# All Questions

93 views

### Setting CheckboxBar defaults under Manipulate

How is the default for the checkboxes created by CheckboxBar in a Manipulate set to be checked instead of unchecked? (The ...
118 views

### Error Trapping Complex Infinity Error due to Divide by Zero in Manipulate

I want to use a Manipulate that has two controllers that end up as a difference in the denominator of an expression. It is easy enough to set up the initial ...
73 views

### Moving the start of a graph to the right, finding maxima in an oscillator

I have the following code written to simulate a driven damped oscillator ...
70 views

### How to compile gather [duplicate]

First question，How to Compile this？ gather[data_]:=Gather[data, Mod[#1, 3] == Mod[#2, 3] &] I dont know why this is wrong. ...
349 views

### Trying to solve a transcendental equation involving bessel functions

I've never used Mathematica before and am trying to numerically solve equation (12) from this paper: http://arxiv.org/abs/hep-ph/9907218v2. Ideally I'd be able to find the smallest value of $x_{n\nu}$ ...
647 views

### How to make a curve selectable from a scaned image and convert it to a list of coordinates

I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ...
175 views

### Set PointSize to pixel size

I have a set of 1million 2D points and I would like to produce an image 200x200 pixels where each point will have the size of a pixel (no more). Additionally each point may repeats several times so I ...
107 views

### What are the hidden specifications for FindRoot

The Help page of FindRoot says: "by default, FindRoot uses Newton's method (Newton-Raphson) to solve a nonlinear system" (or a nonlinear equation I ...
281 views

### Data Table Manipulation

Suppose that I have the following ...
89 views

### SQL Queries with the Table function

Given the following connection to an SQL query works but the data comes out wrong: ...
95 views

### How do I apply a rule to every element in a matrix? [closed]

I need to apply a set of rules (I used Which) to every element in a matrix, but the rules are dependent on the position [[i, j]] ...
175 views

### FindRoot constrained to maximum

I am using FindRoot to find the local maximum op some function, by examining where its derivative is zero. However, keeping the starting value the same, sometimes ...
103 views

### Accessing Draw Tools objects with notebook commands

In a notebook I would like to be able to access and modify the properties of draw tools objects after I've drawn them on a graph by hand. For example, if make a plot and, with draw tools, make a ...
16 views

### ?AspectRatio? setting to obtain equal length pr pixel on all axes [duplicate]

Like these does: Show[Graphics[Rectangle[{2, 1}, {15, 2}]]] ParametricPlot[{t,t t},{t,0,2}] how do I create a Plot[] with ...
72 views

### Mathematica exit when calling plot. Bug?

I'm currently studing the behaviour of some integral for which I cant find an analytic solution. As this function depend on a vector on the unit sphere, I first defined it with 3 parameters before ...
233 views

### How to use the function ImageCorrelate? [closed]

I am a beginner in using Mathematica, know little about optics. However, I would like to know how to understand the function ImageCorrelate, since the ...
305 views

### Why does Mathematice dislike my boundary condition in NDSolve?

im trying to solve a PDE-System, with the "periodic boundary condition" c[t,0]==4*c[t,2pi] But mathenmatica says: NDSolve::bcedge: "Boundary condition ...
422 views

### Mathematica style (drawing cubes)

I wanted to draw (lattice-aligned) unit cubes inside a sphere with a given radius centered on the origin, so I wrote this program: ...
507 views

### Solving simultaneous exponential equations

In[1]: Solve[{(1 + k)^n == 0.6, (1 + k)^(n + 1) == 0.3}, {n, k}] Solve::ifun: Inverse functions are being used by Solve, so some solutions may not be found; ...
426 views

63 views

### inverting this equation [closed]

I'm trying to inverse this equation Z = X + X^2 / 2 but couldn't wrap up my head around it. If anyone can provide a step by step solution to this it will be ...
397 views

### ReadList with header and foot lines

I want to do some large data analysis, and i want to be able to import files in a fast way. I tried Import, but it is quite slow; ReadList takes half the time. This is the code I was using: ...
403 views

### Compile function which calls other functions to C

I have a function which calls other functions and I would like to compile it to C code. For example: ...