11
votes
1answer
218 views

Structure of Graphics (esp. those produced by Plot, ListPlot, etc.)

I'm looking for a description of the structure of Graphics objects, aimed at the advanced Mathematica programmer. The motivation for this question is the ...
5
votes
1answer
420 views

How to make a filled Ellipsoid?

I want to make a filled Ellipsoid, but it seems Filling options doesn't work in Graphics ...
8
votes
5answers
2k views

Sum all numbers from 1 to 1000 divided by either 2,3,5 or 7

How do I find the sum all numbers from 1 to 1000 divided by atleast one of 2,3,5 or 7? EDIT: I am sorry for complicating this, but I need it to work for 10^11. So anything that requires too much heap ...
3
votes
2answers
292 views

How to declare a function that uses local variables of a module outside this module?

I have the following code Module[{f,x=0}, f[t_] := x + t; ..........; ...f[1]...; ..........; ] My aim is to put the declaration of the function ...
0
votes
1answer
228 views

String to File removing quotation marks

If I print a string to a file it also adds quotation marks to the string. Here is an example: a = "test \t test" a >> file FilePrint["file"] How can I ...
8
votes
1answer
654 views

Integral of the Sinc product

Let as consider the following integral $$ B_n = \int_0^\infty \prod_{k=1,3,5,\dots}^n\frac{\sin (x/k)}{x/k}dx $$ By definition, Sinc[x]=Sin[x]/x therefore ...
12
votes
2answers
9k views

Plotting the frequency spectrum of a data series using Fourier

testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full] Gives me Which I do not expect because the Fourier ...
4
votes
1answer
468 views

Implementation of the Polynomial Chinese Remainder Theorem

I would like an implementation of the Chinese Remainder Theorem for polynomials in $\mathbb{Z}[x]$, that is, a function ...
3
votes
1answer
439 views

Problem in units convertion when multipliying Boltzmann constant and a temperature

When define the temperature of a variable in Celsius, Mathematica 9.0 does not calculate the right answer when multiplying by boltzmann constant. Example: ...
12
votes
5answers
723 views

What's the cleanest functional-programming style way to perform this list operation?

I am looking for the correct method for accomplishing the unknown piece in the following code snippet: rolls = Tuples[Range[1, 4], {2}] ...
7
votes
3answers
1k views

Programming Mathematica in plaintext, i.e. no formatting, non-notebook

I'm new to Mathematica and I've just begun reading Paul Wellin's Programming in Mathematica. The book, like many other books and online tutorials, revolves around using the notebook, with all its ...
0
votes
1answer
148 views

Getting output in the same way as most Stat packages

I have been looking at several of the timeseries functions in mathematica, however running a process like ARDL, ARMA, GARCH or ARCH you would be able to get a ANOVA table, with its coefficients and p ...
2
votes
1answer
579 views

ContourPlot shows only part of the contours [duplicate]

Consider these contour plots: f[x_,y_]:=Cos[x] + Cos[y] ContourPlot[f[x, y] == 0, {x, 0, 4 Pi}, {y, 0, 4 Pi}] ...
42
votes
3answers
2k views

Applying TextRecognize on alpha-numerical table

From time to time I have to extract data from scanned papers or rasterized PDFs. Imagine a table of the following kind (but much longer): A naive application of ...
0
votes
1answer
61 views

can someone how to plot $x = c$ in a different color scheme? [duplicate]

Exactly as title says. I do not know why I am having so much trouble with this. I have googled many solutions and I cannot find a straightforward answer. Also, the only method I know is "Gridlines" ...
3
votes
1answer
233 views

DistributionFitTest with WeightedData?

My problem is related to statistical testing with weighted data. I have a data sample and I assume that a part of the data follows a specific distribution (Pareto). So I fit my data to a distribution ...
3
votes
2answers
357 views

Long text inside a grid does not word wrap

If I create a simple grid with Ctrl+, and paste a long piece of text outside the boxes (I'm sure you can find some yourself), then that text does not break at the width of the window in Mathematica. ...
1
vote
3answers
210 views

Plotting data with 4 columns!

I'd like 3Dplot a list of data with 4 columns (these are mesh outputs): x1 y1 z1 Dose1 x2 y2 z2 Dose2 . . . which command i ...
2
votes
0answers
664 views

Solving a diffusion equation

I need to solve a particular diffusion equation with NO boundaries http://astronomy.nju.edu.cn/~chenpf/c/courses/fluid/pringle81.pdf equation (2.10) with nu = cost. ...
3
votes
0answers
69 views

Combine 2D images perpendicular to each other [duplicate]

I would like to create a slice plot from multiple density plots in Mathematica. A solution for this probem has been posted in this forum before (Is there something like DensityPlot3D?). But how would ...
2
votes
2answers
287 views

Applying rules with functions to expressions with derivatives

I have a function that I want to see applied, potentially within a derivative. The use of delayed vs. non-delayed rules seems irrelevant. See the following: ...
0
votes
2answers
528 views

Finding max value of each column of 4x4 Array

I have the following array in both MatrixForm and List form ...
4
votes
2answers
372 views

Quickly reducing the number of decimal digits for a set of real numbers

How can I quickly convert a number with $n$ decimal points to a number of with $m$ decimal points? Round works, however, it is slower than I would like. This ...
1
vote
1answer
91 views

Matrix generation

I have a $2x2$ matrix $M$. $M$ has the following form: M = {{a, bExp[-2ikz]}, {bExp[2ikz], a}} $a, b, k - const.$ z is ...
2
votes
1answer
129 views

How to define a function of z[bar], etc

Using Displaying index as subscript on output: e.g. C[i] -> C_i with Notation[...] or Interpretation[..]? I have often ended up wanting to define functions of annotated variables to better match my ...
1
vote
2answers
201 views

Taking a percentage of data from a list or a table

I have a list of data and for the calculation I only need the a of portion of the data. I know that Take[data, {1,100}], for example, is taking line 1 to 100 of the ...
5
votes
0answers
362 views

NDSolve and memory usage

After some googling, i've found similar problems around, but didn't find a 100% satisfactory answer, so let me ask here: I'd like to solve a 1+1 problem using the method of lines. In spherical ...
5
votes
1answer
190 views

Verify Harmonic Addition Theorem with Mathematica

I've calculated the harmonic addition theorem and would just like to check my result with Mathematica. However, ...
5
votes
1answer
544 views

Labelling of multiple BarChart elements with “Stacked” layout

I am trying to create a stacked BarChart where each BarChart has different ChartLabels. ...
3
votes
3answers
247 views

Logical AND operation over several comparisons

Let x and y be arrays defined as Array[x, m], Array[y,n] respectively. How to generate the following function of $x$ and $y$ for variable $k$: ...
10
votes
1answer
778 views

Roads network visualization by thickness and color intensity by population from GIS files

We can have road networks of the countries in GIS shape file.For exmple from here. Normally traffic flows are proportionate to populations of the cities. I wonder how we can have the same in ...
2
votes
1answer
158 views

Remove braces, {}, from around DynamicModule output?

Is there a way to remove the braces from the front end output associated with DynamicModule? For instance: ...
2
votes
3answers
319 views

How to manipulate log arguments?

A common problem I have with Mathematica is needing to manipulate the arguments of logarithms. Typically, I need to take ratios of the log arguments Mathematica gives me by default. That's to say ...
4
votes
3answers
403 views

Plotting the direction field of a differential equation

I have to sketch the direction field for the following differential equation: $$\frac{dy}{dx}=\frac{-0.02 y +0.00002 xy}{0.08 x-0.001xy}$$ This is the code I used, which gives an incorrect plot: ...
2
votes
1answer
145 views

Integral of GeneratingFunction

I know that GeneratingFunction can be used to compute the generating function $\sum_{n=0}^\infty a_n x^n$ of a sequence $(a_n)_n$ via GeneratingFunction[a[n],n,x] ...
1
vote
1answer
359 views

Simplify vector expression - is there something like “Factor” for vectors, dot products etc.?

I am looking for a way to simplify dot products etc. Here is a minimal example: Lets say I have two vectors a and b: Array[a,2] Array[b,2] Now I evaluate their ...
2
votes
2answers
174 views

How to unprotect GeneratingFunction

I'm trying to add custom downvalues for GeneratingFunction, and to do so I thought I just had to Unprotect it. However, that ...
7
votes
5answers
198 views

Selecting terms from a matrix

There are similar questions to this on the forum but none fit the purpose here: I would like to extract certain elements of a matrix depending on whether a factor is present or not, and create ...
1
vote
0answers
58 views

Rounding to the nearest decimal [duplicate]

If I have a bunch of numbers in a list {1.435243523432,2434.2321321412,5.8239897,...}, without multiplying everything by some power of ten and then dividing by that ...
5
votes
1answer
203 views

Make dynamic controls from existing list

I have a list of variables (c1,c2,c3,c4), each with its ...
11
votes
2answers
658 views

Dynamic Programming with delayed evaluation

By using dynamical programming, we can save intermediate steps for recursive relations, as in f[n_]:= f[n] = f[n-1] + f[n-2] However, this only stores ...
3
votes
1answer
260 views

Minimizing a potential using Solve

I am having problems minimizing a potential: $\text{V}(h,\eta)=\gamma \left(-h^2\right) \left(\eta ^2 \cos ^2(\theta )+\eta \cos (\delta ) \sqrt{-\eta ^2-h^2+1} \sin (2 \theta )+\left(-\eta ...
2
votes
1answer
230 views

Can't create a simple CDF

I decided it was time I investigated CDFs, so I created the following simple Manipulate using Mathematica version 9.0.1.0: ...
0
votes
0answers
76 views

When to use memoization concept in Mathematica? [duplicate]

I have recently learnt memoization concept. But I am not sure in what scenarios i need to use this concept. if someone can help me out with different scenarios it would help me a lot to develop a ...
7
votes
2answers
5k views

Does Mathematica implement the fast Fourier transform?

Is there a fast Fourier transform in Mathematica? Although looking in the help I could not find one. I am looking to implement the equivalent of fft in MATLAB.
1
vote
2answers
770 views

How to input a 3-vector in spherical coordinates?

I would like to input a 3-vectors in spherical coordinates $(r, \theta, \phi)$ and be able to operate on such vectors (dot and cross product) with the results being given in the same spherical ...
1
vote
1answer
102 views

Is there a TwoColoring function of Graph object?

The following code shows the GraphUtilities package makes a problem for Graph object. I want to use a ...
0
votes
2answers
115 views

Error in the result

I want solve the following equation: $ x''(t) + 9 x(t) = Cos(3t) ,\; t \in [0,10] $ $ x(0)= x'(0) =1$ I have to use the Explicit Euler method and a partition of the interval in $N+1$ ...

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