6
votes
2answers
369 views

How do I transform a rasterized graphic's coordinates back to its original ListPlot data coordinates?

From this question I successfully made an elliptical fit for my data. However, when I try and collect the datapoints within the ellipse via this question the coordinates of my ellipse correspond to an ...
1
vote
1answer
255 views

Code to draw geometry doesn't run

I'm new to Mathematica and have no background whatsoever in programming, although I will teach myself soon. I was wondering if one of you programming pros could help me out. I received a code from ...
-1
votes
1answer
379 views

simplifying equations [closed]

I have a question that seems easy but I can't solve it. I have an equation like: eqgama = -8.33208*10^56 g1 + 8.18264*10^56 g1^2 == -1.42093*10^56 I use the ...
12
votes
4answers
608 views

Adding Lines to Sparklines (plots w/o frames, axes, etc.)

I have been working with Sparklines, thanks to some code found here. Here is what I am using: ...
10
votes
3answers
345 views

Generating Linear Extensions of a Partial Order

Given a set $S$ and a partial order $\prec$ over $S$, I'm looking for a way to "efficiently" generate a list of linear extensions of $\prec$. Suppose the partial order is given by a ...
6
votes
1answer
730 views

How to use and input audio wav file into a Wolfram demonstration

I am trying to send a Wolfram demo, which contains a sound wav file. sound = Import["C:/myfile.wav", "Data"]; snd := sound[[1]]; or snd = sound[[1]]; Is it ...
4
votes
2answers
754 views

Chain rule while differentiating

I am trying to find the derivative of a function defined in polar coordinates with respect to $x$ and $y$. My function is defined as follows: $ v_x(r, \theta ) = v_r \cos (\theta ) - v_{\theta }\sin ...
5
votes
2answers
251 views

Creating a list of PopupMenus that dynamically update an element in a list

So as the title says I am trying to make a list where each element is determined by a users choice of an element in a PopupMenu. My first attempt: ...
2
votes
3answers
2k views

Passing a matrix as a function argument

I am trying to do the following: ...
0
votes
0answers
206 views

How Can I Use Conditional with Rational Domain Restrictions [duplicate]

I am reasking this question in a new thread. My previous post How Can I Use Solve/Reduce Output? seemed to have led to a an interesting dissussion of how to (better) solve the problem that produced ...
5
votes
2answers
195 views

Delete contexts from a string representation of a symbol

I want to delete the string representing the context of a symbol. For info I need such a functionality in my ShowIt function defined here I'd like to know how I ...
6
votes
1answer
598 views

vectorial ODE in mathematica with matrix exponentials

I want to solve the following equation in mathematica : DSolve[{X'[t] == A.X[t], X[0] == ( {{0},{0}} )}, X[t], t] It is a system of 2 ODEs coupled by the matrix A, ...
6
votes
2answers
219 views

How do we turn off automatic smart quotes/special character substitution?

In Mathematica 8, whenever I enter "hello" into a cell of style "text", the quote marks are automatically converted to special characters: ...
4
votes
1answer
510 views

Can DSolve solve systems with unspecified function coefficients?

I am an economic research student with no previous experience with Mathematica, so please pardon me if my questions sounds really stupid. I am hoping to solve a system of nonlinear ODEs symbolically. ...
1
vote
1answer
406 views

Fastest way to sum pairwise potentials

I've been writing a function to sum a pairwise potential on two lists, i.e. two charged bodies, each containing N >> 1 and ...
10
votes
4answers
563 views

Reproducing Image Patterns with Mathematica

Surfing on the net I stared at this pattern. It´s a bamboo steam, and it´s awesome. I'm new to Mathematica so I'm a little lost, I'd like to try to reproduce this pattern, of course in a very ...
14
votes
1answer
534 views

Detecting and counting signals in list data: checking pulse rate

Hope this isn't too much of a basic question: I'm looking for some Mathematica functions, but I don't know which ones. Background I recently read about a simple technique for reading your body's ...
9
votes
4answers
582 views

Finding the roots of Hypergeometric1F1[]

I am trying to find the roots, λ, for this equation: Hypergeometric1F1[1/4 (2 -  λ /β), n + 1, β] for certain ...
9
votes
2answers
677 views

Preventing label crowding in PieChart RadialCallout and RadialCenter

Is it possible to avoid this unreadable situation with label crowding when using PieChart's RadialCallout and ...
3
votes
1answer
606 views

Mathematica - Dynamic - ListPlot - baseline

I am performing baseline fitting to a raw dataset on a two-state equilibrium process. The process involves fitting the sigmoidal curve to an upper and lower linear baseline, and subtracting so that ...
1
vote
1answer
226 views

How to print a message dialog window

I'm trying to figure out how to print a message dialog without printing the whole notebook. FrontEndExecute[FrontEndToken["PrintDialog"]] displays the print window ...
2
votes
3answers
237 views

How can I fix CDF Windowsize as constant

I want to make CDF WindowSize as constant so that the end user can not resize it either by dragging Window or by maximizing it. ...
5
votes
1answer
901 views

How Can I use Solve/Reduce Output

Suppose I want x and y to be rationals Solve[ x^2 + y^2 == 1, {x, y}, Rationals] I am ...
2
votes
1answer
385 views

PlotRange problems

I have a Delay Differential Equation of the form: ...
3
votes
1answer
487 views

Mathematica PDF import and fonts

I am trying to put nice LaTeX labels on my Mathematica plots. I can do this manually, or by introducing an extra GNUPlot step into my workflow, but it would streamline the process considerably if ...
2
votes
2answers
682 views

Plotting best-response functions

I'm a newbie in Mathematica. I'm trying to solve for two functions (best-response functions in a simple game), and then to plot the functions on the same graph. One function is p1 = resp1(p2) and the ...
3
votes
1answer
254 views

Could the PrecisionGoal for NDSolve be a negative number?

The help of Mathematica doesn't say so much about the PrecisionGoal for NDSolve, and I never considered much about it even after ...
3
votes
1answer
192 views

How to make a package for buttons

I am trying to make a Package for a piece of code though it's not needed here as it is very small. But my actual code here is a little bit different from that ...
20
votes
5answers
708 views

MapThread over sublists of different length

I have a list which looks like this: l={{1,0,3,4},{0,2},{0,0,1,3},{1,2,0}}. Now I would like to count how many 0s the sublists contain in the first, second,... ...
5
votes
1answer
272 views

Histogram3D frame ticks with bin text labels rendered in x-y plane?

Is it possible in Histogram3D to substitute frame ticks text labels and have the layout in x-y plane? Starting with a ...
11
votes
1answer
1k views

Persistence length of a polymer chain

I'm trying to calculate the persistence length (Lp) of a polymer chain using Mathematica. The first and simplest method is to compare the EuclideanDistance between ...
3
votes
2answers
202 views

How does RootOfUnityQ work?

How does Mathematica's RootOfUnityQ function work? That is, how does Mathematica know if a number is a root of unity? Example: Let $x = \frac{1-i \sqrt{2+\sqrt{5}}}{1+i \sqrt{2+\sqrt{5}}}$. Then ...
13
votes
4answers
2k views

Cut and paste data from a spreadsheet

I have a set of data points in two columns in a spreadsheet (OpenOffice Calc): I would like to get these into Mathematica in this format: ...
5
votes
3answers
170 views

StandardForm on Graph edges

The Graph command displays edge labels in TraditionalForm. I instead want to use ...
2
votes
3answers
298 views

Force VectorPlot3D to show One arrow

I am plotting a curl, and I only want VectorPlot3D to show one arrow, I have tried adjusting VectorPoints-> 1, but the plot show's no arrows at all. Is 2 the minimum VectorPoints I can have? If I ...
0
votes
1answer
644 views

Fourier series of interpolating function result of NDSolve

I am having a tough time formulating the right question but here goes. I know that solving the pde as in here gives me an interpolating function. I understand that the interpolating function object ...
7
votes
3answers
228 views

Get unevaluated option value?

This is kind of a follow-up to this question. I want to be able to define a function that takes an option, and then, inside the function, retrieve and test the unevaluated value of the option. For ...
2
votes
2answers
2k views

Automatically return output using decimals instead of fractions

I have a mathematica file with an algorithm that feeds another program with data. my problem is that some times (randomly) the output is in fraction instead of decimal. The other program (java) does ...
1
vote
1answer
177 views

Using block or module to free cache

I'm writing some code at the moment that schematically looks like: (set initial conditions for some differential equation for given parameters (M,R,...)) ...
3
votes
1answer
205 views

Using DynamicWrapper with multiple Dynamics with different TrackedSymbols

I have two variables A and B that are linked such that changes to one causes the other to be updated to the same value. However at each change I'd also like to know which variable cause the update to ...
12
votes
2answers
924 views

How do I split up a curve into segments of equal length?

I have a curve that is defined as f[x] and what I'm attempting to do is to divide the curve into equal straight lengths for a number of segments of my choosing that I've defined as nSeg. I've created ...
3
votes
2answers
147 views

How to create an ImagePartition type-of-function that generates parts of different sizes

Background: I partition images to polygons ( squares ) and color them with VertexColors. I want to use a minimal number of polygons while still showing a clear resemblance of the original image. - ...
6
votes
2answers
399 views

How to work out the parameter in a definite integration which has an exact value while the integration doesn't have an analytical solution?

Here is the equation I'm trying to solve: NIntegrate[1/(E^(1/(λ T)) - 1), {λ, 200, 220}] == 1000 T is the parameter I'm ...
2
votes
1answer
100 views

MathGraphicsJPanel no output

I am trying to create a Java frontend for Mathematica. Following examples from J/Link guide and looking around the API manual I came up with this code: ...
3
votes
2answers
230 views

Using the elements of a subset in a Do loop

I would like to use the elements of Subsets in a Do loop. I have: ...
3
votes
3answers
250 views

Incrementing a nested list element

I've been wanting to increment a nested list element of which I know the "coordinates". I thought of the following procedure, using Apply with Part. ...
3
votes
0answers
103 views

ProbabilityDistribution PDF on boundary points

I would like to evaluate the PDF of a custom ProbabilityDistribution at the min and max values. However, PDF[...] returns 0 at ...
7
votes
3answers
504 views

Specifying string patterns in DeleteCases

It seems that DeleteCases is not compatible with string patterns, at least directly (see, for example, this question). Is this true? If so, why is this the case? ...
10
votes
1answer
253 views

Formatting Framed - some FrameStyle graphic directives don't work?

The FrameStyle option in Framed seems to work for some graphics directives but not others, eg: Framed["yo", FrameStyle -> Blue] But ...
3
votes
3answers
118 views

Using NumberString, DigitCharacter, or a similar directive to find all string representations of integers in a string

I have a text file containing many, many lines of text like test in the following: ...

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