# All Questions

783 views

### How to apply a permutation to a symmetric square matrix?

Given a symmetric square matrix, how can I apply a permutation to the rows and columns (i.e. the same permutation to both the rows and the columns) such a way that the new structure of the matrix ...
319 views

### Centrality measures for single nodes

I am producing a graph, generated by a list of adjacent nodes. (The list looks like {1 ->583, 1->2977, 2->14, 4->1293, 5->221, ...}. Each node of my ...
904 views

### Changing variables algebraically

Suppose one has two functions, $y(x)$ and $z(x)$, and one seeks to obtain $y(z)$ by substituting $x(z)$ into $y(x)$. Can this be done in a single step? Or must $z(x)$ first be inverted independently? ...
1k views

### Mathematica Can't Evaluate This?

I am trying to find the inverse function of $\frac{\ln{x}}{x^2}$ in Mathematica. I am using the Solve[] function to find the inverse (yes, I know about ...
1k views

### Bold face formatting for vectors instead of overarrows like latex \mathbf{}?

OverVector can be used to make a symbol look like a vector in text sections of documents. I happen to like bold symbols for vectors better, as in latex ...
526 views

### How to repeatedly show variations on a plot

I would like to show graphics repeatedly with changes in parameters. Neither of the following show anything. Nor do they give an error message. ...
263 views

### Brackets in output make unable to use output to identify matrix element

I'm trying to write a code where each matrix element swaps with a randomly selected neighbor (cardinal directions only) to redistribute the matrix. So far I've been able to replace an element with its ...
2k views

### Kramers-Kronig in Mathematica

I am trying to calculate the change of the refractive index from the change of the absorption coefficient using the Kramers-Kronig relations, in Mathematica. ...
813 views

### Formatting output of OpenAppend[] to match what Export[data,file,“.csv”] would output?

I have a large data set that gets exported to a .csv file. Export[data,filename,"csv"] is extremely fast and formats the data in a nice JMP-friendly manner. ...
440 views

### Considerations when determining efficiency of Mathematica code

I have two segments of code that do the same thing and I want to determine the which is more efficient. What are the considerations when determining efficiency of Mathematica code? ...
933 views

### How do I find the elements in a list that return the highest value for a function?

Suppose we have a list of values and a function f. I want to find which of the elements maximizes the return value of the function in Mathematica. Let call the ...
541 views

Is it possible to add some customization code to the front end, so that when all cells have finished evaluating, some user code can be run? Background: I'm currently running some Mathematica programs ...
2k views

### How do you define the domain of a plot?

How do you define the domain of a plot? For instance, if I want to plot a standardized bivariate normal density function (with $r=0$), how do I specify the domain to be $[-3,3]$?
491 views

### Reading from a stream of strings and numbers delimited by commas

I am trying to read from a stream of strings and numbers delimited by commas similar to the way I have read from a stream of strings and numbers delimited by spaces. Example delimited by spaces ...
103 views

### is there an equivalent of “show” steps? [duplicate]

Possible Duplicate: Get a “step by step” evaluation in Mathematica In wolfram alpha, when preforming for complicated integrals there's a 'show steps' option that explains how ...
300 views

### How to write a function-defining function which stores the function arguments in a stack?

I have a function-defining function SetAttributes[DefFn, HoldAll]; DefFn[f_[args___], body_] := f[args] := body; I am trying to modify this function to record ...
168 views

583 views

### What causes Manipulate to stop evaluating expressions?

I'm working on a N-body simulation within Mathematica, and currently I have something along these lines: ...