2
votes
2answers
221 views

ContourPlot - plot only one connected component

How do I plot only one component in ContourPlot when specifying a height. For example, ...
2
votes
1answer
399 views

Parallel evaluation and memory use

I have never used Mathematica's parallel evaluation before and have some trouble getting it to work properly. For the record, I am running Mathematica 9 on Linux with an Intel Core i7 processor (4 ...
8
votes
2answers
310 views

Why do I get a different value when I change the order of integration?

I think the following two-dimensional integrals should be equal, since they both integrate the function over the half plane defined by $t>\tau$. $$\int_{-\infty}^\infty \mathrm{d}t ...
0
votes
1answer
58 views

Function output of two lists are only diagonal elements

I'm having a little crysis over here. What I basically want to do is some sort of 3D-Plot, but I'm only interested in the resulting values. I have two vectors x and p: ...
6
votes
1answer
193 views

Better way to get Fisher Exact?

I want to perform a Pearson's $\chi^2$ test to analyse contingency tables; but because I have small numbers, it is recommended to perform instead what is called a Fisher's Exact Test. This requires ...
1
vote
1answer
93 views

Experiment with TagSetDelayed involving Part

Reading Associating Definitions With Different Symbols, I was intrigued by this: You can think of upvalues as a way to implement certain aspects of object-oriented programming. A symbol like ...
1
vote
1answer
118 views

Improper mutiple integral

I would like to solve the following integral: ...
4
votes
2answers
149 views

FactorInteger over UFDs

How can I factor 'integers' over other quadratic number fields (not just gaussian integers). For instance, how could I factor $7 = (3 + ω)(2 − ω)$ over Eisenstein integers ($ω = \frac{-1+ I ...
3
votes
2answers
569 views

Add Point to Plot3D

I'd like to simply add a nice thick point in $(0,0,0)$ to Plot3D[(y^2/x), {x, -3, 3}, {y, -3, 3}]. The solutions I came across to add anything to ...
0
votes
1answer
304 views

How to manipulate some list-plot in Mathematica

I have two separated matrices in the form X[[i*dx,j*dt]] and V[[i*dx,j*dt]] where i & j are integers from (1 to N) & (1 to M). V & X are velocity ...
1
vote
1answer
120 views

OpenSQLConnection error

I used to be able to connect to a SQL Server database. I haven't run this program for a few months. I tried it today and it failed, so I went back to try OpenSQLConnection[] and got the following ...
0
votes
1answer
94 views

Constraining some rows from LeastSquares to lines

For two matrices, A and B, with dimensions {n,p} and ...
0
votes
1answer
249 views

Using an image as a moving object in an animation

I have following animation: ...
0
votes
2answers
140 views

Define a function on a parameter argument set to zero

Say I have an expression (matrix) that depends on several variables. f= {{a, b+c},{2a-b^2,c^5+a b}} I want to define new matrices with the single parameter ...
0
votes
1answer
61 views

How to ignore terms containing in the summation of multiplications

n=4;L=3; p0[n_Integer]:= Product[ Sum[Subscript[r, k][l, l], {l, L - 1}], {k, n}] // Expand; How to ignore terms containing three or more multiplications of [2, ...
3
votes
1answer
49 views

Table doesn't replace inside conditionals (If, Which) [duplicate]

This: Table[If[cond, y], {y, 1, 3}] outputs this: {If[cond, y], If[cond, y], If[cond, y]} The ...
1
vote
0answers
28 views

custom precedence for custom infix operator with InfixNotation [duplicate]

I am trying to define several custom operators with custom precedence to implement geometric algebra. Loading the notation package << Notation` I can ...
1
vote
3answers
139 views

More elegant/efficient solution to browse through an array

I have an array of lists and want to correlate every list with each other like this: ...
1
vote
0answers
96 views

Load a Mathematica Notebook using .Net code

I have gotten a tremendous amount of information from the question posted at (Load a Mathematica Package via .Net code), which my application is very similar to. Specifically in that thread, the ...
0
votes
0answers
62 views

DSolve cannot solve for certain branches of the solution help pls

I get an error message while trying to compute this code.. help pls ...
3
votes
0answers
113 views

random Poisson process over multiple variables (state vector) for chemical kinetics

Has anyone figured out how to coerce ContinuousMarkovProcess to work with a state vector, transition matrix, and rate (propensity) vector, and RandomFunction to return pairs of state vector and time, ...
1
vote
1answer
138 views

How to obtain the number of Markov Chain transitions in a simulation?

I would like to obtain the number of transitions from each state in a Markov Chain simulation to other states, including back to itself so I can compare the simulation results to the transition ...
4
votes
1answer
335 views

ContourPlot3D using a Matlab function through MATLink

I have a Matlab function which accepts a 3 dimensional vector and returns a single number. I want to use this through MATLink to make a 3d plot. A unit sphere: ...
5
votes
5answers
338 views

Isolating characters in a string

I'm struggling to find the right function in mathematica to isolate specific characters in a string. I have got a formula as string (I imported it from an excelfile) like this: y = 0.97*x1 + ...
4
votes
1answer
151 views

Exported animated gif with matrices will not work?

I want to export a list of matrices as a gif so that they will appear one after another 2 seconds apart. I've tried the following but when I open it up it only does the first two matrices and I have ...
2
votes
2answers
174 views

BarChart3D does not print zeros and odd tick positions

Note: This is a version 9.0.0 problem that is fixed in 9.0.1. I want to generate a simple 3D view of some frequencies for two variables. I have the counts in a 4x3 matrix, say. This is my bar chart ...
1
vote
1answer
113 views

Find Numerical Derivatives (With Errors) given some data

I have a question. Suposse I have some data with their respective errors: ...
3
votes
1answer
113 views

Setting label in DendrogramPlot

I want to create a dendrogram with the labels being a visual representation of the data. Something like this: How can I do that in Mathematica? My attempt so far hasn't been very successful. The ...
2
votes
0answers
82 views

Is there a function similar to SQL's Iserror? [duplicate]

I have an output which I want to hide if there is an error otherwise display it. The output is a Dynamic[output] so I can't simply use something like ...
4
votes
1answer
163 views

Animation of tube with fixed height

the problem is following: my task is to make an animation: tube changes its radius but doesn't change its height. With command ...
8
votes
7answers
1k views

How to select all elements above the main diagonal of matrix?

How to select all elements above the main diagonal of matrix? I need to create a list of them.
0
votes
1answer
321 views

Symbolic matrix simplification and solving

I am trying to expand or solve an equation that contains matrices for a certain matrix, but it is not working: ...
2
votes
2answers
128 views

Elegant way to rearrange year/date table into time series/values

I often have data in the form of YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 1950 -1.022 -1.146 -1.289 -1.058 -1.419 -1.36 -1.334 -1.05 -0.578 -0.395 -1.151 -1.248 1951 ...
3
votes
1answer
417 views

How do you use fourier transforms to perform a deconvolution

I've been trying to teach myself about deconvolution through fourier transforms, but I seem to be missing something simple, as my results are garbage. I start by defining a test function and a window ...
-5
votes
1answer
313 views

How can I plot a function that is the sum of another function?

I plotted m[t], but actually what I want to plot is g[t], which is a summation of m[t] from ...
-1
votes
1answer
353 views

Mathematica Semilog (LogLinearPlot) using x,y points from table [duplicate]

I am trying to use the LogLinearPlot in Mathematica 9 to create an x-axis only logarithmic plot that looks like this (Based on N^1.85 graphing paper) http://pingfire.com/ What it does is model a ...
0
votes
1answer
113 views

How to return the points {Xi,Zi} generated by ContourPlot [duplicate]

I have the following two questions How to visualize the dependence Y versus X with Mathematica using ContourPlot, if it is given by the following system of two equations: Y=f(X,Z) and g(X,Z)=0 ...
3
votes
2answers
198 views

Why is my compiled function slower than a regular function?

I have the following functions: ...
4
votes
1answer
102 views

Parallelize[Mapindexed[]], level={-1}? Sal Mangano's 《Cookbook》

It is easy to Parallelize[] Map[] & MapIndexed[], as having been shown in MMA9 Help for ParallelMap[] and Parallelize[]. For MapIndexed[], the default levelspec is {1}. However there are many ...
0
votes
0answers
116 views

Iteration of multiple functions that feed into each other

I'm trying to figure out how to iterate through several functions that all "feed" into one-another but am having some trouble. Here are the variables: ...
2
votes
2answers
170 views

How can I thread lists of different sizes?

What I need is the equivalent of Maple's zip(+, A, B, 0). Sure I can get it with: ...
1
vote
2answers
93 views

Grouping constants in expressions

Starting from the general expression: i A(a x + b y + c z + ...) + j B(a' x + b' y + c' z + ...) + k C(a'' x +b'' y + c'' z + ...) I'd like to rearrange it to ...
0
votes
1answer
124 views
3
votes
1answer
202 views

Background in ItemStyle

I would expect the following to output the same grids ...
1
vote
1answer
221 views

Looping with NDSolve?

I have a series of PDE equations that are solved with NDSolve for certain variables $a$ and $b$ - Now, I want to see the output at a time $t$ as $a$ and $b$ change; so I was thinking of a loop ...
7
votes
1answer
432 views

Estimation of vector autoregressive (VAR) process

To estimate 1-dimensional VAR process (which is AR process) you can easily use functions EstimatedProcess or ...
0
votes
0answers
37 views

Varying number of function arguments [duplicate]

I have a function of six arguments: ffit[q1_, q2_, q3_, q4_, q5_, q6_] := (a1*q1^2 + a2*q2^2 + a3*q3^2 + a4*q4^2 + a5*q5^2 + a6*q6^2) ...
7
votes
3answers
161 views

Checking through an expression

I am writing a code that manipulates expressions that contains functions with an arbitrary number of arguments. An example expression is ...
1
vote
2answers
133 views

Rate of change of dynamic variable

I have made a program that goes like this, the goal is to estimate the remaining time of a function (it is running a bunch of solveChase[] functions with different parameters which can be seen in the ...

15 30 50 per page