5
votes
3answers
164 views

Prevent iterator name from being confused with symbol passed into function body

I have a massive amount of code with lots of Table and Sum inside a Module. Each with their ...
5
votes
1answer
232 views

Mathematica 10 crashes when kernel is quit from MenuItem

I'm actively developing a large codebase that I load every time I use Mathematica. I frequently quit my kernel and reload the codebase to incorporate new changes. I've created a custom menu by editing ...
1
vote
1answer
162 views

Under what conditions does Mathematica give a natural antiderivative when integrating?

Natural antiderivative is defined as follows, using Fourier transform: $$f^{(-1)}(x)=\frac{i}{2\pi}\int_{-\infty}^{+\infty} \frac{e^{- i \omega x}}{\omega} \int_{-\infty}^{+\infty}f(t)e^{i\omega t}dt ...
10
votes
4answers
434 views

What is the correct way to use specific rule for specific pattern match when parsing an expression?

update: Thanks for the answers below. But I noticed they do not handle the following special cases: lis=1 and lis=z , ...
2
votes
0answers
208 views

Error when using EquationTrekker

I just got to know EquationTrakker because I need to do phase graphs for my classes. When I load it ...
9
votes
2answers
251 views

Keep Mathematica from simplifying functions with a specified Head

I want to run Simplify and/or Refine on various expressions, but keep it from touching anything that contains a specific ...
4
votes
1answer
172 views

Optimizing a function containing a complex exponential

I've noticed the following significant different in performance for different formulations of the same function: ...
6
votes
3answers
214 views

Isolating string characters

I have the following string: ...
22
votes
0answers
366 views

Can code optimize code?

Are there functions, programs or packages that deal with optimizing mathematica code i.e. re-writing ineffecive or convoluted code. -This question has haunted me since I joined SE. The background for ...
0
votes
1answer
46 views

Ivar error with Fit inside Plot

I'm trying to plot this Plot[Fit[med,{1,x},x],{x,0,10}] Why this doesn't work? I find out that if I do ...
5
votes
1answer
174 views

NDSolve solution violates initial conditions

I have the following code: ...
10
votes
2answers
383 views

How can I only draw outer common tangent to two circles?

I have code worked for drawing common tangent lines to two circles(http://en.wikipedia.org/wiki/Tangent_lines_to_circles), now I want to delete the inner common tangent lines, how? ...
7
votes
1answer
329 views

How to find the positive region of this function?

I'm new-ish to Mathematica and I'm using it to learn the basics of derivative trading (for fun not for trading!). I've defined a simple function to calculate the pay off of a trading on a call. I have ...
4
votes
3answers
193 views

Plot failing over set domain with any functions

I'm here with a rather interesting problem which I have no clue how to fix. I am trying to plot a function: Plot[x && 0 <= x <= (1/8), {x,-9,9}] ...
2
votes
2answers
190 views

ToExpression from commandline [duplicate]

I like to use Mathematica 8.0 from the commandline, then I just have to SSH in, no matter where I am, and go. I also like to do this without forwarding X, because that is slow and lags on my ...
6
votes
2answers
159 views

Is there a built-in function to map a list of heads to a list of data?

Assume that this built-in function is called func. What I want is func[{f,g},{a,b,c}] will return the following result: <...
5
votes
1answer
467 views

How to graph the revolution of solid limited by 2 points in x axis [duplicate]

I'm learning how use this program. And I have problem with how graph the solid of revolution.Here i write one exercise. y=2-1/2x, y=0,x=1,x=2; about the x-axis. This is the graph also the volume x=...
4
votes
2answers
249 views

Problem with machine number precision in compiled functions

When I compile a very big function and give it input the function returns error. I realized that this is because the value of the function becomes smaller than the smallest machine number. Is it ...
3
votes
1answer
102 views

Part specification error only in LogPlot

I've a problem. I defined a simple list and a function like below: lst := {5, 10, 20} f[m_] := lst[[Floor[m/10]]]; and drew a plot ...
2
votes
3answers
129 views

Dependency injection - use a specific implementation of one function within another

Consider... f[x_]:=Body containing h[some args]... g[x_]:=Body containing h[some args]... However I want to define something like... ...
5
votes
2answers
458 views

Find file names in directory

I am trying to find the list of any file in any directory of a given name (by in the directory, I mean directly in the directory, so in a directory which is in the directory would not count). For the ...
34
votes
8answers
2k views

How to generate random points in a region?

The Mathematica 10 documentation was updated for FindInstance adding support for regions. In my use case, I'm trying to sample points in a set of disks: ...
4
votes
3answers
144 views

Help with coding triangular nodes/elements

I'm trying to write a program where it will shoot out the triangle node numbers. For example, in the picture, if we choose to divide this triangle by 5 points, then the program will return out the ...
6
votes
2answers
346 views

Importing multiple images for machine learning classification

I want to create a ML classifier using images just like this example. I have two classes of images in two different folders. Is there an easier way to import all images from both folders rather than ...
3
votes
0answers
86 views

How to solve for exponents in an infinite product?

Say I have a power series, $f(x,y) \in 1 + x\mathbb{Z}[[x,y]]$ Then it admits a unique expansion $$f(x,y) = \prod_{i=1}^\infty \prod_{j=0}^\infty (1 - x^i y^j)^{n_{i,j}}$$ for some integers, $i, j$....
6
votes
2answers
159 views

Return value of Reap when using tags

I've noticed a behaviour of Reap that I don't quite understand yet. Suppose I want to Sow several values during a computation. <...
1
vote
1answer
185 views

Horizontally compress a picture with varying compression ratio

I have a function c[x] whose domain and range are both [0,1]. And I have a picture with width W, height ...
11
votes
0answers
548 views

How to export .mtl files for 3D textured objects

I would really like to deploy my textured 3D graphics in the web with sketchfab in my blog. Unfortunately, Mathematica only exports the shape of the 3d graphics, i.e. the .obj file, but omits the ...
2
votes
0answers
276 views

Two problems with NDSolve when using Method -> Projection

I tried to solve a system first order differential equations together with a constraint equation. I use the Method -> Projection to check if the constraint holds ...
1
vote
1answer
269 views

Window ▶ Show Handwriting Input

How might I force Mathematica to display the Handwriting Input menu? Currently I'm on W7 using a Wacom Tablet and unable to find the Handwriting Input option. It doesn't display under Windows>.
6
votes
3answers
430 views

How to count the integer grid numbers defined by inequalities?

I have the following code to show a red area defined by inequalities: ...
6
votes
4answers
2k views

DSolve not finding solution I expected

Try to solve the following ODE via DSolve $$ \left\{\begin{aligned} y'(x)+2 y(x) e^x-y(x)^2 &= e^{2 x}+e^x \\ y'(0) &=1 \end{aligned}\right. $$ The ...
0
votes
0answers
105 views

Lightweight Grid preferences screen stopped working after v10 install

I am getting the following error when I try to open the Lightweight Grid "Preferences" tab... ...
3
votes
1answer
156 views

May I restrict caching to disk when memory runs low? [duplicate]

An hour ago, I had to hard reset my laptop again because Mathematica froze the system again. When import a large file or make a mistake that produces huge arrays with complicated entries etc., I often ...
18
votes
4answers
430 views

Make MapIndexed listable

My goal is to apply MapIndexed to every element of a nested list without destroying the arithmetic operations within the elements. For example, let's start with ...
1
vote
2answers
69 views

How to use the output we see of expression when this expression is inside Dynamic

Consider this example: Manipulate[status = Dynamic[If[a < b, Yes, No]], {a, 2}, {b, 5}] The output of this calculation is ...
1
vote
2answers
697 views

Computing 10-dimensional volume of a 9-sphere [closed]

I'm trying to compute 10-dimensional volume of a 9-sphere with radius r using Monte Carlo. ...
8
votes
1answer
155 views

On using DiracDelta[t] in OutputResposne in version 10. Different result from version 9

I am baffled by this. I was trying to run same example I had working in version 9.01 and found now I get empty plots. The example is here . Here is a simplified version of the above. The same exact ...
1
vote
1answer
143 views

Connect to Windows kernel from Linux computer

I've seen many questions regarding the connection to a Linux machine from a Windows one, but I need to do the opposite. Situation: I have Mathematica on my Linux laptop (...
21
votes
1answer
1k views

Is it possible to insert new colour schemes into ColorData?

Because of the standards in my field, for many plots I need to use (or at least end up using) rather narrowly defined colour schemes, and in particular the Matlab "Jet" scheme, which is well described ...
7
votes
3answers
229 views

Different results with DateRange and LeapYearsQ in Mathematica 9 and 10

With Mathematica 9.0 for Mac OS X x86 (64-bit) (January 24, 2013) one could use DateRange[{2000}, {2010}, "Year"] to achive ...
4
votes
1answer
213 views

How to vary line thickness to add a sense of perspective?

Is there a simple way to vary the line thickness relative to the viewpoint so as to add a sense of perspective? Take for example the following: ...
1
vote
0answers
249 views

Calculate the power spectral density of a Markov chain

I would like to calculate the symbolic power spectral density of a two state Markov process with a symbolic transition matrix characterised by two parameters. I have tried the code below, but it ...
12
votes
2answers
617 views

Map of United States as a 3D histogram

By combining the state data from here and the extrusion code from here I have managed to make prisms of the various US states such as However, the extrusion method looses information about the ...
1
vote
1answer
96 views

How to apply a trigonometric identity to a formula

The product of cosines is given by (Wikipedia): $ \prod_{k=1}^{n} \cos{\theta_k} = \frac{1}{2^n}\sum_{e\in S} \cos(e_1\theta_1+\ldots+e_n\theta_n) $ where $S={1,-1}^n$. How can I apply this to a ...
13
votes
2answers
637 views

Automatically add appropriate prefix to Quantity

Is there a function that automatically adds the appropriate prefix to a Quantity object? For example, I would like a function ...
8
votes
2answers
347 views

FullSimplify giving unexpected result

When I perform a FullSimplify on the list $$ \left\{-\sqrt{5-2 \sqrt{6}},\sqrt{5-2 \sqrt{6}},-\sqrt{5+2 \sqrt{6}},\sqrt{5+2 \sqrt{6}}\right\} $$ I get $$ \left\{\...
3
votes
2answers
169 views

Expectation of a composite Markov-Gamma distribution

In a model I have a discrete two-state first order Markov process, defined by a (2x2) transition matrix with two free parameters. If the first state occurs then the process outputs zero for that ...
2
votes
3answers
398 views

How can I apply calculus to functions obtained from NDSolve?

Originally, I asked the question below, but the real underlying issue is as follows: When we solve an ODE numerically, I get the answer like this: ...
2
votes
0answers
54 views

How to expand set of fonts for mathkernel.exe?

If I am running standard Mathematica and I am choosing from the menu Format->Font, I've got everything I need. All necessary scripts are present (Western, Central European,etc.). Whereas If I run ...

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