1
vote
5answers
134 views

What's wrong with my implementation of SquareFreeQ?

This was a question I had last month: Part A: Looking at the exponent of each of the elements in the list, FactorInteger and using ...
1
vote
1answer
289 views

Plot the solution complex transcendental equation

I'm trying to plot an implicit function satisfying a complex transcendental equation. The code is the following: ...
1
vote
1answer
70 views

What's wrong with the following Plot in Manipulate?

I try to show the convolution of a step function and a triangle function is smooth with the following code: ...
3
votes
2answers
515 views

Interpolating data with a step

Suppose I have some data with a step in it: data = {{1, 1}, {2, 2}, {3, 3}, {3, 4}, {4, 5}, {5, 6}}; Interpolation will complain about this and not give you an ...
5
votes
2answers
165 views

BezierCurve in EdgeShapeFunction fails when used on multiedges graph

I would like to create a network graph with curved edges. To do this, I wrote this function: ...
1
vote
1answer
247 views

Formatting plot of symmetric points differently to asymmetric points

From an array of numbers, I would like to determine (and then colour appropriately) which points are symmetric about a given axis (here, $x = 1/2$), and which are not. For example, form this: ...
2
votes
1answer
231 views

How I can make a menu with different graphs with modifiable parameters?

I want a user friendly window in which to have a menu where you can choose the chart you want to display, in which you can move parameters in order to note the width or height of the chart, but I try ...
3
votes
3answers
1k views

Convert Integer to Real

Is there a preferred way of converting an Integer to a Real? What I'm using at the moment is ...
0
votes
1answer
154 views

NDSolve finding solution when it shouldn't

NDSolve in mathematica drives me crazy and I'm seriously thinking about switching to Matlab because of strange bugs I run into. ...
1
vote
1answer
118 views

How to use ProbabilityDistribution for a posterior expression [duplicate]

I am performing a Bayesian updating on a Lognormal prior. After combining the prior and likelihood and dividing by the normalization constant I get the following expression as the posterior: ...
2
votes
1answer
86 views

Plot with non-standard domain

I have data {x, y} where x starts at -25 degrees and goes up to +25 degrees in 1 degree steps, and then comes back down to -25 degrees in 1 degree steps again. I ...
2
votes
1answer
647 views

Newton-Raphson Method and the Van der Waal Equation Coding question

So I need to find Specific Volumes using the Newton Method from the Van der Waal equation over a change of constant Temperature but variant Pressure. I have been able to make a list of however many ...
2
votes
2answers
139 views

How to plot complex values given by Solve

Update Solve[N[Table[BernoulliB[n, z], {n, 10, 10}] == 0]] ...
2
votes
2answers
146 views

bulk initialization of associative array/hash implemented with function pattern matching?

I see that we can do associative arrays in Mathematica using functions that have implicit pattern arguments, as in ...
0
votes
1answer
187 views

Adding labels on ArrayPlot and coloring rows

I need to add lables on the right from ArrayPlot for each row and color the black square of each row depending on values from two list. Color list has a numbers in some range and should be mapped ...
0
votes
0answers
38 views

Use Output as Input [duplicate]

I have this function which as a result returns a point ...
11
votes
1answer
230 views

Why is `D[a[b][c],a[b]]` equal to `1[c]`?

Background: I had the same issue as described here, and I went to extend Mr.Wizard’s code such that a[b][c] would be shown as $a_b^c$. Issue: To my surprise, ...
12
votes
4answers
527 views

How do you get a list of filenames from a URL?

How would I get a list of filenames available at a URL? For example, list the files at: http://www1.ncdc.noaa.gov/pub/data/cmb/drought/weekly-palmers/2005/
0
votes
0answers
44 views

How to fit ODE's coefficient, just like using NMinimize [duplicate]

I want to fit ODE's coefficients to a model. I tried using NMinimize, but it seems it does symbolic instead of numerical calculations. ...
4
votes
3answers
790 views

Connect to remote Ms-sql Database

I can connect to the local Database(installed in my system) from Mathematica via ...
6
votes
3answers
395 views

Flow in pipeline graph

I have pipeline directed graph which has one source and several sinks ...
3
votes
3answers
210 views

What is the formula for this numerical series?

I'm developing a questions game. My goal is that the score for each correct answer will increase as the user answers more questions. Initially there are 15 points for each correct answer. Every 4 ...
2
votes
2answers
160 views

How to increase the size of the dot produced by OverDot[]

As the title says, I want to find a way to increase the size of the dot produced by OverDot[]. Here is a simple code ...
58
votes
1answer
2k views

Profiling from Mathematica

I've always wished I could do some profiling like you get in Wolfram Workbench, but directly from Mathematica, without using or having Workbench. If it is possible, how can I do it?
5
votes
2answers
483 views

10bits per rgb / 1024 shades of gray?

Can we display 10 bits per rgb in Mathematica? I'm using a quadro card and 30 bit monitor and can get a smooth gradient using Psychtoolbox in matlab. The following Mathematica should produce a bar ...
3
votes
2answers
187 views

Differentiating a Cumulative Distribution Function which has a discontinuity at $0$

I want to take the derivative of a distribution function which has a discontinuity at $0$. Here is the function: ...
1
vote
0answers
164 views

Compute coefficient of Generating function

Given a generating function $F(z)$, is there any way to compute the coefficient $a_k$ of $z^k$ by Mathematica? One method is to calculate by the equation $\frac{F^{(k)}(0)}{k!}$. However, this ...
10
votes
2answers
734 views

Derivative from the left and right

I am currently trying to write a script that takes a curve $C$, a starting point $p$ and a direction vector $\vec{v}$ and calculates the path of a beam starting at $p$ in direction $\vec{v}$ when it ...
1
vote
1answer
136 views

Assumptions in mathematica when Symplify on Log[Exp[a/b]]

In mathematica 9.0: This: Assuming[b > 0 || b < 0, Simplify[Log[Exp[a/b]]]] yields: a/b However, this: ...
4
votes
1answer
263 views

Compatibility issues for Combinatorica package

I am trying to use the Combinatorica package in a Mathematica version 9 in the following code : ...
4
votes
1answer
249 views

MapThread Alternatives

I want to add two matrices, the first one containing a 2D vector at each position the other one a list of 2D vectors. The 2D vector from the first matrix should be added to each of the 2D vectors at ...
6
votes
3answers
961 views

Customizing & finding intersection points in polar plot

I want to verify a theory stating that a golden mean spiral plotted on a polar graph will have intersection points at specific values. There should be 8 concentric circles, each at the same ...
3
votes
1answer
252 views

Extract date from a not well-formed string

Is there a way to robustly extract date and time from a text? Say for example: ...The event will be held on 17/10/2013 at 3:30 PM in the room 121 and everyone is welcome... should return: ...
1
vote
0answers
57 views

Parallelizing an associative binary operation

I have an associative binary operation '.', which I often use in this sort of way: result = expr1 . expr2 . expr3 . expr4 The ...
2
votes
1answer
185 views

Plotting Laplace's equation on an infinite domain

I am trying to plot my solution to a Laplace equation on an infinite domain. However, when I try to plot it, Mathematica just runs with nothing happening. ...
4
votes
3answers
202 views

Simplifying expression with patterns (Replace)

Q1: I need to simplify some algebraic expression, according to particular pattern, namely: \begin{equation*} x^m = \left\{ \begin{array}{ll} 1 & \text{if } m \text{ is even} \\ x & \text{if ...
0
votes
1answer
137 views

Histogram For Non-Numerical Data

I have a non-numerical data, let say data = Table[RandomChoice[{0.2, 0.3, 0.25, 0.15, 0.1} -> {"A", "B", "C", "D", "E"}], {500}]; and i want to make a ...
8
votes
2answers
303 views

Organise a graph's vertices into levels

I would like to organise a graph's vertices in levels. Consider ...
9
votes
0answers
91 views

How to capture implicit fails in Plot or Show? [duplicate]

How can I make a construct similar to C++ functions: try{} catch{} I want to use it to avoid showing a lot of errors in the plot area when for example one of the ...
11
votes
9answers
4k views

How do I extract a number from a string?

I want to extract the number from an alphanumeric string. This is what I tried: StringTake["thiru3", {6, 6}] The result I got is ...
0
votes
1answer
88 views

Whitespace after number subscript

When I write something like this: (Subscript[x, 0], f(Subscript[x, 0])) I get some undesirable whitespace after each of the ...
3
votes
1answer
829 views

How to find an asymptote of a logarithmic curve

An exponential decay curve has been plotted asymptoting at approximately x=30 (correct for what I am looking at) How can I find the exact value from the curve? I was hoping to be able to use ...
4
votes
1answer
114 views

Memory usage of timeseries - lists of {Integer32, Real32}

A list of {Integer32, Real32} items in Mathematica seems to use 12-times as much memory than the C equivalent array of structs. ...
3
votes
1answer
205 views

Plot Ticks disappear when combining Plot with Graphics

I'm attempting a simple Plot that I want to add asymptote markers to: ...
0
votes
1answer
855 views

Syntax question regarding Triple Integrals in Mathematica

Integrate[1, {z, 0, 5}, {x, -Sqrt[ 9 - y^2], Sqrt[ 9 - y^2]} , {y, -3, 3}] 60 Sqrt[9 - y^2] How comes I am not getting a number for my final answer? This ...
3
votes
3answers
273 views

Product of edge weights in path

I need to calculate the product of graph edge weights on the path taking into account edge direction. I.e. for graph ...
4
votes
3answers
206 views

Border on part of ArrayPlot

I need to outline with border the group of cells in ArrayPlot. More precisely in my case I would like to outline all blocks of two black squares in the following line. ...
2
votes
1answer
162 views

How to frame a PairedHistogram and manipulate the frame ticks?

How can I Frame a PairedHistogram and manipulate the frame ticks? I want to specify and control the frame ticks in the paired ...
3
votes
2answers
176 views

Write list of polynomials as a matrix of coefficients times a list of monomials

I have the following problem: given a list of polynomials P = {p1, ..., pn} on the variables x[1], ..., x[n], find a list of ...

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