16
votes
1answer
250 views

Bug in RepeatedNull?

RepeatedNull appears to be buggy (versions 8.0, and 9.0). Define f as follows: ...
14
votes
3answers
2k views

How can I implement the method of Lagrange multipliers to find constrained extrema?

I want to form the function $h=f-\lambda_{1}g_{1}-\lambda_{2}g_{2}$ where $f$ is the function to optimize subject to the constraints $g_{1}=0$ and $g_{2}=0$ so that I can solve the first partial ...
0
votes
0answers
109 views

How can I calculate all irreducible polynomials of 31 degree in $\mathbb Z_2[x]$?

How can I calculate all binary irreducible polynomials of degree 31? or how i calculate all irreducible $f$ in $\mathbb Z_2[x]$? (The irreducible polynomial in $\mathbb Z_2[x]$ and $\mathbb R$ are ...
1
vote
1answer
206 views

using a Mathematica function to define a new function

I'd like to define a function of three variables which produces a new, named function of a single variable, where this final variable is not a member of the first three. So I'd like something where I ...
1
vote
2answers
223 views

NDSolve - 2nd order ODE - how to solve for y and y'

i am trying to workout how to solve a simple 2nd order ODE for y and y'. I can solve for y[t] as follows but how can i solve for y[t] and y'[t] ? ...
2
votes
3answers
1k views

How do you plot level curves describing a 3d surface on the x-y plane?

I am trying to plot several level curves of the cone: [x=ucos[v], y=usin[v], z=u],[0<=u<=2,0<=v<=2Pi] in the x-y plane. Does anyone know how to do this? Thanks
1
vote
3answers
99 views

Efficient matrix multiplication

I have a list of vectors vecs={vec1,vec2,...,vecN} where veci is a list with length N. Now I have a matrix N*N called mat. I would like to efficiently get all the numbers veci.mat.veci for i=1 to N in ...
0
votes
3answers
180 views

Labeling different curves on a LogLinearPlot

I have created a couple of two-variable plots of the form f(x,y)=x*y where there's a number of result curves, each representing an answer (image example below). ...
12
votes
1answer
2k views

Logarithmic scale in a DensityPlot and its legend

I was recently faced with the task of creating a DensityPlot with a logarithmic colour scale, and with providing it with an appropriate legend. Since I could not find any resources to this effect on ...
9
votes
1answer
631 views

How does Mma compute Confidence Intervals?

I am trying to understand how Mma computes the Confidence Intervals after a NonlinearModelFit. Consider the following example: ...
4
votes
2answers
159 views

Find a notebook I had open recently

I worked on a notebook a few weeks ago and now I can't find after looking through the most likely directories. The recent list only has 6 items in it, none of them the notebook in question. Is there a ...
6
votes
1answer
139 views

J/Link: Callback from J/Link into Java when Mathematica process terminates?

Is it possible to get a callback from J/Link into java when the (remote) link closes or the Mathematica process is terminated (killed) altogether?
5
votes
1answer
234 views

Place title outside of GraphicsGrid in Manipulate

I want to be able to place a text title centered just inside the bounding box generated by Manipulate yet above the GraphicsGrid and run boxes you see when ...
5
votes
1answer
198 views

How can I use a recursive function in a Module

I have a question about using a recursive function in a module. I made the following example to illustrate the question. The followwing code works: ...
5
votes
3answers
429 views

Solving recurrence sequence using an ODE

I'm trying to solve the recurrence a[n] == 0 for n < l a[l] == 1 a[n] == (l + 2(n - l) a[n - l] + (n - l)(n - 1) a[n - 1])/n(n - l + 1) for n >= l using ...
1
vote
4answers
243 views

Add Brackets to a string list

Hello stackexchange community! I have a stringlist with a value and his error for eg: {{"12","1"},{"13","2"}} Now i want to output this as something like this ...
2
votes
1answer
128 views

Generating a power series expansion of the function with parameter

I'm trying to generate a power series expansion of the following function: ...
17
votes
1answer
260 views

Making code version aware

Mathics, a free Mathematica-compatible project has been recently launched. It provides a subset of the functions and capabilities of Mathematica at a slower pace. This opens us the tantalizing ...
3
votes
1answer
3k views

Enlarge the axes text

Plot[Sin[x^2], {x, 0, 3}, AxesLabel -> {"x value", Sin[x^2]}] In the above code give a graph. In the graph the axes fonts are too small. My problem is that, ...
0
votes
2answers
134 views

Outputting a film (in .avi, .mp4, etc. formats) where frames correspond to Graphics3D outputs

I'd like to make a exportable film (in some format like .avi or .mp4, something playable on most computers) where each frame is a Graphics3D output. For example, we might generate frames in the ...
1
vote
2answers
2k views

How to remove ConditionalExpression from output

I need define the function with parameter so I could directly generate a power series expansion. The problem is that in some cases ConditionalExpression appears in output. Here is my code: ...
4
votes
2answers
159 views

NMaximize the Likelihood

I am still pretty new to Mathematica, but have to solve a quite complex problem. The function ...
7
votes
1answer
3k views

Entering numbers in Scientific Notation?

I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
3
votes
0answers
218 views

Optimization with Matrix value constraint

I am trying to find the orientation and position of a polygon resting on a curved surface under gravity.The polygon MUST not be penetrated by any part of the surface below. Here is an example for a ...
6
votes
1answer
474 views

Mathematica 9 Citation

I want to cite Mathematica 9.0.1 in my paper, but the standard citation is not available here http://support.wolfram.com/kb/472. Can you let me know where I can find it or give me one good sample (I ...
4
votes
1answer
351 views

Strange result for the analytic integration leads to Hypergeometric2F1

The integration result for Integrate[1/(r^2 Sqrt[x/r^(4 - 2 \[Gamma]) + 1]), r] is: ...
1
vote
1answer
584 views

Solving a system of non-linear differential equations

I want to solve the system of non-linear differential equations given below numerically. $$y''(t)+500y'(t)+100y(t)=-33\cos(500t)-66\cos(1000t)$$ $$300x'(t)=1000y(t)+500y'(t)-35\tanh(50x'(t))$$ ...
4
votes
2answers
302 views

How to determine coordinates of a shape in an image?

I have a pre-processed image, from which I have to get coordinates of some components. There are 7 green components (pigs actually) that I have already isolated from an angry bird screen shot. So ...
3
votes
4answers
247 views

Pattern matching in nested lists

I'm sure this has been asked before, but I can't find the right combination of search keywords to find it. Apologies. I want to do a ReplaceAll on a list of lists, ...
1
vote
1answer
149 views

Plotting - recursive

Slightly clearer, hopefully: I would like to plot Solve[Normal[Series[E^(n x), {x, 0, n}]] == 0 for incrementally increasing n, and show all plots overlayed. Here is my effort with up to n=63 using ...
14
votes
2answers
386 views

Change base font for all graphics objects

How can I change the base font style for all graphics objects, including the ones generated using plotting functions? I would like to change this a single time and have it affect all graphics ...
5
votes
1answer
346 views

ListPlot3D of a set of points in a non-convex region

I would like to plot a set of points in the same style as ListPlot3D does, but only in a non-convex region that I can specify (e.g. using a ...
5
votes
2answers
400 views

How to import a “.numbers” spreadsheet?

Does Mathematica support importing a ".numbers" spreadsheet file (from the "Numbers" '09 (ver. 2.3 554) spreadsheet program in Apple's OS X iWork office suite)? A ".numbers" file is actually a zip ...
0
votes
3answers
198 views

Conversion of binary matrix of mlf into multilinear function, any ready function for this?

I convert here only one term $x_1x_3x_7$ from the binary matrix by first getting the reversed binary 1010001 and then miggling with the data. I know I could convert the columns into binaries and then ...
1
vote
2answers
62 views

How to get monomials multiplied by each other?

Suppose Subscript[x, #] & /@ {1, 3, 7} that returns {x_1,x_3,x_7}. Now how can I get ...
1
vote
1answer
63 views

How to extract data beginning on the closest number to zero?

I have a list from which I want to extract only the values beginning from where b (from {a,b}) is the closest to zero. For example: I want extract data={{2, -0.036704}, {56.7499, 0.95489}, {73.7349, ...
4
votes
1answer
327 views

Specifying coordinates for Inset on a LogPlot

If I use Epilog->Inset within a Plot, the coordinates specified within that Inset match ...
4
votes
1answer
164 views

Dark artifacts in mathematica plot

When plotting in Mathematica I just got some "dark artifacts". Here is my code: ...
2
votes
2answers
227 views

Calculate information entropy integral in infinite square well problem

In the context of information theory, entropy is a measure of uncertainty of a random variable. In quantum mechanics, the uncertainty principle states that $\Delta x\Delta k \ge 1/2$. The same can be ...
0
votes
1answer
131 views

Export vector images

I am having difficulties exporting vector graphics. Using Kardashev3's code provided here: ...
0
votes
3answers
149 views

Speed up manipulate by exporting each step as an image

Consider a manipulate function such as: ...
1
vote
1answer
193 views

Show multiple plots with single variable

Using the same example code as in this question, is it possible to show all 10 plots (ie, each step of the manipulation) simultaneously? If a manipulate function is a series of listplots based on a ...
8
votes
6answers
724 views

How to draw symmetrical parts of a circle

Let's consider the following simple case: ...
9
votes
1answer
348 views

Inconsistent results of second derivative of inverse fourier transform

I am trying to get the Green's function of a toy diffusion equation $$\frac{\partial^2 u(x,t)}{\partial x^2} = \frac{1}{\alpha^2}\frac{\partial u(x,t)}{\partial t}$$ with Mathematica 9. Then solve ...
0
votes
1answer
87 views

How do you ContourPlot3D an implicit function of x,y, and z?

This is what I am trying to do: ContourPlot3D[4 Log[x^2 + y^2 + z^2] == 1, {x, -10, 10}, {y, -10, 10}, {z, -10, 10}] but all I get is the empty box. Can anyone ...
2
votes
1answer
111 views

Why is FileNameJoin not working?

I can not figure out why the code below doesn't work? aaa >> FileNameJoin[{Directory[],"input"}] error message came out saying OpenWrite::noopen: ...
2
votes
2answers
387 views

Is there a way to plot a single level curve of a function of x and y through a given point?

For example, I am trying to plot the single level curve of f(x,y)=xsin[y/x]+ysin[2x] that goes through the point (3pi,3pi). Can anyone show me how to do this?
3
votes
2answers
149 views

How to partition a list according to a nested table structure?

This question is related to this quesion. The goal is to use ParallelMap to map a function to a nested Table to get the ...
-1
votes
1answer
236 views

Efficient Table Generation & NDSolve Error

I'm currently working on solving an SEIR model with data from the CDC. I've created a function to calculate the Square difference for the model and want to create a table of values for the 4 variable ...
3
votes
3answers
148 views

Lists - pairing up

I have two (fairly large) lists of equal length & would like to pair them up. eg - from: a = {{0, 1}, {0, 2}, {0, 3}}; b = {{1, 2}, {1, 3}, {1, 4}}; I would ...

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