# All Questions

208 views

### Solving with DSolve recursively

I need to find $f(x,n)$ in the interval [0,1] defined by recursion, $$\frac{d f(x,n+1)}{dx} = f(x,n)$$ with boundary conditions $f(0,n+1) = 1$ and $f(x,0)=1+ x$ Using ...
206 views

### ListContourPlot is blank

This is probably very simple. I want to do a simple ListContourPlot. ...
705 views

### Splitting strings into letter keys and integers

I have strings of the following form: string = "ABC123DEFG456HI89UZXX1"; Letter keys of variable lengths are followed by (positive) integers. I want to get this ...
312 views

### Efficient method to generate Tridiagonal 50 by 50 Matrix? [duplicate]

I'm looking to generate a tridiagonal 50x50 matrix, ideally without using loops. Suggestions on most efficient code for this?
254 views

### Incorrect result while using SemanticImport for CSV file import

I might use this incorrectly. I want to use a .csv file that (as list) looks like: ...
1k views

### Generating random symmetric matrix

Suppose first that I want to generate a matrix whose elements are independent and identically distributed (i.i.d.) with distribution dist. This is easy: ...
227 views

### Why can't a string be formed by head String?

Since everything is an expression in Mathematica, why must a string object be formed by "abc" but not by a String[abc] ...
117 views

### Determining the range of parameters that yield real values for a certain NIntegrate form

I have specified just one set of $s$ and $g$ values that yields a real value for the NIntegrate below. It is possible that some $s,g$ combination can give rise to ...
155 views

### Why does LinearSolve return the transpose of the answer matrix?

I am trying to solve an equation of the form $dv=F\cdot dV$ where $dv$ and $dV$ are matrices derived from the row vectors $dx$, $dy$, $dz$ and $dX$, $dY$, $dZ$ respectively. If it helps, $F$ is the ...
213 views

### Solution of differential equation in terms of incomplete gamma function

I need help in solving equation 15 and 16 either manually or in Mathematica to get the solution in terms of the incomplete gamma function. This is what Mathematica tells me. I can't understand ...
341 views

### Any packages for vertex enumeration on Mathematica?

My work requires me to enumerate all vertices of a polytope defined by linear inequalities from time to time. And I'm mainly working with _Mathematica 9.0 on Mac OS X 10.9. So I wonder are there any ...
271 views

### Generalize WASD Function First Person Viewing

How might I generalize the following WASD question such that it works with any Graphics3D object and includes q and ...
740 views

### How would I input this truth table into Mathematica or Wolfram Alpha

I am unsure how to put the negations after a gate or before a gate?
263 views

### Accurately distort graphics

I would like to accurately distort this plot of $\sin(x^{1/2})$ (and others like it) so that the wavelengths are evened out (ie - "inverse-square root" it). I should like to do the same to "de-log" ...
314 views

### How to test for Indeterminate values?

I need something like this a = 101010/0; If[a == ComplexInfinity, True, False] But if I use ToString, I get what I want. ...
51 views

### How to pattern match an association? [duplicate]

I have the following: Clear[a, b]; a = {{1, 2, 3}, {4, 2, 5}, {6, 7, 8}}; b = GroupBy[a, #[[2]] &]; b whose output is: ...
177 views

### Change font of formula number in DisplayFormulaNumbered

I am trying to change the font of the formula number in a cell which has style DisplayFormulaNumbered. I can easily change the font of the formula I enter by selecting it and using the format menu. ...
102 views

### Compile issues, scoping and order of evaluation

I have a few questions about compiling functions, which I think are all related to scoping and order of evaluation. I will illustrate them by a minimal example of the problem I have. I'm sorry for ...