4
votes
1answer
170 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 ...
-4
votes
1answer
107 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 ...
1
vote
2answers
305 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 ...
4
votes
2answers
480 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: ...
0
votes
1answer
165 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 ...
8
votes
3answers
272 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}] ...
2
votes
1answer
103 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 ...
8
votes
2answers
548 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 ...
3
votes
3answers
381 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 ...
10
votes
3answers
699 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: ...
6
votes
1answer
245 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 ...
9
votes
3answers
681 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 ...
2
votes
1answer
133 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 ...
1
vote
0answers
48 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 ...
5
votes
0answers
174 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., $$(x \ne -1) \land (x \ne +1)$$ ...
1
vote
1answer
155 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 ...
4
votes
1answer
332 views

RefProp in Mathematica

RefProp by NIST is a program that calculates the thermodynamic properties of fluids. I need to call certain RefProp functions ...
4
votes
3answers
560 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 ...
6
votes
1answer
1k 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 ...
21
votes
3answers
347 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 ...
5
votes
2answers
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 ...
4
votes
0answers
138 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: ...
4
votes
1answer
204 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 ...
10
votes
4answers
766 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 ...
4
votes
1answer
99 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. ...
5
votes
2answers
878 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: ...
0
votes
0answers
70 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 ...
2
votes
0answers
77 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 ...
2
votes
0answers
154 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: ...
3
votes
2answers
490 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 ...
2
votes
0answers
178 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 ...
6
votes
1answer
151 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 ...
33
votes
5answers
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. ...
15
votes
2answers
296 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 ...
2
votes
1answer
63 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 ...
2
votes
1answer
93 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 ...
6
votes
3answers
381 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 ...
1
vote
1answer
723 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 ...
6
votes
1answer
171 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 ...
5
votes
1answer
839 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 ...
3
votes
1answer
207 views

Weird resampling when I try to export an Image

Mathematica language newbie here. I wrote the following code to quantize an image: ...
3
votes
1answer
1k views

Contour Plot in Cylindrical Coordinates

I'm trying to render an equation in the cylindrical coordinates, and I used the following codes: ...
0
votes
1answer
102 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 ...
27
votes
3answers
685 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 ...
1
vote
1answer
158 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 ...
11
votes
1answer
224 views

FindInstance returns Indeterminate in version 9, but not in 8

Here is a trivial system of equations in three unknowns for which FindInstance obtains a solution: ...
13
votes
2answers
1k views

Mathematica color schemes for the colorblind

Does Mathematica have a graphics option that makes plots intelligible for people with colorblindness?
2
votes
1answer
95 views

Notation not recursive enough?

My notation is not recursing enough. For example, Notation[W[a_ | b_] ⟹ foo[a_, b_]/foo[b_]] Notation[W[a__, b_ | c_] ⟹ W[a__ | c_]W[b_ | c_]] Then ...
0
votes
0answers
38 views

Correspondence between eigenvectors and eigenvalues [duplicate]

Let us say I have a matrix h (2x2). Now, I want to get the eigenvectors and eigenvalues of my matrix h: ...

15 30 50 per page