# All Questions

218 views

### Weighted Kirchhoff Matrix?

I have a weighted graph and I want its graph Laplacian matrix (what Mathematica calls the Kirchhoff matrix in the unweighted case). Is there an easy way to get this? For example, the command: ...
664 views

### Make good looking histograms from frequency data

I allways do my calculations in Mathematica and I make my histograms using ROOT language. However I am wondering is it possible to make good looking histogram inside Mathematica? A sample of what I ...
597 views

### Area of the largest rectangle bounded by $y=x^2$ and the x-axis within the unit interval

I am trying to find the area of the largest rectangle (whose sides are parallel to the coordinate axes) contained in the region bounded by the graphs of $y = 0, y = x^2,$ and $x = 1$ using ...
60 views

### Is SynchronousUpdating->False supposed to make this simple Dynamic example work?

x = 0; Dynamic[{x, Button["+1", Pause[6]; x++]}, SynchronousUpdating -> False] The documentation states that Dynamic and Manipulate will abort synchronous ...
193 views

### Strange result from evaluating a Limit expression

When I evaluate the limit of (1-Cos[x]) Sin[1/x] at x = 0 in Mathematica 9, I obtained ...
134 views

Assume that; ...
126 views

### Constrain plot points to below a certain line

I have a set of curves that take on large values when approaching 1. I'm trying to create a straight line with certain slope and then truncate the plot for any curve that goes above that line for any ...
161 views

Assume that ...
518 views

### WhenEvent in NDSolve

How come this doesn't work as I intended? ...
183 views

### FindMaximum inconsistency

The code below seems to work for n<11. But for n=11, and above, it outputs newa then just outputs "beep" sound. WhyTheBeep says "The kernel Local has quit ...
373 views

### How to guess initial complex value for FindRoot

I have to solve a transcendental equation for a parameter, say $\beta$. Now, the $\beta$ has a range from $ik$ to $k$ where $i$ is the usual imaginary root $\sqrt{-1}$ and $k$ is a real number. ...
827 views

### Specify a variable as an integer

I have a formula that always evaluates to a certain number for any variable X under one condition that X is an integer and ...
219 views

### Find white regions in image

At the white regions of this image I want to add a few random arrows. I would like to realize two different of adding the random arrows: The arrows may not leave the white region The arrows have to ...
811 views

### How do you configure Mathematica 9 to automatically evaluate all notebooks?

I have a Mathematica 6 course that I am using in Mathematica 9; there is no updated version. Every time I open a notebook I have to go to the Evaluation menu and click on "Evaluate Notebook". Is there ...
550 views

### Why does Integrate declare a convergent integral divergent?

When I try this command Integrate[1/Sqrt[(s^2 - u)^2 - 1], {s, m, Infinity}, Assumptions -> u > 2 && m > 10] Mathematica declares that the ...
562 views

### Export to CSV is very slow - can performance be improved?

I have to provide data exports from Mathematica to CSV format and it is very slow compared to other formats as can be seen in the following table: JSON, 15 sec, 8.4 MB TXT, 23 sec, 5.6 MB XLSX, ...
512 views

### Non commutative multiply- expand expression

I began to use Mathematica a few days. My problem is: How to expand expression like $(a+b)*(a+b)$, where this multiplication is non commutative? Mathematica can do this?
238 views

This is a follow-up question from linking the libraries for CUDALlink in Ubuntu 12.10. The tests that I execute (CUDAQ[], ...
61 views

### Finding Maximum Root [duplicate]

How can I find the greatest root for a polynomial if the polynomial degree is very large. One way is using NSolve. This command can find all roots in numeric. Then, ...
579 views

### How to collect terms with positive powers in polynomial

I am trying to collect all terms with non-negative powers of $x$ in polynomials like $\frac{1}{x^2}\left(a x^2+x^{\pi }+x+z\right)^2$ First expand the polynomial ...
111 views

### strange output from ToExpression

I want to set constraints to my parameters, e.g., "m", but Mma gives nonsensical output. How could I avoid this phenomenon by using another but "equivalent expression"? Or, is this just in my computer ...
218 views

### What ways are there to convert an Integer to a list of digits?

How can I convert an Integer to list of numbers? For example: 781049 ==> {7, 8, 1, 0, 4, 9} What are the possible ways of ...
166 views

### Calculating the rank of a huge sparse array

By virtue of the suggestion in my previous question, I constructed the sparse matrix whose size is $518400 \times 86400$, mostly filled with $0$ and $\pm 1$. Now I want to calculate its rank. Since ...
416 views

271 views

### DataRange problem in a ListLinePlot within a Manipulate

I'm trying to create a simulation of a set of lists with Manipulate[] and ListLinePlot[]. However, as my simulation starts with ...
66 views

### Restricting a plotted expression to reals in a Manipuate

I have an expression from which I'm trying to create a plot that I can manipulate. The expression contains Abs, and I only want to have it evaluated for reals. What ...
1k views

### Discrete FFT of non-periodic signal excited by short pulse

Say I have a signal F(t) which represents a excitation by a pulse (so it is not periodic and declining to zero amplitude). According to this answer, for instance, ...