3
votes
0answers
39 views

Behavior of $PreRead in Kernel

I am interested in making a simple accounting style line calculator that allows me to interact with it something like this: ...
2
votes
1answer
260 views

Normalize the PlotLegends and z values for two DensityPlot

I'm trying to compare two DensityPlots: ...
0
votes
2answers
153 views

List Plot 3D the same colour scale

I have a transient problem of pressure disipation. I want to plot severals 3D plot but I have a problem with colours. Case: One of my ListPlot3D presents pressure ...
2
votes
1answer
138 views

Integration of a rational function

I am trying to solve the following rational integral (I got assistance here): $$\int_{-\infty}^{\infty}{\frac{a+x}{b^2 + (a+x)^2}\frac{1}{1+c(a-x)^2}}dx$$ where $\{a, b, c\}\in \mathbb{R}$. I would ...
15
votes
7answers
6k views

Mathematica: finding min/max in list

I have a list of coordinates like this one: {{x1,y1},{x2,y2},{x3,y3},...,{xn,yn}} I need to get the minimum and the maximum of all x-values and the minimum and ...
2
votes
1answer
70 views

Use Initialization Cells to open a CellGroup

I would like to use "Evaluate Initialization Cells" to open a CellGroup in a notebook. However, the following code doesn't work if placed in an initialization cell: ...
1
vote
1answer
154 views

Manipulate not accepting default values

I have pasted my Mathematica code below. For some reason, the default value for h, or Δx, while set to 4.5 in the code, keeps displaying at -4 instead. I have been over and over this example, and I ...
3
votes
2answers
205 views

How to replace Do loops by Inner

I need to replace Do loops by something else because it takes forever with big programs. I have been hinted towards Inner, but ...
0
votes
1answer
362 views

Upper bound for x

I want to ask a question about Reduce. I have a function, say f[x]. When I use the command ...
1
vote
1answer
297 views

Concerning ShowLegend in Mathematica

I found a code for Mie Scattering from 2007, written for Mathematica. I have edited it quite a bit, since there are package definitions that we don't need, etc. But I am having difficulties ...
4
votes
4answers
1k views

How to plot filling under a curve?

I want to mark critical areas for statistical test on the plot. How can I do this? This: ...
5
votes
2answers
343 views

Simplify — is this simplest result Mathematica can provide?

I have a question about Simplify: When I do a simplification the returned result is not as simple as I want. When I ask for the Norm of an complex expression, ...
2
votes
2answers
154 views

Substitution to write out powers of expressions

I am looking for a substitution command which will write out powers of expressions like this: $$\frac{a ~b^3~ c}{d~ e^{3/2}~ f^2}\to \frac{a ~b~b~b~ c}{d~ e^{1/2}~ e^{1/2}~ e^{1/2}~ f~f}$$ ...
3
votes
0answers
145 views

Mathlink and multithreading

In order to make my computations faster I have developed a C/C++ application calling Mathematica kernel and performing many operations using Mathematica functions for equation solving. Now I want to ...
22
votes
3answers
591 views

Common subexpression from two expressions

I am working with some unpleasantly tedious polynomials, which need to be manipulated in various ways (integrate with respect to some variable, differentiate with respect to another). Since these ...
0
votes
1answer
215 views

DAE - varying initial conditions

I want to solve a DAE-system and I want to vary more than one initial conditions and to manipulate them. I looked here: Putting NDSolve into ParametricPlot But it does not work: ...
3
votes
0answers
128 views

Is this result wrong because of calculation time? (and more questions about Assumptions)

I am confused with the Integrate Given by Mathematica. First let's see a one-dimensional case: ...
13
votes
1answer
614 views

What is $ sign in Mathematica?

Is it a special sign or it can be used as anything else? For creating variables for example. $x=4
23
votes
4answers
1k views

What is the fastest way to count square-free words?

Background A word is a string of letters in an alphabet. A square-free word has no adjacent repeating substring. For example, (in the ternary alphabet of {0,1,2}) the words 00, 012121, and 0212012021 ...
7
votes
3answers
276 views

Making large tables easy to read with frozen headings and scrollbars [duplicate]

I would like to represent a table containing a large amount of information in such a way that I can (a) use scrollbars and (b) have table headings that don't scroll off the screen [just like the Free ...
1
vote
2answers
414 views
1
vote
1answer
209 views

How to store a SparseArray? [duplicate]

How to Export/Write a SparseArray? How to Import/Read a SparseArray? Is it always stored as a normal array? How can it be stored in a dense form? Is a numerical SparseArray different to Export/Import ...
7
votes
2answers
868 views

How can I fill under a function in a plot just to right of a specified vertical line?

How do I plot a normal curve with filling under the curve and to the right of a vertical line. I would prefer that the vertical line starts at the x-axis and stops at the plotted curve. Basically ...
8
votes
3answers
360 views

How can I prevent kets to from growing too large?

In TraditionalForm, Mathematica formats kets incorrectly in certain expressions. For example, if used in a summation with indices indicated, a ket becomes too ...
4
votes
2answers
319 views

Cannot call custom function loaded from script using C/C++ MathLink

I am using MathLink with C/C++ on a Unix system in order to call a Mathematica (version 9) function and get the result. The function I need to call is a personal function of mine ...
8
votes
3answers
492 views

How do I make Reduce yield all solutions explicitly?

Say I want to do the following: Reduce[ x+y+z==1, {x,y,z}, Modulus -> 7 ] then I get a solution with parameters, C[1] : ...
4
votes
2answers
281 views

Override Equation structure change in mathematica - CopyToLaTeX

I am writing my thesis, and when I do copy to LaTeX from Mathematica, it changes the equation variables and also it rearranges the structure of the original equation. How can I override that ?? ...
2
votes
0answers
39 views

NIntegrate/NSum with parameters [duplicate]

I'm trying to calculate a continuous integral within a discrete integral. Something similar to this (yet more complex): ...
1
vote
1answer
104 views

Given a list of date and value pairs, efficiently sum the values by date

I have a list of date & value pairs. There can be multiple entries for each day. Sample data can be generated with the following: ...
6
votes
1answer
166 views

Importing images from the web using ImportString & URLFetch

I can bring images from the web using the Import command like this: Import["http://blog.wolfram.com/wp-content/uploads/2008/06/se-30.jpg"] Sometimes the web ...
2
votes
2answers
409 views

I get weird <<…>> symbols in my output — what does it mean?

After I input the following: data = Table[{3 + i + RandomReal[{-3, 7}], i + RandomReal[{-2, 5}]}, {i, 1, 20}]; model = LinearModelFit[data, x, x] I got ...
0
votes
0answers
31 views

Expressions like <<1>> [duplicate]

In a function where I call the Maximize function, I am getting an error that says ...
0
votes
1answer
198 views

Integrate of Heaviside Function returns an error answer

I try to evaluate an Integral of a Heaviside function, but it turns out with an erroneous output(zero). Here is my integral: ...
3
votes
4answers
473 views

Importing or reading data in binary format 212

I have a binary data file in format 212, and I want to import the file into Mathematica. How do I read or import binary format 212? I almost have no direct experience of working with any binary ...
1
vote
1answer
138 views

How can I change the Graph required data such as EdgeWeight,VertexWeight,EdgeCapacity,VertexCapacity in the Graph?

I asked this question in different form and because I couldn't receive the proper answer so I have to change my question.I know that was my fault sorry.I need to change the Matrix Data of nodes and ...
18
votes
2answers
800 views

3D orbits and inaccuracy over time

I wrote a little program to use Newton's Law of Universal Gravitation to animate 3 planets orbiting a central star, but I have run into a problem. Here is the code that I used to create the program (I ...
9
votes
2answers
368 views

InverseSeries of multiple variables and multiple equations

CONTEXT Let us consider a bit of the Universe in which we draw spheres (see a high resolution image here). Astronomers have shown that the density within these spheres could be predicted quite ...
2
votes
0answers
149 views

Exporting plots

I want to export a plot which includes curve fitted to a multiple data set. shortly ( I use autolegend function Here ) ...
1
vote
1answer
191 views

Safe values of $\mu$ and $\sigma$ when randomly sampling from a Log-Normal Distribution?

I believe I'm obtaining overflow errors when randomly sampling from a log-normal distribution with the command: RandomVariate[LogNormalDistribution[μ, σ], 1] ...
1
vote
3answers
203 views

How to collect/reduce with respect to multiple variables?

I have this code: a == b + c + d - e Is it possible to collect or reduce this expression into this: c + d == a + e - b ...
8
votes
3answers
153 views

How can I use the overhang argument to Partition to avoid using PadLeft and PadRight here?

Say I have a list of values v = {v1, v2, v3, ... }. I need to partition these values to perform operations with a sliding window (think ...
13
votes
4answers
378 views

How to separate paths from the output of EdgeDetect?

I have been trying to find a way to separate the various closed paths that can be output by EdgeDetect. For example, taking the output of: ...
5
votes
1answer
206 views

How do I place a graphical marker (box, circle, …) in a MatrixPlot?

I'm trying to locate minima / maxima in matrices on a heat map. So I have my 2D matrix and did a MatrixPlot, and I can find the position of the smallest value. ...
0
votes
2answers
451 views

Finding max, min, and closest root of two dimensional data

I have some data that is two dimensional (traditional (x, y) format) as so: var = {{x1, y1}, {x2, y2}, {x3, y3}} I would like to search through that large list ...
11
votes
4answers
4k views

Using Export[] sends the file where?

I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can't find the file! Where is it ...
0
votes
2answers
237 views

How can I give graph required data with GUI?

Consider that I have the simple graph of ...
18
votes
3answers
1k views

Visualizing a Complex Vector Field near Poles

I've been playing around with a visualization technique for complex functions where one views the function $f: \mathbb{C} \rightarrow \mathbb{C}$ as the vector field $f: \mathbb{R^2} \rightarrow ...
11
votes
2answers
280 views

Where to begin? [duplicate]

I was looking at the Mathematica website today and just decided to buy the software. I've spent too much time juggling annoying symbolic expressions by hand that actually learning to do things with a ...
5
votes
1answer
910 views

How to draw some 2D curves in a 3D plot? [duplicate]

I want to plot several 2D curves (Sin[x] at y=0, Cos[x] at ...

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