All Questions

0
votes
0answers
44 views

How should I provide Dataset slot names in function definitions? [on hold]

Say I have a Dataset like the following: ...
1
vote
0answers
37 views

ColorFunction - custom colors and scaling

I am trying to implement my own colors and scaling into the ColorFunction which I use in ListDensityPlot. I have several lists of 2D values which I plot in multiple images and I want to scale the data ...
1
vote
0answers
46 views

Optimization in MMA for time resolved spectroscopy

I want to fit some spectroscopic data with a model. I detect the fluorescence of something over different wavelengths. The detection over each wavelength is one data set in time. The lifetimes of ...
0
votes
0answers
41 views

How to display a list using numerical values? [duplicate]

Suppose I compute the eigenvectors of a matrix like this Eigenvectors [{{3, 2, 3, 1}, {2, 3, 1, 1}, {0, 0, 2, 1}, {2, 3, 2, 1}}] The result I get looks like: ...
0
votes
0answers
34 views

how do I multiply two arrays in Javascript? [on hold]

I want to multiply two arrays, as in element per element: [1,2,3,4,5] * [2,3,4,5,6] = [2,6,12,25,30] I am new to JS and just have no clue... Thanks, Pam
1
vote
1answer
39 views

Multiway Systems Rules List Management

I'm working with a multiway system and I have a number of different mutation rule lists. I need an efficient way of managing which rule lists I apply. Here is the basic multiway system code that I'm ...
0
votes
0answers
23 views

ErrorListPlot Not Plotting

I'm on Mathematica 6.0, it's the copy my school gave me for a lab course. ErrorListPlot produces a graph, but there is nothing on it. I have checked the table constructed using ErrorBar and it's good. ...
3
votes
3answers
115 views

How to do algebra on unsolved integrals?

I am working with functions calculated from a set of general basis functions. ...
1
vote
1answer
39 views

How to append data in an already existing data .txt file in newline or in tab separtion?

Say I have an already existing .txt file containing data in the following format. $a \qquad b$ Now at different times I will successively have data like ...
0
votes
1answer
34 views

Understanding `TransformedDistribution` behavior on two similar lines of code

The two following lines of code does not give the same output. Mathematica manages to calculate the first one but fails to calculate the second one. ...
1
vote
0answers
39 views

How to get grid items with a gradient background to behave well?

I have a table that looks something like this ...
3
votes
2answers
106 views

Compute the average distance from the base of a rectangular pyramid to its apex

How can I compute the average distance from the base of a rectangular pyramid to its apex? For example, if the base of the pyramid is 30 feet by 8 feet, and the height of the pyramid is 12 feet, then ...
0
votes
0answers
48 views

Usage of @ symbol in Mathematica [duplicate]

What is the purpose of @ symbol? Also, I would appreciate if somebody could provide a webpage where such functional special symbols are documented
1
vote
2answers
119 views

Symbolic combinations

If I have 3 lists: {a,a},{b,b},{c,c}, then the desired output is ...
9
votes
2answers
372 views

Phase portrait on a cylinder

It is very nice and very easy to make a sketch of a phase portrait with StreamPlot. For example, for the classical pendulum, defined by $$ \dot x=y,\\ \dot y=-\sin x, $$ The code ...
2
votes
1answer
217 views

Quick way to tell if matrix is integer-only?

What's the most shortest one-liner code to tell whether a matrix is integer-only? I've come up with: Length@Cases[A // Flatten, _?(Not@*IntegerQ)] == 0 but ...
2
votes
2answers
50 views

Include more padding between tick marks and plot [duplicate]

How can I modify the code below to add some padding between my tick marks and 3D plot? It is not a problem in this example, but often my tick marks collide with my axes. ...
3
votes
1answer
49 views

Clustering image data by intensity and position

I'd like to apply FindClusters or ClusteringComponents to image data of an indistinct edge, with the goal of segmenting the ...
2
votes
0answers
46 views

Temporary variable not removed in Mathematica 10

In Mathematica 10, the documentation still states that a symbol with attribute Temporary will automatically be removed when it is no longer needed. Now consider ...
1
vote
2answers
34 views

Exporting mixed data of matrices and vectors / lists

thank you for reading my question. I have a problem trying to export mixed data from Mathematica. I have different matrices and vectors, which should be combined to a output file. Here a ...
4
votes
0answers
44 views

How to get data from DB into dataset with keys

I'm a Mathematica newbie and I have the following problem: I connect to a Oracle DB and read out a set of variables, further on I want to histogram some of the variables. A Dataset seems to be the ...
4
votes
3answers
89 views

How to separate factors by dependent variables (arguments)?

How can I separate factors in an expression by their dependent variables? For example: expr = b * c[2] * a[x] * 2 * x^2 * g[x,y] * z[r] * D[q[x], {x, 4}]; I ...
5
votes
0answers
50 views

PenaltyFunction Option in NMinimize

I am curious if anybody has some experience in using the built-in Option "PenaltyFunction" in any of the numerical optimization functions like NMinimize. According to the documentation the user ...
0
votes
3answers
59 views

High-Precision NSolve

I need to calculate the intersection of two curves f1[x_] := ((Zl ρ ) Exp[-x]) f2[x_] := (α k e^2 /x^2) Where ...
0
votes
1answer
15 views

Numeric-type attributes for symbols (analog of NumericFunction)

Is there an attribute for symbols that makes NumericQ give True? For example Pi and ...
1
vote
3answers
83 views

How to extract arguments of functions in an expression?

How can I extract the argument of a function in an expression? expr=b[c]; I need some f[expr] that will return c. d[f[expr]] -> d[c]
0
votes
1answer
129 views

Plotting Integral equation

I want to plot the following indefinite integral : $C_l^{CC}=\int k^2\mathrm{d}k\: [e^{-2k^{2}}P_{Cl}^2(k\eta)|\dot{h}(\eta)|^2]$ with k from 0 to some large value (considered to be $\infty$), ...
0
votes
0answers
9 views

Difference Equation System constructed with SetDelayed: How I can set Non-exploding break?

I have a Difference Equation System constructed with SetDelayed. The system is like as follow. ...
0
votes
2answers
38 views

How to use Expected values in symbolic solving

How can I create a function that brackets off terms of an expectation value? For example, I have : f = a[x] + c1*b[x] + c2*c[x]; g = Expand[f*f]; ...
1
vote
1answer
101 views

Making a list of rules form the list of elements

Starting from the list: {f[q1, q2], f[q3, q4], g[q1], g[q2, q3, q4], d[k1 - q1], d[k2 - q2 - q3 -q4]} I would like to get the result: ...
4
votes
1answer
92 views

Problem on limit involving complex numbers

I have $${\frac{(6 k+1)^{k}}{(2 k+5)^{k}}}*(z-2 i)^k$$ and I need to find it's limit for $k$ approaching infinity. ...
4
votes
1answer
35 views

what's the meaning of “-mathlink” as part of Arg for LinkLaunch?

LinkLaunch["MathKernel -mathlink"] LinkLaunch["MathKernel"] The both code line above can launch a MathKernel. What's the difference of them? what's the meaning of ...
2
votes
1answer
65 views

Scale coloring of ContourPlot

The answer given here solved how to use the same color scale across multiple plots within the function ListContourPlot. I can't for the life of me map this solution onto the function ContourPlot that ...
0
votes
1answer
47 views

Display trailing zeros in ticks

When I specify tick marks in ArrayPlot I want to keep the number of trailing zero's that I specify. One work around is to use a label for that tick mark (i.e. Ticks->{0.8,0.9,{1.0,"1.0"},1.1,1.2}), ...
2
votes
1answer
34 views

ChartLegends only displays the last two legends in the list

I would like to add 4 legends on a simple bar chart below, but only the last 2 legends appear on the graph. ...
0
votes
0answers
25 views

How to set the step in NMinimize

I want to fit multiple data sets with 104 variables. I use NMinimize to do that. I minimize the difference between data and my objective function. How can I tell ...
4
votes
1answer
63 views

RegionPlot with PlotRange vs RegionPlot with domain

Consider you want to plot R = ImplicitRegion[x > 0 && y == -((5 x)/3), {x, y}]; In ContourPlot of an ImplicitRegion defined by the intersecton of ...
1
vote
1answer
64 views

Plotting a function in {X(Y),Y} space

The code below generates some data and defines a function f[x,cb]:=NMaximize[expr,x] that upon being evaluated returns: {function value at max $x$,the function maximizing $x$}. ...
2
votes
5answers
165 views

Is there a way to use Table[] without having to calculate my function twice?

I'm trying to use Table[] more to be more in the spirit of Mathematica. So for example, I might replace this piece of code: ...
3
votes
1answer
64 views

Raster to Image conversion problem

There are 3 ways to convert a Raster into an Image : only 1 works for me with version 10.0.1, and 2 work with version 9 (same computer, OS X 10.9.5) Has anyone the same problem or is it localized to ...
2
votes
1answer
99 views

Neighbourhood - Calculations

SeedRandom[0]; n = 5; (m = N @ RandomInteger[{1, 3}, {n, n}]) // MatrixForm result1 = MeanFilter[m, 1] // MatrixForm ...
2
votes
0answers
27 views

Max iterations in K-means clustering algorithm

I want to use k-means for clustering. I have used the ClusteringComponents function but I said how can I control the max-iteration for k-means ?
2
votes
3answers
57 views

Tangled up in sequences and recurrence relations

I took a trip through sequences and recurrence relations and I got tangled up since the documentation didn't help much. I'm sure you can. Given a sequence ...
0
votes
1answer
74 views

Use separate options for different elements in Show

I have a few plots of different type. plot1 has gridlines and the rest do not. I use the option Method -> {"GridLinesInFront" -> True}] when plotting plot1. When I use Show to combine the plots the ...
2
votes
2answers
47 views

Set the same color scale across multiple ListContourPlots?

This is probably straightforward - but how would I set the same color scale across multiple ListContourPlots? if I have values from 10 to 25 on one ListContourPlot and values from 40 to 100 on ...
3
votes
1answer
60 views

NIntegrate on tetrahedron

I've been trying to numerically calculate an integral in a tetrahedron of a discretized domain. In some cases when I specify a method I've been getting the error message NIntegrate::femonly ...
0
votes
0answers
14 views

what's the difference between CreateKernelLink() and CreateKernelLink(String Arg)?

I have a .NET program which will connect to MathKernel. When the program runs, there will be a icon of MathKernel on the taskbar. ...
6
votes
2answers
174 views

How to redefine the type of multiplication in Det

I would like to redefine the type of multiplication that is used in Det (calculates the determinant). Instead of the standard multiplication I would like to use a custom function Fun[a,b] (which takes ...
0
votes
1answer
23 views

Problem with DSolve [on hold]

I am trying to use DSolve: DSolve[{y'[x] == x/y, y'[8] == 2}, y[x], x] But I get an error message: DSolve::dvnoarg: The ...

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