# All Questions

267 views

### Interpolation on large 2D list results in erratic function

Previously, I've had problems with Mathematica interpolating and plotting 3D lists, but I finally managed to do so by rescaling the x and y-axes with the help of the methods proposed here. Now my ...
408 views

### Using Manipulate to vary the frequency of a sound produced by SoundNote[]

I have tried various ways to combine Manipulate and Sound/SoundNote that would allow me to vary the frequency of a sound while it is being produced. The addition of Dynamic didn't help, but did ...
141 views

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175 views

### Plot3D list elements

I've been having some trouble with Plot3D. I have a quite complex function of two variables (actually three but the first one doesn't matter) that returns a list ...
110 views

### Exporting data from different notebooks to a common file

I am doing some calculations from different notebooks. I need to export the results from all those notebooks in columns of the same file, like a1 b1 c1 a2 b2 c2 a3 b3 c3 . . . where a, b ...
349 views

### Select rows from table by keys

I am looking for a way to iteratively select all sublists with the same ID (my 1st column, residual columns are AbsoluteTime entries). First, I obtained the list of ...
534 views

### Transparent Cylinder with Dashed Edges only

I would like to have that kind of cylinder with Dashed edges (including the bellow inner ring): I've been trying that: ...
169 views

### Interpolating a Bivariate Polynomial over a Finite Field

Let $F=GF(p)$ be a finite field, $p$ prime and write $F^\times=\{x_1,\ldots,x_n\}$. I'm trying to implement an earlier version of Sudan's list-decoding algorithm for Reed Solomon Codes ...
284 views

### Reduce the output from tuples by including symmetry?

I need all the possible 3x3 binary tensors, but I'd like to have this account for symmetries. I've started by using the Tuples command. Tuples[{1, 0}, {3, 3}] ...
107 views

### Cell background color changes cell layout

When I change the background color of a cell like in the colored cells become slightly indented and their line spacing is increased. How can I change the cell background color while keeping the ...
619 views

### OpenSCAD like functionality with Mathematica?

I keep seeing reference to use of Mathematica as a CAD tool (for instance: http://www.makerbot.com/support/guides/design/). I'd like to use it as such if feasible, but I'm having trouble locating ...
402 views

### Horrific Looking Contour Integral in Mathematica Plot:

I'm attempting to display the geometric meaning of a contour integral but as you can see, the typesetting of the contour integral (created via the Epilog function) looks awful because the contour ...
780 views

### Why doesn't my script work when I redirect stdout?

I'm using Mathematica Home Edition 9.0.1 on Mac OS X 10.8.2. I have this script: ...
272 views

### Launching remote slave kernels on HPC causes slow down

I had a post earlier regarding how I can run Mathematica at a HPC cluster (running PBSpro) by having a single MathKernel launch ...
760 views

### Dashed mesh behind 3D object

I am trying to create a simple, almost transparent 3D sphere with a mesh that is made of solid lines if they are on the front surface (i.e. if they are directly visible) and of dashed lines if those ...
135 views

### Avoiding the re-evaluation of a RegionPlot3D

Is there a simple way to save the output from RegionPlot3D so as to avoid re-evaluating when the notebook is re-opened and Show ...
49 views

### Definition of differential operators [duplicate]

I am curious how differential operators are defined in Mathematica. More specifically, if the Laplacian function wasn't available, how would one go on to define such a function in Mathematica directly ...
189 views

### Convert logical relational expression to / from disjunctive and conjunctive forms?

I would like to convert logical relational expressions in disjunctive form, e.g., $$(x \lt -1) \lor (-1 \lt x \lt +1) \lor (x \gt +1)$$ into conjunctive form, e.g., $$(x \ne -1) \land (x \ne +1)$$ ...
160 views

### Solving a system consisting of an ODE and a non-differential equation

I would like to solve the following system of equations: y'[t] == x[t]*y[t] - x[t]; 10 == x[t]*y[t]/(x[t] + y[t]) + x[t]/(x[t] + y[t]^2) Is there any way to ...
356 views

### RefProp in Mathematica

RefProp by NIST is a program that calculates the thermodynamic properties of fluids. I need to call certain RefProp functions ...
630 views

### Graphical Plots of PDF and CDF

I have a joint density and distribution function that I want to plot in a meaningful way, (i.e., want to be able to see how the functions behaves as changes in x and y happen simultaneously. If ...
2k views

### Spiral pattern and Fibonacci numbers

I'm want to generate a 2D spiral pattern like the the one shown in the following figure. I can generate the spirals one by one, but I think there ought to be a more efficient method for generating ...
361 views

### Efficiently appending points to a NearestFunction

I have a program which works with a list of points (in 3D, but it could be in 1D as well, it won't make a difference). Within a loop, it keeps adding new points to the list. To calculate the ...
3k views

### Solving a tridiagonal system of linear equations using the Thomas algorithm

I'm trying to write a function that can solve a tridiagonal system of linear equations using the Thomas algorithm. It basically solves the following equation. (Details can be found at the Wiki page ...
141 views

### Version 8.0 integrates but Version 9.0.1 doesn't

I am trying to run the following integral in version 9.0, but it fails: ...
215 views

### Manipulating a Graphics3D output with a large number of geometric primitives

I'm attempting to view and rotate a Graphics3D object with a very large set of geometric primitives ($\approx 10^6$ objects such as spheres or lines), and everything is functioning very slowly. Are ...
921 views

### How to draw a higher-genus surface

NB: By higher-genus surface, I mean a closed orientable surface of genus at least 2. This question has come up before on math.SE, and even MathOverflow, but most posters suggested using either ...
103 views

### How can PixelConstrained be emulated with DensityHistogram?

This DensityHistogram doesn't display very well. Some bins are shown much larger than others and, oddly, empty bins appear to be drawn smaller than occupied bins. ...
973 views

### Exporting a .xlsx file with about 500 columns

When I want to Export["text.xlsx", data] where data is a matrix with 500 columns and 10000 rows, I get the error message: ...
72 views

### How to define the tangent gradient operator? [duplicate]

I would like to define a new differential operator that is the tangent gradient for a curve $\Sigma$. This is defined as $$\nabla_\Sigma=\mathbf{P}\nabla$$ where $\mathbf{P}$ is the projection ...
78 views

### SetDelayed and avoiding function calls through memoization [duplicate]

I am fairly new to Mathematica. I am working my way through a number of books. I have been looking at the use of SetDelayed and want to confirm that my ...
165 views

### Problem when merging cells including commentary

This is a more of a problem report than a question. When merging the two cells Cell1: foo (*foobar*) bar and Cell2: ...
630 views

### How to change default settings of cell formatting?

I find font size of Text cells too small and I like displaying them with background colour... I've read this question and learned about ...
181 views

### Solving $k\log(n) - k\log(k) \leq u$

How can I persuade Mathematica to help me find solutions to the inequality $k\ln(n) - k\ln(k) \leq u$ over the reals, assuming $u \geq n \geq k \geq 1$. When I evaluate ...
164 views

### Go to definition of symbol/variable

Is there any easy way of directly jumping to the definition of a Variable like it is implemented in some good IDEs? Currently I have to search manually (ctrl+f) through the whole workbook to find it ...
2k views

### Distribution of random points in 3D space to simulate the Crab Nebula

I'm generating some 3D models of planetary nebulae and supernova remnants for Celestia, a free OpenGL astronomy software. Currently, I know how to do it with random points inside a spherical shell. ...
307 views

### Inconsistent results from equivalent integrals

Why is Mathematica returning different values for these two integrals: I am just being introduced to complex integration, so it's possible that I have a misunderstanding of how this works, but in ...
67 views

### Unique[] in RHS of rule

I have a function, explicit that takes dot product of two symbols, and replaces it with repeated dummy indices generated by ...
95 views

### Graphing the amount of time a function takes

I know I can find out the amount of time a function takes to run like this: In:= function1[100] //Timing Out:= {0.043334, Null} How can I graph this over a set ...
437 views

### A deterministic function to generate a random number

Using Mathematica, I need to define a function of one integer variable that generates the same real number in the range 0 to 1, if it is called with the same argument, but gives a different real ...
926 views

### Plotting with Units

I'm trying to get Mathematica to plot with units, but I'm having some trouble. Below is a minimal example of trying to plot y = x, where ...
180 views

### Does pass-by-value affect the performance of function calls?

I only have a little coding experience in C, and I remember I was told that pass by reference is more efficient than pass by value since the parameters don't need to be copied. Since there is no pass ...
965 views

### OpenCL Dot Product

I have to calculate billions of dot products. My current implementation uses Compile to generate C code and it's very fast (10s ...
213 views

### Weird resampling when I try to export an Image

Mathematica language newbie here. I wrote the following code to quantize an image: ...
1k views

### Contour Plot in Cylindrical Coordinates

I'm trying to render an equation in the cylindrical coordinates, and I used the following codes: ...
115 views

### Strange function definition result [duplicate]

I'm relatively new to Mathematica, and I'm trying to define a function f(k) that would do the following: For any positive integer $k$, a finite sequence $a_i$ of fractions $\frac{x_i}{y_i}$ is ...
766 views

### How can I make points “glow”?

I have a set of points in the plane which I would like to have "glow". I would like for each point to glow individually and I would also like some increase in the intensity corresponding to an ...
183 views

### Problem with large values in ParametricPlot

I've got a question quite similar to No 18163:Problem with high parameter values in ParametricPlot, but the solution of that problem did not work for me. So I hope you may have another tip. I want to ...