# All Questions

190 views

### setting real parameters in Hamiltonian matrix

The following Matrix represents my Hamiltonian. m = {{ B/2 - d - j/2 + a, (Sqrt[2]*j)/2, M}, {(Sqrt[2]*j)/2, B/2 + a, 0}, {M, 0, (-3*B)/2 - d + j/2 + a} How can ...
134 views

### Choosing the units for plotting

I´m new to using units in Mathematica. I have read other similar posts about this issue but I haven´t found an answer so far. My problem is simple: I want to plot a certain function with a certain ...
522 views

### How to substitute the following conditions into an expression?

I have an expression: $p=a\;b\; x + b^2\; y + a\;c\; z$. I want to substitute $a\;b=1$, $b^2 = 2$ and $a\;c = 4$ to obtain $p = x + 2y + 4z$. How can I tell Mathematica to do that? I dont know how to ...
937 views

### How to optimally solve and generalize this Conway's Game of Life puzzle

I tried solving this using mma. I am aware of this command - Cellular automata. But i don't want to use that coz then there is no challenge. So below is how i did it and my question is can this be ...
193 views

### Launching Remote Kernels takes a lot of time

I recently played around with establishing a remote kernel setup without using mathematica grid. To do this I use the LaunchKernels[] command and ...
93 views

### When and why are Assuming and Assumptions not equivalent? [duplicate]

In this question there's an example of an integral where using Assuming and Assumptions give different results: ...
409 views

### Get Coordinates 4 significant digits limitation

The tool "get coordinates" (clicking on a plot), seems to work with a fixed number of significant digits (4), in a way that we can quickly lose sensibility (the tool really becomes useless). The ...
209 views

### Simplification of integrals depending on a parameter [duplicate]

Assuming[Element[n, Integers], Integrate[Sin[x]*Sin[n*x],{x,0,Pi}]] returns 0, which is obviously wrong for n=1. ...
653 views

### Double integral with variable in the limits

I'm trying to solve this integral:  ...
435 views

### How to Merge Date and Time?

Given the following time series data where row is date and column is time intervals. ...
542 views

### Defining Piecewise Functions [duplicate]

I'm having trouble defining piecewise functions. What I have so far is a function that outputs something in a suitable format for Piecewise: ...
103 views

### List of lengths of runs of elements

I have a list where a few distinct numbers occur, e.g. {41, 41, 41, 1009, 41, 41, 41, 41, 41, 41, 41, 1009, 41, 41, 41} I want to extract the information of how ...
301 views

### listplot very large numbers

Suppose we have the following function: NN = 150; W[n1_] := NN!/(n1 ! (NN - n1!)) (1/2)^n1 (1/2)^(NN - n1) Then we can Plot or Listplot it: ...
369 views

### How to plot a function with two parameters determined by another parameter?

I have one small question. My code is like follows. ...
99 views

### How do I plot a variable against another variable in Mathematica?

I'm working on a system that has molecular interactions, for which I have the defined constants. r=0.5; a=1; c=0.01; d=0.1; e=0.02; k=500; and my system of ...
824 views

### Rolling Ball Image Background Subtraction [closed]

I am currently doing particle detection on some images and I wanted to do an Image Background Subtraction similar to what is available on ImageJ so as to even out the background tone. ImageJ uses a ...
524 views

### Numerical Integration with Variable Parameters

So I want to numerically compute the integral of a long complicated expression over a specified domain (in this case an ellipse). I know how to use a Boole function to sample within the ellipse, but I ...
52 views

### Generating Suffixes [duplicate]

I am doing a large Matrix calculation in which I need to generate symbols first like $F^{\mu\nu}$ I would like to get $\mu\nu = 00, 11, 22, 33$ and so on. I need to have the symbols before I can ...
1k views

### Import Large Excel File

Currently, I am working on a large time series dataset, which contains 928,586 rows and 35 time intervals in columns, in excel format (.xlsx) and using Import to ...
71 views

### Palette created by my code doesn't work

I think I am lost on some basic issue ... I created two CellTags, tagone and tagtwo If I create this palette inputting the following code by hand I get a beautifully working palette that makes me ...
64 views

### Mysterious behavior of Precision for complex arrays

Mysterious behavior of Precision: {{1.0+I*0.0},{0.0+I*0.0}} // SetPrecision[#,30]& // Precision // Print; ...
311 views

### Domain errors with Maximize/NMaximize

I am trying to maximize a (somewhat) complicated function over probability distribution $p$ and $q$. Here is my input: ...
165 views

### Generating list of coordinates in $\mathbb{Z}^n$ given by set of inequalities

I am trying to generate list of coordinates that forms a subset in the integer lattice $\mathbb{Z}^n$. This set is given by set of inequalities. Right now, I am using the following: ...
61 views

### How to change the position of numbers on plot [duplicate]

How to change the position of numbers in axes on plot? I want to see the numbers on the x-axis over it, not under it as it is now to have them clearly visible.
191 views

### How do I prevent exponents from being expanded when displaying text

I have a power of 2 in a list, and I want it to show as $2^{31}$ (2 with exponent 31), not 2147483648. I've tried this: ...
271 views

### Cannot get specific value from NDSolve (multiple functions)

I am trying to solve six connected differential equations. This is my code: ...
40 views

### Using Manipulate, how do you display the points on the curve and the tangent vector? [duplicate]

I'm new to Mathematica and my assignment is very vague... I'm hoping someone can explain to me a bit more of that this quesion means: Given the curve C, display the point on the curve and the ...
325 views

### How to get a solution for the following equation?

When I try to solve this equation using Mathematica: Solve[Exp[b*x]-c*(x^2)-a*x-1 == 0, x] /. {a -> 6.336, b -> 8, c -> 32} I don't get any result and ...
172 views

### Why won't Mathematica plot my function? [duplicate]

I'm using a theoretical answer found on the official Wolfram site as a reference to ensure my code isn't faulty (even though I'm fairly confident that my original code is half decent). ...
1k views

### Is it possible to calculate a Lebesgue integral in Mathematica?

As the title says, I wonder if it is possible to calculate a Lebesgue integral in Mathematica, especially when the domain of integration is $\mathbb{R}^N$, or in other words multivatiate Lebesgue ...
166 views

### Reading many single files and creating numbered (? or indexed) variable

I tried many different approaches, but I could not solve the following problems, I appreciate your help: What is the best way to read many data files? I mean we have ...
197 views

### Avoiding overcomplicated structure of groups, masks and splited text on vector format plot export

I'm trying to generate a template for exporting figures and plots in a consistent way that will allow easy editing in any vector based drawing software (such as illustrator). My problem is that ...
87 views

### How can I terminate a running computation in Manipulate?

I want to make a simple cdf file that makes some hard computations inside Manipulate. Is there a simple way, lets say using a "stop!" Button, to terminate the time consuming calculations--without ...
147 views

### Problem with With [duplicate]

I am puzzled byWith. it does not seem to work. Please see example below (I have also used Evaluate and ...
156 views

### Bare symbol invocation fails but not if used with an argument

How to achieve the following behavior on a symbol f? Background: The main goal is to use the symbol to tag an abstract data structure where downvalues are used to store information. Only defined ...
332 views

### Need help with solving a second order differential equation

I need help with solving this differential equation. ...
131 views

### Maximization of a function within a unit square [closed]

I work in a unit square. I have some conditions under which areas within the unit square are defined. Say for simplicity that there are two conditions which define two areas. For example, if y > 1/2 ...
70 views

### Properly applying BandstopFilter

In the documentation about BandstopFilter it says that the cutoff-frequencies w1 and w2 in ...
62 views

### Specifying Table/grid dimensions in version 7

The result of my calculations is quite large list (nested list to be precise). I would like to improve its visualization, to make it more legible, by setting the number of columns to let's say 5. ...
89 views

### How to increase range in Plot without exceeding maximum bounds?

Does there exist some way to increase the plot range of following plot from 10^7 to new value 10^16? It exceeds its maximum ...
174 views

### Dynamic generation of Buttons

The Project I am trying to dynamically turn on/off the display of data for a circos-esque plot that I generated. The Code I have data stored in mfData and a ...
245 views

### Using Mathematica to Solve for Electric Field from finite cylinder

For a cylinder that is of length L and radius s and possesses a charge distribution of sigma across only the cylinder part and not the endcaps, I am trying to calculate the Electric-field. The ...
170 views

### How can I improve Do loop?

I have very large input of time series data (over 30000 observations) that look like as follows: ...
1k views

### Mathematica EPS graphics and psfrag in $\LaTeX$

I used to to use MathPSFrag in Mathematica to export graphics to EPS for inclusion in $\LaTeX$ files. However, with recent versions of Mathematica this does not seem to work very well anymore, see ...
160 views

### Solve equations for all values of variables, rejecting certain types of solution

I have an expression, expr, containing 3 variables, 4 coefficients and 2 non-zero generic constants. I want to solve for the 4 coefficients such that the equation ...
729 views

### Can someone help me solve this x*y*z=180

I have one question I've been trying for a while but I can't get the result for my equation.. So I've been trying hard but I can calculate only by hand but the problem is that I am afraid to miss any ...
170 views

### Why Eigenvalues thinks matrices are non-numerical

I use Mathematica version 9.0.1. ...
217 views

### Discretizing data using quantiles in Mathematica

I am trying to discretize a long array of real numbers into a uniformly distributed integer array. To do this I am identifying the quantile where each real value sits and writing it out to the output ...