# All Questions

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### Large scale linear programming (Data imported from .mat file)

I tried to run a large scale linear programming with mathematica. I entered the code below: ...
190 views

### 2D Markov Process

I have a homework project. I need to analyse a gambler's ruin where there are 6 possible outcomes of every wager with corresponding probabilities and payoffs and the gambler may vary the wager (say ...
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### Applying a general formula

We are a group of students who are struggling with transforming this formula to run in mathematica. In fact there are many formulas that we are struggling with, but if we are able to see how this is ...
111 views

### How to Override the Head of a Symbol

I was wondering if it is possible to override the head of symbols/operators. As a motivating example if I run: Then Ket will be returned. But lets say I want Bob to be returned instead of Ket. Is ...
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### Does Mathematica compute free-form-input on Wolfram servers?

I've just started to use Mathematica and I'm using the free-form input a lot. The computation time for simple problems seems to take a lot of time and my CPU isn't really used at all. I first thought ...
114 views

### Difficult parametric function

I've got this strange parametric function and I want to implement it on Mathematica. I know that I could use Excel and calculate it, but my database is quite large and I want to do some reproducible ...
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### StreamPlot Label for General Parameter

I have a simple DEQ: $$y'(t) = y + C$$ for a constant $C$. It turns out that the equilibrium point of this DEQ is $-C$. I can use the StreamPlot command to plot ...
480 views

### Generating social network graph from a CSV file

I am new to Mathematica and wanted to generate undirected graph for data sets that show the relationships of organizations with each other. The data is in a square matrix. The cells of the matrix ...
195 views

### Sorting lists element by element [duplicate]

I have a problem regarding list sorting. Let's say I have a list of lists obtained using Subsets[], of the form ...
240 views

### Generating a random tree of given cardinality, depth, and labeling

For demo, exploration and teaching purposes, I would like to be able (and asking you for help) to generate these special instances of trees: For given: N - number of nodes in the tree D - depth of ...
201 views

### Combining Newtonian 3D N-Body Simulation Output and Earth Sphere

I'm trying to figure out how to make a simulation whereby two satellites orbit Earth, but have run into a little bit of a snag. I have a solution to the system of ODEs for the n-body output, and I ...
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### How to normalise a line in mathematica

I'm working on creating a line plot from a histogram, as in the following: ...
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### Export notebook to HTML produces low resolution GIF

I have equations written in my notebooks as text (the cells set as Format -> Style -> Text). When exporting the notebook to HTML (File -> Save As.. -> HTML) with the GIF option (the default) an HTML ...
317 views

### How to efficiently mask an image?

I want to extract/cut out a part of an image. Since my mask is not rectangular I want to set pixels that are not masked to zero (black). My current approach is something like this: ...
427 views

### Draw grid lines at multiples of k

Here is a beginner's question: when creating plots with mathematica, I want the grid lines to be at multiples of a constant value. E.g. in the following plot, the vertical grid lines are at multiple ...
140 views

### Extract the generating curves from a Graphics3d returned from RevolutionPlot3D

I have a plot g = RevolutionPlot3D[{Sin[t], t}, {t, 0, π}, {θ, -π, π + 3 π/4}]; Is it possible to extract the generatrices (generating curves) from ...
336 views

### Recognize simple shapes in an image and color them randomly?

I have an image of polygons built from a polar function (see below). I'd like to color each triangle or quadrilateral a random color. Firstly, I'm not sure how to separate the simple shapes. ...
234 views

### How to choose MaxStepFraction for optimal speed of NDSolve

I'm trying to use NDSolve to solve a 1D Schrodinger's equation, and it seems that MaxStepFraction has huge effect on the ...
223 views

### The second argument of Signature

I've noticed that Signature can have an undocumented second argument. What does it do? Signature[{1,2,3,4}, ?]
492 views

### Plotting time data with axes labels and point labels

I am trying to create a set of commands to automatically create clinical lab value plots. Using time is my major issue here. It is hard to dynamically reference the different point positions to ...
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### Re[x] vs. x ∈ Reals in the context of Assuming

Let's say that $x$ is some real valued number $>0$. Are the following commands interchangeable in the context of using Assuming? ...
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### When are If, Piecewise, Switch, and Which interchangeable and when are they not?

Experimenting with joint dependent distributions via the TransformedDistribution function, I used the following to derive a distribution where the second variate is ...
306 views

### A Bessel & Struve functions related integral

I try to numerically compute this integral and I don't figure out why on earth Mathematica is not able to do it. Is my input correct? Does it possibly have a closed form? ...

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