# All Questions

447 views

### Issue with the NDSolve code

With this procedure, one may determine an eigen-value function $R(a)$ for any given $\Xi$ (say 0, 25, 50, 75, 100) ...
217 views

### Create Slider to start/stop/move Point

I want to be able to start, stop, and move the dynamically moving point simultaneously in both animations. The "PlayPauseButton" in the animations only controls the given animation. Indeed, I want ...
150 views

417 views

### How do I label contour lines that are superimposed on a 3d plot?

I need to generate a 3D plot of a function, say $z = \sin(x)\cos(y)$, with contour lines drawn at specified intervals. I also want to label each contour line with its $z$-value. I have discovered how ...
324 views

### ListDensityPlot crashes the kernel

ListDensityPlot[ Flatten[Table[{i, j, Sin[i + j]}, {i, 1, 20}, {j, 1, 20}], 1]] gives the expected result, but a linear scale crashes my kernel (please save your ...
848 views

### Is there anything like a C pointer (or returning a reference) in $Mathematica$?

I want to do in Mathematica what the following does in C. ...
100 views

### Using quantifiers with free indices as declarative conditions in equation solving

This is a toy example: Is there a way to rewrite Reduce[{Norm@{c[1], c[2], c[3]} == 1, 0 <= c[1] < c[2] < c[3]}, {c[1], c[2], c[3]}] ...
311 views

### How to restore default seed generation in SeedRandom[] when specifying method?

I want to generate low-discrepancy sequences and for that purpose I use SeedRandom[], like: ...
130 views

### Slow NIntegrate over complicated domains (sometimes)

This is no longer a problem with Mathematica 10.* where I can use regions to do the integrations Overview I have a very large matrix I need to calculate where each element requires the integration ...
162 views

### Reading between blank lines in external data files

I have an external data file with several columns and thousands lines of data. For the sake of this question, let's assume that we use ...
439 views

### How to draw the image of a circle under the action of a transformation of the phase flow?

How to draw the image of a circle $x^2+(y-1)^2<1/4$ under the action of a transformation of the phase flow for the equation $\dot{x}=y,\ \dot{y}=-\sin x$? Here $\dot{x}$ means $dx/dt$. Any help or ...
299 views

### Can I generate a “piecewise” list from a list in a fast and elegant way?

Suppose we have a number list a: n = 1000000; a = RandomReal[{0, 1}, {n}]; We want to generate a list ...
193 views

### Defining and evaluating new continuous distributions based on Mathematica's distributions

A number of functions operate with Mathematica's set of distributions e.g. Through[{Mean, StandardDeviation, Variance}[UniformDistribution[{umin,umax}]]] which ...
523 views

### How to express an expression with only ArcTan and ArcTanh?

I have an expression which is simply (j/k) x^(j/k) LerchPhi[x,1,j/k)] where 0 < j < k. Manually I have been able (...
111 views

### Operations on expressions within Hold [duplicate]

I want to convert {Hold[1 + 2], Hold[3 + 4], Hold[5*6]} into Hold[{1 + 2, 3 + 4, 5*6}]. I have tried ...
122 views

2k views

### Create simple table with function of column values

I just want to create a simple table: Three input columns, one output column Call the inputs {x,y,z}, each can take values ...
992 views

### Change font for the whole notebook

Is there any option Mathematica's preferences to change the font for the whole notebook? I know how to change the font of individual cells.
Update: Starting from V10.0 the build-in Moment is fast enough for practical use. I have a multinormal distribution with covariance matrix $\sigma$ and zero mean....