# All Questions

1answer
105 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
60 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
197 views

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

May I request for your indulgence, to enable Villarceau circles visualization made by the tip of a line rotating inside a circular torus if possible based on unification of parameters. EDIT2: ...
1answer
125 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 ...
2answers
168 views

### Help to numerically solve ODE

http://math.stackexchange.com/questions/912076/time-period-of-ode Trying to numerically compute and compare the time period of an oscillation with the analytical solution suggested by Robert Israel. ...
0answers
67 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 ...
1answer
79 views

### MathematicaPolarPlot Question [closed]

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
82 views

### Compiling If statement

I have this code: ...
2answers
192 views

### Method options for DensityPlot and ContourPlot

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

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

I get the same behavior for v10.1.0, 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 ...
1answer
240 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
67 views

### Reading parameters from file and use them as parameter of a function [closed]

Hi all: given the code ...
1answer
225 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 ...
3answers
145 views

### Trouble Discretizing a ParametricRegion; Joukowsky Map and Wing Profiles

I'm trying to compue a mesh of full 2D region delimited by the a circle transformed with a Complex map. ...
1answer
112 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
239 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 ...
2answers
97 views

### Normalize centrality measures

How I can normalise centrality measures? Can I use Normalize function? I give example of unnormalized measures ...
0answers
154 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
136 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
72 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 ...
4answers
646 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 ...
2answers
172 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
87 views

### Power[__] Pattern works like Level

I came across this case: ...
1answer
320 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
100 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
74 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? ...
4answers
2k 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
71 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
75 views

### Ordinary Least Squares (OLS) with RLink

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

### Inverse of function including hyperbolic cotangent [closed]

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
111 views

### Unit conversion is not simplifying units

I'm running into what looks like an error. ...
1answer
107 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
73 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
37 views

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1answer
132 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
95 views

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 ... 0answers 74 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 99 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 49 views ### Package function not evaluating I have a short package like this: ... 1answer 169 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 70 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 58 views ### How to properly (efficiently) define a mixture distribution and optimize the likelihood? To start with: ... 2answers 250 views ### How can I use ContourPlot to creat streamline for a free surface domian: proper arrow orientation and correct domain? I get into trouble when I use ContourPlot to draw streamlines in a free surface flow domain. This is my data.The data are a little bit big, please be patient. ... 1answer 150 views ### ParametricPlot3D: The Mesh shows some unexpected wires to the origin. How to remove them? In the code below a hexagonal shape is defined and plotted. The ParametricPlot3D shows the hexagonal design almost as intended. However, the mesh makes some strange "wires" to x=y=0. This is ... 2answers 170 views ### Specifying and solving a PDE on an L-shaped domain I wish to solve Laplace's equation with Dirchlet boundary conditions on an L-shaped domain as described here http://www.inf.ethz.ch/personal/tulink/FEM14/Ch1_ElmanSyvesterWathen_Ox05.pdf I know how ... 1answer 132 views ### 'eps' equivalent in Mathematica In Matlab there is a function 'eps'. eps Spacing of floating point numbers. D = eps(X), is the positive distance from ABS(X) to the next larger in magnitude floating point number of ... 1answer 42 views ### How to share ChartLegends among multiple BoxWhiskerCharts in GraphicsGrid? First, create two BoxWhiskerChart: box1 and box2 ... 1answer 69 views ### Joint Distribution with a Constant I would like to simulate from a joint distribution multiplied by a constant. e.g. 3*NormalDistribution[0,1]*NormalDistribution[1,1] I tried using something like ProductDistribution but that doesn't ... 2answers 55 views ### PEANO Integers using successor function I'd like to define the integers and operations on it by using terms. Starting from zero->init[] and nth->succ[n-1th] where succ[] is the successor function. I ... 4answers 165 views ### Minimizing a function with a constantl > 0$I'm VERY new to Mathematica and would like some help with minimizing a function. $$f(x) = \frac{1}{2} \sqrt{\frac{\left(l^4+x^4\right)^2}{l^4 x^2}}$$ I want to find which$x-value\$ (probably ...

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