a background image of a US map. The standard map projection of the United ...

3 answers

Redirecting Output from Mathematica Script to PIPE Instead of stdout Using subprocess.Popen Yields Null String

I have a Mathematica script that I can run as a bash executable from Terminal. I want to run it from within Python and get the result out. This is the code I wanted to use: proc = ...

2 answers

How to improve the performance of this piece of code?

I'm trying to learn a bit of Julia, after reading the manual for several hours, I wrote the following piece of code: ie = 200; ez = zeros(ie + 1); hy = zeros(ie); fdtd1d (steps)= for n in ...

0 answers

How to import a excel file which contains more than 100,000 rows in Mathematica

I have a Microsoft Excel file which contains 110,000 rows of data. When I import the file using the command Import in Mathematica, I found out that it can only import about 60,000 rows and hence lots …

1 answer

How to set the step of plotting by one of axes in Wolfram Mathematica

I have a data such as list of points x,y,z. I added interpolation by splines as f = Interpolation[{#[[1 ;; 2]], #[[3]]} & /@ data, Method -> "Spline"] And after all I try to plot ...

0 answers

How can I plot error bars in Mathematica on a bar graph?

I'm working with Mathematica and I'm trying to plot a bar graph. I can plot just the bar graph, but I can't get the error bars to work. The only one I can manage to get to work is using ...

2 answers

mathematica physical constants without units

It is helpful to use physical constants included in mathematica. Unfortunately they all include units. This provides errors when trying to integrate numerically. Is there a way just to get the value …

0 answers

Sound Recording not working

I have a Dell Inspiron 1525 running Windows Vista. I intend to record a sound input on my PC using Mathematica 9. It's fairly simple with the command: SystemDialogInput["RecordSound"] Afterwards I …

1 answer

Mathematica help ~ converting elements in a matrix to string

I have this 10x10 matrix (or Array) in Mathematica whose elements which have the value -1 or +1. I want to change all the -1 to a string " " (here its just the spacebar) and all the +1's to the symbol …

Apr 19 at 7:42
4 answers

How to create a function directly from the output of Solve

If I evaluate Solve[f[x,y]==0,x], I get a bunch of solutions like: {{x -> something g[y]}, {x -> something else}}, etc. Now I want to convert each of those x->somethings into a function. …

Apr 18 at 1:09
1 answer

How to set the default image resolution for exporting?

I know Export["image.png", image, ImageResolution -> 300]. But it there a way to set the default value for ImageResolution?

Apr 17 at 21:06
0 answers

Uzawa Algorithm with mixed constraints

I have difficulty resolving an exercise about Uzawa algorithm (with basic requirements: J is a quadratic function and a symmetric matrix A) gi =−1+ max(0, 0.625−10(ti −0.4)^2) with ti=ih Then we …

0 answers

Roots and Weights

I use a Mathematica package to compute roots and weights (and other things) but the package gives me only the expression of the roots in $\omega$-basis (basis of fundamental weights) and in the ...

3 answers

Create a graph using Mathematica and Python

I was wondering how I would go about using Python to create a Graph with Mathematica. I want to be able to use python code to invoke mathematica to create a new graph, using data from a CSV file.

Apr 16 at 13:00
1 answer

Why is a big loop within a small loop faster than a small loop within a big one?

This is my Perl code $big=10_000_000; #A:big loop outside my $begin_time = time; foreach my $i (1..$big) { foreach my $p (1..10){ } } my $end_time = time; my ...

Apr 16 at 12:29
1 answer

Wrong result of a recursive relation

I took this code from here on page 15. The code: s[i_] := s[i] = 2*s[i - 1] - 3*(s[i - 1])^2 s[0] = SetAccuracy[3/10, 20] Do[Print[s[i]], {i, 0, 40, 10}] Output: 3/10 0.33333333333333 0.3333333 …

Apr 16 at 12:16
0 answers

a width of interval on each step of iteration

Tell me please , is in Mathematica a standard function which can find a width of interval? I have to find it for each iteration. (*Newton's method*) step[f_, iter_, inter_] := Module[{x = …

3 answers

How do I export a higher resolution image of a Mathematica Graph object?

How do I export a re-sized version of the output I get from a call to GraphPlot (or TreePlot if they produce different output) to a jpg file? Currently, I'm simply calling Export[file_name, G] where …

Apr 15 at 14:32
3 answers

Find min of $\frac{\left( \sum kx_k \right) \left( \sum x^2_k \right)}{\left( \sum x_k \right)^3}$

With $n \ge 2$ and $x_1,\ x_2,\ \dots,\ x_n > 0$. Find the minimum of: $$ M = \frac{(x_1 + 2 x_2 + ...+ nx_n)( x^2_1 + x^2_2 +...+x^2_n)} {\left( x_1 + x_2 +...+ x_n \right)^3}$$ For specific …

0 answers

the Newton's method in the mean of Interval

I have to write the Newton's method in the point which is the mean of Interval. and in 'While' loop it could be while the function(point)>eps. point = Mean[inter]; step[f_,inter_] := ...

1 answer

How does the base of a group determine the “sort” of the elements in the group

I'm trying to study groups in Mathematica, and I've asked a question on Mathematica.SE that perhaps only someone from Math.SE could answer. Related: How does GroupActionBase affect the order of ...

0 answers

Finding normal, tangent, and binomial of a Bezier function in Mathematica

I'm currently trying to find the normal, tangent, and binomial across an iso-surface. Here is the code I have to find them: graphT[curve_, t_] := ( varbez = BezierFunction[curve]; temp = varbez'; …

Apr 14 at 23:28
0 answers

procedure with iterations of the first step Newton's method IN POINT

I have to write the procedure with iterations of the first step Newton's method in Moore's form in Mathematica8, exactly on this example: GIVEN: f[x_]:=x*x-8*x+7; inter={5, 9}; eps = 10^(-6); TO ...

3 answers

mathematica FullSimplify cowardly refusing fully evaluate real parts of a complex number?

I'm wondering if there is a different command than FullSimplify to tell mathematica to do the computation requested. Here's three variations of a simplification attempt FullSimplify[Re[ …

Apr 14 at 14:43
1 answer

Mathematica quits calculation automatically

I have this little program that is adopted from a Wolfram demonstrations project (link here: http://demonstrations.wolfram.com/PercolationOnASquareGrid/). I want to see what happen if I increase the …

Apr 12 at 18:51
15 30 50 per page
1 2 3