2
votes
1answer
221 views

Rank functions of n by their order of growth

I'd like to rank some functions according to their order of growth (e.g. n^2 < n^3). I'm not sure how to do order of growth in mathematica, so I was trying to ...
2
votes
2answers
190 views

Replacing values above a threshold with 1 [duplicate]

I have a list with some values and I want to replace a value which is greater than 1 with 1 otherwise keep the value. In this case 10562: ...
1
vote
2answers
73 views

Unknown limit of an array of area integrals

Could someone explain why Mathematica can't finish computing this limit (this is a limit of an array, when n -> Infinity (n ...
7
votes
5answers
319 views

LengthWhile until first duplication

I have the need to trim each of a large number of potentially very long lists (10^6+ elements) to the length where the last occurrence of any distinct element happens, or said another way, where the ...
1
vote
1answer
62 views

How can we tell Series to treat the expansion parameter as an integer?

It is simple for Mathematica to find an asymptotic expansion for $\frac{1}{-1+p}$ as $p \rightarrow \infty$. However, if we want to restrict $p$ to be an integer and also include some terms that ...
2
votes
2answers
208 views

ContourPlot - plot only one connected component

How do I plot only one component in ContourPlot when specifying a height. For example, ...
0
votes
0answers
47 views

Differential curve geometry Frenet Formula [duplicate]

I am using Mathematica for differential geometry studies using Frenet Formulae. The problem is that I need to graph the solution curve r[t]. Suppose the curvature of a curve is k(s) = |s|and the ...
2
votes
1answer
225 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 ...
7
votes
2answers
250 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
52 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
123 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
84 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
102 views

Improper mutiple integral

I would like to solve the following integral: ...
2
votes
2answers
129 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 ...
2
votes
2answers
294 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
209 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
101 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
91 views

Constraining some rows from LeastSquares to lines

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

Transforming an image as an object

The problem is following: I have a following animation: ...
0
votes
2answers
108 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
52 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, ...
2
votes
1answer
34 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
26 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
134 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
72 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
52 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
83 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
114 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
236 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
324 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
94 views

Animated matrix 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. Ive tried the following but when I open it up it only does the first two matrices, I have 10 ...
2
votes
2answers
131 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 ...
0
votes
0answers
74 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
98 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 ...
0
votes
0answers
78 views

Cannot calculate an integral

I am new to Mathematica. So I just run a basic procedure but Mathematica didn't calculate this integral. Maybe it is too complicated to be done. ...
2
votes
0answers
81 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
138 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 ...
6
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
182 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
114 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
277 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
200 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
189 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
104 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 ...
0
votes
0answers
60 views

Numerically solving a PDE with dependance on a fixed grid point

I am trying to solve partial differential equations of the type $y^{(1,0)}(t,x) = f(y^{(0,1)}(t,x), y(t,x_0))$ where $x_0$ is a fixed point. For example, when pluging this into Mathematica : ...
3
votes
2answers
161 views

Why is my compiled function slower than a regular function?

I have the following functions: ...
4
votes
1answer
89 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
93 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
158 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: ...

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