# All Questions

321 views

### Laplacian or Grad of an InterpolatingFunction

For obtaining a Schlieren image from an equation for density, I need to calculate the first derivative of density and make a contour plot. The below code snippet calculates the first derivative w.r.t ...
397 views

### Inconsistent initial and boundary conditions

I have a 4th order nonlinear PDE with the following BCs and IC: ...
277 views

### Borked Find Window in OS X

I've been having this happen to me on a daily basis with the Find & Replace window on OS X: No text can be typed into the red regions, so all find & replace functionality is gone when this ...
598 views

### Problem with Union and Intersection

Consider the following: list={{a,b,c},{c,d,e},{d,e,f},...{x_,y_,z_}}; I would like to apply Union on the elements of the list ...
394 views

### Cannot evaluate differential in Mathematica

I have a small toy script in Mathematica that I am trying to use to evaluate the pdf of $Y$ where $Y=X^2$, and $X$ is uniformly distributed in $[0,a]$. The script is, ...
173 views

### Delete a style type from stylesheet

I have created a new stylesheet but now I'd like to delete a style type, for example "program" from it. How can I do it ?
426 views

### How to impose custom style to the edges of a graph

We construct a graph as the following. ...
3k views

### Product of elements within a list

Please Consider : list={{5,2,6},{2,8,3}} I need to get the product of all the element within list : As of now I do this : ...
91 views

### Replacing more than one element from a Sublist

The following expression allows me to extract the value of x and y: ...
44 views

### Numerically Integrating to find a Maximum using NDSolve

I am trying to numerically find an equilibrium (maximum) of a function using its differential. The following is a simplified version. ...
121 views

### GUI of a Karnaugh Map

I intend to implement a three-variables Karnaugh map with the following code. There are two points I failed to figure out. How to remove the outer double-line border? How to change the toggling into ...
76 views

### Use NDSolve to solve a PDE

I have the following PDE (a master equation, and $P$ is probability density, $0\le x\le1$ and $0\le y\le1$): $$\partial_t P(x,y,t)=x\partial_xP(x,y,t)+(1-y)\partial_yP(x,y,t)+2P(x,y,t)$$ The ...
66 views

### How to limit only two “0 and 1” strings for an xor implement?

I tried to implement some logic gates for a series of "0 & 1" strings, just like and, or, nand, nor and not listed below. How could I limit xor only accept a two strings list as its argument? ...
48 views

### plotting 3d points: z-axis is squashed

I am plotting 3D points and it occurs to me that Mathematica doesn't have an easy way to specify my points to be plotted in a uniformly scaled cartesian space. For example I plotted ...
93 views

### Factoring terms out of a polynomial

I don't do much algebra in Mathematica and was surprised to discover, while attempting to answer this question, that I had no idea how to factor out an expression from a polynomial. The question was, ...
103 views

### Find all roots in the interval of nonlinear equation

I am struggling on how to find all the roots of 1+1/2^x+1/3^x==0 which lie in a given of real and imaginary interval. Solve ...
96 views

### Looking for an elegant way to solve a (system of) ODEs/functional equations with undetermined coefficients

I want to solve an ODE using undetermined coefficients/guess-and-verify and am looking for an elegant way to use this technique. I am running into a few ugly warts. Here is a basic implementation for ...
175 views

### More efficient implementation for comparing coefficient lists in a Do-loop

I'm wondering how to speed up the following code so it actually computes for $n=2$: ...
176 views

### Marking specific points on a 3D curve

Here is the curve below. (written as a position vector) r = {Cos[7 Pi*t], Cos[6.2*Pi*t], 2.5*t} ParametricPlot3D[r, {t, 0, 2}] I want to know how I can mark ...
150 views

### On Parameter Estimation using FindDistributionParameters

I am a novice of Mathematica and have recently started my self-study of maximum likelihood estimation (MLE) using Mathematica. I would like to estimate the parameters associated with a distribution ...
82 views

### Plot a vector valued function of two variables using color density

I have a vector (3D) valued function of two variables. I want to visualize it as a density plot, using R,G,B color values to display the value at the point (x,y). I've come up with a couple of ...