3
votes
2answers
218 views

Showing a forest with root of the trees on the top

I have a Graph object that contains a forest with directed trees. I want to draw the forest such that the root of the trees are on the top and the leaves are on the bottom. If I use the following line ...
3
votes
3answers
2k views

Map w/ multiple arguments [duplicate]

Possible Duplicate: How do I use Map for a function with two arguments? If I have a function: F[x_,y_,z_]:=x*y*z and I want to call it with several ...
2
votes
1answer
216 views

Model fitting to noisy data with a custom minimization function

I'm looking into fitting some data with Mathematica. I've got my head around how NonlinearModelFit works (I've been using the Levenberg-Marquardt algorithm for some ...
2
votes
2answers
243 views

Tweaking Solve for systems of polynomial equations

I am trying to solve the following system of $6$ quadratic equations in $6$ variables: ...
2
votes
1answer
141 views

How can I exhibit the evaluation of formulas in a Mathcad-like way?

How can I create a function F that works like this: x = 2 f1 = x^2 + 3 f2=x+5 F[f1] x^2 + 3 = 2^2 + 3 = 7 ...
2
votes
2answers
270 views

How can I build a GraphicsGrid of arbitrary size?

This is actually a very simple scenario, in order to make simpler this question Part I. Consider the following piece of Mathematica code ...
2
votes
1answer
253 views

Mesh inside Plot legend

I have a plot for which I would like to create an legend that is black and white printer friendly. I have seen Jen's legendmaker but I don't know how to adapt it. I need help in making the legend for ...
2
votes
1answer
224 views

Including two ListLinePlots in a 3D graphic

I have two lists of data which I am plotting on two ListLinePlots. I would like to have these two plots appear perpendicular to each other on a 3D graphic. I have ...
2
votes
0answers
544 views

ParametricNDSolveValue or NDSolve + fitting

I have been trying to find the value for the parameter kestim that yields the best fit of a model to some data points. datac has ...
2
votes
2answers
484 views

Dynamically choosing which Manipulate controls to use

I have some stuff I would like to manipulate, using two different kinds of control, one at a time, using another variable as a switch. These controls are similar in principle to ...
2
votes
1answer
728 views

Export Animate command to MOV video

I'm trying to export a rather complex Animate command into a full-HD resolution video, but having no success so far. The animation has around 520 frames (the number ...
2
votes
2answers
422 views

MathLink and CDF

So far I have read that some things are not supported in CDFs. Istvan-zachar mentioned very useful things in his post. Unfortunately he mentioned that MathLink operations, including J/Link and ...
2
votes
1answer
152 views

How to set PageWidth when using PutAppend to append expressions to a file?

Do[ PutAppend[Table[i, {RandomInteger[100]}], "./file.m"], {i, 100} ] I'd like each inner list to always appear on the same line, but not automatically ...
1
vote
2answers
62 views

Unintentional function memoisation via Dynamic

I needed to display edge labels of a graph in a way that allows the edge labels to be moved. ...
1
vote
2answers
481 views

Research positions of lists of varying size

I'm new to the site and I am French, so I ask your indulgence for my future mistakes in English. I would like to optimise the following code : ...
1
vote
3answers
404 views

Generate random points in a region with higher probability in a sub-region

I am trying to generate random samples of points in the unit square in such a way that points inside a given circle are twice as likely to be selected as points outside that circle. I tried to ...
1
vote
2answers
334 views

EdgeRenderingFunction question

(Edit 1 : I added this paragraph after the original post, for context) Some context for this question can be found in another post (Problem with EdgeRenderingFunction), which however may be taken ...
1
vote
2answers
503 views

How can I get even steps on x and y axes in a plot?

I'm plotting the shortest distance from a point to a line using the following code ...
1
vote
2answers
924 views

Can I improve the importing speed of Excel data?

I have data in an Excel spreadsheet that has 4 rows and 1,000 columns. I am using Import as follows: ...
1
vote
1answer
162 views

How can I create some shorthand notation for a custom control?

Per this question, I have created a custom graphical control object which evaluates to a list of values. I would like to be able to create such an object quickly, rather than typing some command, ...
1
vote
3answers
1k views

How do I plot x[t] vs. x'[t] (where x[t] and x'[t] are solutions to NDSolve)?

I have a differential equation which I solved using NDSolve. I can easily plot x[t] vs. t, x'[t] vs. t, but.... how do I plot x[t] vs. x'[t]? I tried using the Evaluate function to simplify things, ...
1
vote
4answers
3k views

Creating a data1 versus data2 plot?

I have a table of data with multiple rows and columns, and I have to make a versus data table using two of these columns. Essentially, I have to set one column of data (column 3) as the y-axis and ...
0
votes
1answer
178 views

How can I build a GraphicsGrid of fixed size that rearranges the empty plots?

OK, let's make one final attempt; they say the third time is the lucky one! Following @rm-rf 's suggestions, I will try to be as clear as I can. My Mathematica code reads and plots simultaneously ...
0
votes
0answers
194 views

Is it possible to create an event handler for changes in values of variables?

I am creating a networking application in Mathematica that runs a non-stop simulation, and periodically receives new information from the remote server that affects the simulation. Whenever values ...
0
votes
1answer
547 views

Adding precision for the calculation of a function

I have some function $f(x)$ I wish to evaluate, which is yielding divide-by-zero errors for sufficiently large inputs. How do I increase the precision with which this function is evaluated in order ...
0
votes
1answer
242 views

How do I numerically solve a custom function?

Whenever I use functions like FindRoot or NDSolve, it sends x through the function and deals ...
-5
votes
1answer
2k views

Determine the 2D-Fourier transform of an Image

I am new to Mathematica and using Version 8.0. I want to calculate the 2D-Fourier Transform of a digital image and see its Magnitude and Phase Spectrum, and reconstruct it.
20
votes
1answer
437 views

Unintended edge extensions in 3D Cube rendering

I have arranged a certain configuration of cubes in 3D using the following code: ...
19
votes
1answer
448 views

What is wrong with triangle PlotMarkers in v.10.0.0?

In Mathematica 10.0.0 we have built-in graphical triangle PlotMarkers. Let us look closer on them: ...
19
votes
7answers
2k views

How do you draw the plane on which two vectors lie?

Given two arbitrary vectors $\textbf{v}_1$ and $\textbf{v}_2$, how can I draw the plane which they span?
17
votes
9answers
925 views

How to replace an element in a list based on the value of the next element?

I use Mathematica a little bit. I try to understand it, but it is hard I have a list of 5 numbers selected randomly from 0 and -1. I have to replace a 0 with a 1 when the 0 is followed by -1. My ...
17
votes
4answers
520 views

How do I introduce a new variable in a trigonometric equation?

I have the trigonometric equation \begin{equation*} \sin^8 x + 2\cos^8 x -\dfrac{1}{2}\cos^2 2x + 4\sin^2 x= 0. \end{equation*} By putting $t = \cos 2x$, I have \begin{equation*} \dfrac{3}{16} t^4+ ...
17
votes
1answer
477 views

When exporting an (animated) GIF, is it possible to specify the size of the color palette?

I've exported an animation to animated GIF, which generated a 15mb file. I've been asked if I could regenerate the file, limiting it to only 16 colors, but I can't find any documentation on how I ...
16
votes
1answer
1k views

How often does Mathematica contact its license server?

I know that Mathematica checks the validity of its license every time the program is launched. Say, however, that I have a valid license (which I do) and that I am running some code which takes a ...
16
votes
4answers
1k views

Random data generator

Inspired by Quality of random numbers I would like to set up a true random data generator in Mathematica. My idea is to use the static from an open microphone. I recall reading about extracting the ...
16
votes
4answers
729 views

How can I randomly generate a unique, unused symbol?

In a previous question on collecting terms for a multivariable polynomial, I answered with a solution that required a unused symbol to be used for a temporary substitution and back substitution. It ...
15
votes
3answers
959 views

Effective matrix power like algorithm

First example Suppose you want to calculate the 6th power of some matrix $A$. The brute force attempt of doing this is considering $$(((AA)A)A)A)A$$ which requires a total of 5 matrix ...
15
votes
3answers
386 views

How can I set Grid alignments using numbers?

There is an example in the Alignment documentation (it also appears in the Grid documentation): ...
14
votes
4answers
465 views

HoldForm doesn't hold form

In Mathematica version 10, HoldForm no longer produces the same results as in version 8 (edit: I only have versions 10 and 8 installed, so can't compare to version ...
14
votes
4answers
660 views

Measure perimeter of black edge in Mathematica

I have a pattern like the one below. How could I measure the total length of the perimeter of the black/white edge? This would give me a measure of spatial frequency. Any tips would be great! Thanks! ...
14
votes
1answer
1k views

Version 9 Blue Screen or Self-Test Error on Windows 7 64-bit

Update There is now an official response from Wolfram Support on this issue. Having recently installed Mathematica version 9 64-bit on Windows 7, I keep running into Self-Test Errors evaluating ...
14
votes
3answers
439 views

Grabbing a number of characters around a string pattern

If I have some string data: text = StringTake[ExampleData[{"Text", "DeclarationOfIndependence"}], 400] "When in the Course of human events, it becomes ...
14
votes
1answer
2k views

Parallelizing Numerical Integration in Mathematica

I have an ugly, six dimensional function that I need to integrate numerically. It works, but it currently take twelve hours to complete the calculation. Is there any good way to parallelize the ...
13
votes
2answers
220 views

Export Plots to PNG in Printout Style

When creating a plot in Mathematica 10 (OS X 10.9.4 and Win 7) the FrameLabel and Ticks are greyish and only the Frame itself is black (see Screenshot bellow). Only when exporting the plot to PDF all ...
13
votes
2answers
200 views

PlotLegends -> “Expressions” not working when Plot given one function

I don't get a legend when I use the option PlotLegends -> "Expressions" when the first argument to Plot is a single function. It works OK when I give ...
13
votes
3answers
448 views

Accessing Reduce from DSolve

When solving transcendental equations, Solve frequently warns us that inverse functions are being used so that some solutions may not be found. We also see that ...
13
votes
1answer
290 views

Count number of sublists with a total not greater than a given max

Suppose I have a list of positive integers: data={1, 1, 2, 3, 3, 3, 5, 5, 5, 7, 7, 8, 8, 9, 10, 10, 12, 16, 23} I want to count the number of subsets up to ...
13
votes
4answers
1k views

How can I extract the maximum value from a Histogram?

In Mathematica 8.04 I've created a histogram of returns on a stock using: ...
12
votes
4answers
347 views

Elegant high precision `log1p`?

Sometimes it is hard to understand how numerical expressions are evaluated. I remember reading claims by Wolfram on how smart the Kernel is to evaluate expressions trees numerically by recognizing ...
12
votes
2answers
485 views

Replicating a discontinuous graph

I'm trying to replicate a graph from my math book for my notes as well as to learn Mathematica. I was hoping someone would be able to help me figure out how to add the open points to the graph, and ...

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