All Questions

0answers
7 views

Find Unconnected Subregions

If I have a region, how can I identify sub regions that may be disconnected, if any exist? region defines a rectangular region given two diagonally opposed ...
0answers
7 views

solving singular matrix

Hello I have a matrix that is singular, and i wanted to use linear solve to solve it but that doesn't work with mathematica. The matrix given as a list looks like this: matrix={{-4.41583, 0.203293, ...
0answers
10 views

parsed matrix not deleting elements in adjusted matrix

I have a matrix that has been parsed to delete certain rows and columns, as well as delete certain elements on the diagonal on the matrix. The problem is that it does this in theory when i take the ...
1answer
21 views

How to select a list from a list?

I have a list contains three vertices of a triangle. ...
1answer
12 views

Prevent Simplify from using cot

I have the following problem. I got a huge equation to simplify and in there are numerous $\cos(x)$ and $\sin(x)$ terms and now it happens that Simplify changes terms like $(...+\cos(x)*a+...)$ to ...
1answer
12 views

import from Excel adds a point to each number …How to get rid of it?

I import an excel file ...
1answer
33 views

Get rid of Error Function: How to get rid of sequential appearances of error function?

We have a function as e[t_] :=(E^(-t^2)) Cos[0.1 t] and we must evaluate below integration (However I used the variable x ...
1answer
24 views

BSplineSurface problem

Why does the result of this function is straight line.If problem is in the order of my points, what order is correct? ...
0answers
22 views

Find $\phi$ as function of $\theta$ for Villarceau circle in a torus

I want to see Villarceau circles made by the tip of a line rotating inside a circular torus. It is normally generated as intersection of a plane tangent to meridional circles and formulated that ...
1answer
63 views

Write Integer powers as products

I need to wirte all occasions of (a+b)^3,Ftp^2, Sin[th]^2, ...etc as (a+b)*(a+b)*(a+b), Ftp*Ftp, Sin[th]*Sin[th], ...etc ...
0answers
24 views

Help to numerically solve ODE

http://math.stackexchange.com/questions/912076/time-period-of-ode Trying to numerically compute the time period of an oscillation as suggested by Robert Israel, to check it with direct plot. ...
0answers
17 views

Using assumptions when calling Simplify from Collect

I am quite new to Mathematica, so please be patient ;) I have a very long equation that I have to sort for powers of a variable called e and that I want to ...
0answers
48 views

Polar Plot Confusion [on hold]

Make a Manipulate that places a green point on the rose r=a+Sin[θ] at the point {r[t] Cos[t],r [t]Sin[t]}. You do this by using ...
1answer
58 views

MathematicaPolarPlot Question [on hold]

Using this as an example PolarPlot[{1,Sin[3 θ]},{θ, 0, 2 π}] Now consider the family of polar curves r=a+Sin[3 θ] as we vary ...
1answer
42 views

Compiling If statement

I have this code: ...
0answers
36 views

Method options for DensityPlot and ContourPlot

What Method options are allowed for DensityPlot and ContourPlot? I am unable to find this ...
0answers
25 views

Background color does not display in InputField unless Appearance option is also specified

I get the same behavior for v.10.0.2 and v.9 with OS X (10.9.5) : No background color is displayed in InputField if I just set properly the option. For example, ...
1answer
85 views

How do I plot results of complicated calculations in Mathematica?

I am new to Mathematica and am struggling with making plots of how features of solutions vary with parameters. For example, I can find the eigenvalues and zeroes of a Sturm Liouville problem (showing ...
1answer
36 views

Reading parameters from file and use them as parameter of a function

Hi all: given the code ...
1answer
67 views

Time Series Analysis - How does it Difference?

In languages other than Mathematica (especially R) if you want to do any time series analysis, you must always difference the series according to some feature of the series in order to satisfy at ...
1answer
47 views

Unable to Discretize a Region

I'm trying to compue a mesh of full 2D region delimited by the a circle transformed with a Complex map. ...
1answer
57 views

(Tree) Graph Layout

I am trying to draw a graph in a tree-like form. I can't use TreeGraph because what I am drawing is not properly a tree (has loops) so TreeGraph won't draw it. Here is the code: ...
1answer
129 views

How can I improve ContourPlot to get smooth curve?

I am working on the ContourPlot to creat contour line of a InterpolatingFunction recently. This is my data. This is my simple ...
1answer
41 views

Normalize centrality measures

How I can normalise centrality measures? Can I use Normalize function? I give example of unnormalized measures ...
0answers
92 views

Can I define an axiomatic (Boolean algebra) system and prove theorems using Mathematica?

The general question is Can I define an axiomatic system and prove theorems using Mathematica? The more concrete one is about Boolean algebra. I consider this axiomatic Boolean algebra system ...
2answers
64 views

Headings, subheadings, text cells etc and Alt+n

This is a minor point but annoying. I have just upgraded to version 10.0.2.0 and discovered that you must select a bracket before doing Alt+1, or Alt +7 to make a cell a heading or text cell. This was ...
0answers
54 views

How to export a vector of vectors (Mathematica 8)? [on hold]

I would like to export the object type: { {{"a", "n", "y"}, {"a", "s", "k"}}, {{"b", "y"}}, {{"d", "a", "t", "e"}, {"d", "a", "y"}, {"d", "r", "y"}} } and then ...
0answers
30 views

How can I define a metric in xAct?

I'm using "xAct" package and I want to define a my metric, that is a non standard metric. For example, my metric is diagonal ...
3answers
184 views

Plot of Implicit Equations

I've read Cool Graphs of Implicit Equations recently. In the article, it mentioned a software GrafEq which can draw graphs of arbitrary implicit equations. For example, And I've tried several ...
1answer
54 views

Fitting higher order ARIMA models hangs, never completes

I'm working with some data that is 12 month seasonal. However, when I try to fit it to an ARIMA(12,1,3) for instance, my PC's CPU cranks up to 100% and the job never finishes. Here's some sample code. ...
2answers
73 views

Power[__] Pattern works like Level

I came across this case: ...
0answers
22 views

Remote Kernel configuration works in v9 but not in v10

I have both v9 and v10 currently installed on my computer (Windows 7). For reasons that are not entirely clear, if I create a new remote kernel in one version, it is accessible to the other; however, ...
1answer
80 views

How to check if Integrate solved the integral?

This seems something that must have been asked before, but I am not able to find something. Integrate does not return status nor throw error when it can't find antiderivative. It just returns the ...
0answers
46 views

What are the differences between these functions when used for NMaximize?

In short, the question is how to construct the function you want to optimize? ...
3answers
957 views

Buying a new computer (specifically for Mathematica)

My current computer is a MacBook Air, the mid-2011 version: 4 GB RAM, 1.7 GHz Intel dual core. It runs Mathematica 9 smoothly, but a bit too slowly for my taste. I use Mathematica almost exclusively ...
1answer
52 views

Shifting Columns in an Array Efficiently

I am trying to find a more efficient way to shift the columns of the partitions of an array according to a defined slope and fill in the shifted regions with zeros I have done it below but, I know it ...
1answer
36 views

Ordinary Least Squares (OLS) with RLink

I need to calculate the parameters b0, b1 and b2 in: ...
2answers
36 views

Inverse of function including hyperbolic cotangent [on hold]

How can I create a numeric function for the inverse of $y(z) =\coth{z}-\frac{1}{z}$, over the range of $y\in [0, 1]$ and $z\in [0, \infty]$?
1answer
40 views

Unit conversion is not simplifying units

I'm running into what looks like an error. ...
1answer
33 views

Multicolumn sorting with ordering functions and precedence

I am aware that the question of "how do I sort on a column" has been asked in various forms, most notably this one. While some powerful solutions have been presented, as far as I can find no one ...
0answers
53 views

How to define a two-variable sequence?

I would like to define the following function but I am having a problem. I would like Mathematica to "understand" what I mean by writing "+...+". For example, for large values for $n$ and $m$ it takes ...
0answers
31 views

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1answer
100 views

How to execute a notebook in background

I am developing an algorithm that take time to return results. I thought if I could run this notebook in background and continue to develop the rest of my work. It is possible to do that?
0answers
49 views

How to execute code on FrontEnd quit?

I would like to execute a block of code whenever the FrontEnd quits. I know about \$Epilog, but it seems that this would execute every time the kernel quits, which is not what I want. Does anyone know ...
0answers
34 views

Align axes in GraphicsGrid - with one rotated figure

I would like to align the axes of the three plots: g3, gPosteriorMarginalMu and gPosteriorMarginalSigma: ...
1answer
67 views

How to speed up execution of this function?

How can I speed up the execution of following function, specifically for larger values of n? ...
1answer
26 views

Package function not evaluating

I have a short package like this: ...
1answer
72 views

Is there any function in Wolfram Mathematica simmilar to fft.fftfreq (Python)

Here is an explanation of fft.fftfreq I have data with random noise: ...
1answer
31 views

Add a legend to a DiscretePlot - Version 8 [duplicate]

I have found several topics with legend issues but no answer to my problem. I have a function and I need to plot it for integers only (hence discrete plot) and then add a legend too. But ...
0answers
39 views

How to properly (efficiently) define a mixture distribution and optimize the likelihood?

To start with: ...

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