0
votes
0answers
70 views

Integration is unevaluated analytically after a variable removed

I am using Mathematica 9.0 to do a symbolic integration as follows: ...
2
votes
1answer
198 views

Plotting a pencil of lines

I want to plot a pencil of lines between line1 and line2 using a formula (alfa*(ax+by+c)+beta*(a1x+b1y+c1)), but it doesn't show me anything. ...
0
votes
3answers
142 views

How to take dot product of every element in a list?

I have a list of coordinates (coord): ...
1
vote
2answers
166 views

Simulation of LogNormal process for an asset pricing

I'm new to Mathematica programming, so forgive my rather unsophisticated question. I need to simulate 5000 "walks" of a process value (of a stock) that starts from its current value, at ...
0
votes
1answer
71 views

Strange long time evaluation of Series for fractional function

my problem concerns the Series command applied to a product of a rational function times a square root. This can be exemplified in the following way ...
4
votes
0answers
47 views

Odd behavior of FindFile

Running FindFile gives some odd results on my machine: FindFile["HTTPClient`"] Result: ...
-1
votes
1answer
137 views
2
votes
1answer
92 views

Part specification error with InterpolatingFunction when generating a Markov Modulated Poisson Process

I want to create a Markov Modulated Poisson Process, where the arrival rates created by the states of a ContinuousMarkovProcess are fed into an ...
2
votes
1answer
244 views

How do I get the adjacency Matrix from a random graph [closed]

I am using the command g = RandomGraph[{8, 13}]; GraphPlot[g, VertexLabeling -> True] to plot a random graph with n nodes and l edges. Once the program has ...
0
votes
1answer
115 views

Plot a function based on the value of another function

Could anyone guide me on how to plot the function VR with the values of ρ that I get from solving the following eq. ...
10
votes
4answers
284 views

Handy / flexible directory tree operations

Is there any shorter / more handy / more flexible way to get directory tree as a nested Rules/Associations list? I tried to incorporate ...
1
vote
1answer
52 views

Conditional Drop of a Key based on a test of the Value

I want to restructure a simple dataset. ...
0
votes
1answer
81 views

Symbolically solve system of equations involving matrix

I need to solve the following system of equations symbolically for a_i, b_i, and c_i: ...
0
votes
0answers
55 views

Some unexpected behaviour with StyleKeyMapping

Start with a fresh front end & kernel. The expected behaviour with an Input cell should be like this: Input 1and delete ...
1
vote
1answer
127 views

Extract coefficient matrix $A$ from expression $f(x)$

I have expression: $$f(x)=\sum_{i=0}^{K-1}\sum_{j=0}^{N-1}a_{i,j}e^{ix}x^j.$$ I want to extract coefficient matrix $A$ from expression $f(x)$ where $$A=\left( \begin{array}{ccccc} a_{0,0}& ...
11
votes
1answer
279 views

Is there a programmatic equivalent of Edit > Find…?

Most things that can be done via the front-end interface in Mathematica can also be accomplished by some function. Is that the case for find-and-replacing? That is, is there some code I could execute ...
2
votes
0answers
152 views

The idea behind Stiffness switching method with NDsolve [closed]

Does the Stiffness switching method with NDsolve switch just between multiple variants of 4th order Runge Kutta method or it uses also other methods?
1
vote
2answers
131 views

Integral too oscillatory

Is there any way top make this integral less oscillatory? ...
2
votes
1answer
210 views

Binary file gymnastics

I have an unformatted binary file generated by fortran 77 and i want to import it in Mathematica. The file is formed by 5 data arrays with double precission float numbers. The problem is that seems ...
0
votes
2answers
68 views

How to keep elements only if their first key is part of another list? [duplicate]

I have two huge lists: list1 and list2. I would like to keep elements of list1, only if ...
0
votes
1answer
128 views

Divergence in spherical coordinates as can be done in W|A

Is there any widget kind of thing that can work out calculations of vector analysis in not-Cartesiian coordinates, i.e spherical and cylindrical? Like the calculators found here: ...
0
votes
0answers
35 views

How to close the debugger window [duplicate]

So this thing just popped out of nowhere X.x ... I tried getting rid of it yesterday following suggestions in this post and I could've sworn it went away. But today I opened my laptop and the damn ...
9
votes
2answers
329 views

$\mathbf L\mathbf D\mathbf L^\top$ Cholesky decomposition

Mathematica can do a Cholesky decomposition $\mathbf A = \mathbf L\mathbf L^\top$, but how do I do a LDL decomposition $\mathbf A = \mathbf L\mathbf D\mathbf L^\top$, with $\mathbf L$ being a unit ...
2
votes
1answer
73 views

Computing large nested values

Is it possible to compute a value for n=10^9; Nest[# + Log[#] &, 2., n] for large n? $10^9$ seems to be the max for me - ...
1
vote
0answers
96 views

Calling a custom function in slave kernel process connected through mathlink [closed]

I am performing a small experiment to check if we can call/execute a custom package function in slave kernel launched from master using mathLink. I have created a dummy application called ...
2
votes
1answer
47 views

Modifying generalized input so there is no default input

I'm currently working on a demonstration and attempting to utilize the Interpretation command based on the example provided in the "Generalized Input" tutorial ...
2
votes
0answers
227 views

Factor out a constant from a matrix [closed]

I've got a matrix in which every entry is of the form x/4. I cant find out how to factor out the 1/4 so that the actual matrix is clearer. Thanks for your help!
0
votes
1answer
35 views

Dimension of plotting window vs PlotRange [duplicate]

For example, let's say I'm plotting this function, Plot[x, {x,-3,2}]. From the answer to this question the plot range is ...
0
votes
1answer
72 views

Problem with Erf near Infinity in NSolve

I have to solve a differential equation involving the error function Erf, but my code is not able to evaluate it in the range I need. I think I can formulate my ...
5
votes
1answer
327 views

Only `Break` from innermost loop

How could I Break from only the innermost loop in a Do[stuff,{i1,i1min,i1max},{i2,i2min,i2max},...] ? I get the desired ...
1
vote
0answers
149 views

Create trading chart from Bloomberg historical data [closed]

I am using Mathematica 9 with the Finance Platform, and have pulled historical data for the Bloomberg Commodity Total Return Index using the following code. ...
1
vote
1answer
166 views

non linear Least Squares with model function given by ODE's

I have to fit to experimental data a model function given by a linear combination of functions y1(t) and y2(t) a1*y1(t) + a2*y2(t) with a1 and a2 ...
2
votes
2answers
95 views

Need help with code for number theory problem

I'm completely new to Mathematica (used previously only for very simple cases). I need to write a quite complex function. The function must do the following: Input consists of two numbers: a and b. ...
3
votes
0answers
52 views

Indeterminate expression 0(I*Infinity]) on indefinite integrals on first use only

I do not know if this is new or not, I googled before. Windows 7, 10.1 64 bit: Integrals generate this error message The strange thing also is that the message shows up the first time the command ...
1
vote
0answers
110 views

Can Mathematica Find Closed-Form Solution this Equation [closed]

I have tries to solve an equation by using Solve[] to find pl as a function of other variables. However, it generates an Error! Can anyone help? ...
1
vote
1answer
67 views

How to transform ListPlot ticks

I am sure that this is a standard question, but I have not been able to find it, either by a google search or by searching here on the Mathematica StackExchange. If I have a list plot defined by: ...
11
votes
2answers
664 views

Generating uniform random points over a binary image

So I recently read this excellent post about generating random points over arbitrary regions. I hope Wolfram eventually builds that functionality into Mathematica's Random functions. I want to do this ...
0
votes
3answers
125 views

beginner's question: change a parameter while get variable answers [duplicate]

I'm new to Mathematica from R, since R is not quite good at dealing with the following problem. Say, i want to solve the function a x - 10 = 0. Each time I change the value of a, say, from 1 to 10 by ...
12
votes
1answer
138 views

Strange result of Reduce and ForAll

In the question Can Mathematica tell me if a polynomial has all real roots?, quite a few of interesting answers were given. I wanted to add another one, using quantors, and observed some strange ...
1
vote
0answers
101 views

Do not like quality of graphics when exported by Mathematica 9 [closed]

I have been using Mathematica 9 to generate images of fractals for some time, and I noticed an uncomfortable phenomenon when I export the fractal image into a PDF. The lines get thick so that the ...
1
vote
1answer
221 views

Running external program from command line

This command works on Windows: ReadList["!" <> "echo hello", String] Assuming the "!" suggests Windows command shell (verified as ...
0
votes
1answer
86 views

`Do` structures - listing iterated values

Please excuse the crudity / simplicity of this question, hbut I have never really got on too well with Do structures - perhaps I don't use them enough - perhaps I ...
5
votes
0answers
79 views

Applying functions to irregularly distributed Keys in Association lists

This Q is related to this one, but now refer to the situation as irregularly distributed Keys in lists of Associations: ...
19
votes
3answers
713 views

Why is calling Dot with many arguments so inefficient?

Say I want to multiply a reasonably large list of symbolic matrices. ...
4
votes
3answers
203 views

Factoring a separable integral with a product of independent integrands

I would like to input someFunction[Integrate[p[x] p[y], {x, -1, 1}, {y, -1, 1}]] and to get the following output ...
4
votes
2answers
74 views

Inconsistent Integration involving DiracDelta at boundaries

I'm working on integrals involving DiracDelta functions at the boundary of the integrals. I'm confused by the output Mathematica v10.1.0 gives me in this case: ...
2
votes
1answer
60 views

How can I get a manipulated parameter to show up with text next to it?

I'm trying to make a dynamic demonstration involving the $\epsilon-\delta$ proof of the limit, $$\lim_{x\to c}(2x-1)=2c-1$$ with the following code. d and ...
0
votes
2answers
393 views

Get constant term with `Coefficient` for a non-polynomial

Take a nonlinear equation such as exp = (x + 3)/4 + Exp[x] + 1 + (c + x) Note that this is not a polynomial. Now, I want to extract the coefficients of this. ...
3
votes
2answers
129 views
3
votes
0answers
69 views

How to match the arguments of the function in any order [duplicate]

The issue is the following, with a dumb function with (4) arguments of (4) different heads (for each head is always no grater than one arguments): ...

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