# All Questions

417 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. Ideally I'd be able to find the smallest value of $x_{n\nu}$ for $\exp(-kr\pi)$ close to 1, and ...
733 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 ...
187 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 ...
163 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 ...
297 views

### Data Table Manipulation

Suppose that I have the following ...
91 views

### SQL Queries with the Table function

Given the following connection to an SQL query works but the data comes out wrong: ...
200 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 ...
111 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 ...
74 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 ...
366 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 ...
452 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: ...
575 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; ...
473 views

98 views

### How to modify the file “KeyEventTranslations.tr” to use Enter to evaluate the current cell? [duplicate]

I asked the following question before, but I do not think it has been fully answered. By default, we use Shift+Enter to evaluate the current cell, and use Enter to get a new line. Is there a way ...
92 views

### Converting problem into form involving Probability

I want to solve the following problem symbolically, using Probability: What is the probability of the first random variate of a set to be present more than ...
111 views

### RSolve: Errors while solving Partial Difference Equation

I tried solving following partial difference equation in Mathematica by typing ...
602 views

### Convert list to sequence

I was just thinking how Tuples was created so , I came up with this, ...
169 views

### Performance on Multinomial Deviate is slow

Most of the time in my program is spent on this single line of code: out = RandomVariate[MultinomialDistribution[nt, tmp]]; ...
212 views

### Head of a MatrixForm expression?

An example in http://www-zeuthen.desy.de/theory/capp2005/Course/hahn/mathematica.pdf amounts to the following ...

15 30 50 per page