26
votes
14answers
16k views

Alternatives to Mathematica

Inspired by the recent question Alternatives to LaTeX (currently 58 upvotes) on http://tex.stackexchange.com/: Are there any paid-for or open source alternatives to Mathematica which produce equal or ...
1
vote
0answers
19 views

Question on ClusteringComponents

I am fairly new to Mathematica. I've been playing around with ClusteringComponents. Assume we are clustering points in the plane using k-means clustering and ...
2
votes
1answer
33 views

How to use an expression for the argument to a function

I would like to define a function over a list of variables like f[a_,b_,c_]:=a+b+c However, when this list is big it makes uncomfortable to read. Can I somehow ...
-1
votes
1answer
95 views

need help to price a european option using finite difference method [closed]

I am writing a function to price European option using backward induction finite difference method. The function is expected to price a European option taking Stock (stock_), age (time_), volatility ...
4
votes
2answers
321 views
+500

Probability: Calculating a multiple integral

Find the value of $P[\Pi_{i=1}^{10}X_i > C]$ for $C=2,5$, where $X_{10\times 1}$ is a random vector with $10$ dimensional Cauchy Distribution having location parameter $\mu_{10\times 1} = ...
29
votes
5answers
2k views
+500

How to efficiently find positions of duplicates?

Is there an efficient way to find the positions of the duplicates in a list? I would like the positions grouped according to duplicated elements. For instance, given ...
17
votes
5answers
1k views
+500

Moving maximum function?

How can I construct a moving maximum function? For example, if I have a list of 12 values: { 5, 6, 9, 3, 2, 6, 7, 8, 1, 1, 4, 7 } and I want to maximize over 3 ...
2
votes
2answers
103 views

WorkingPrecision causes issue in the NIntegrate

I really can't figure out why my code sometimes is not working. My integrals involve two variables (k and kz). The integration ...
1
vote
3answers
55 views

NDSolve parametric plot

Here is my code. s = NDSolve[{f'''[x] + f[x]*f''[x] == 0, f[0] == A, f'[0] == 0, f'[10] == 1}, f, x] I want to plot f''[0] ...
0
votes
1answer
67 views

WSMModelData Error

I am getting this error message when I run simulation in Mathematica that makes iterations to a SystemModeler model. ...
4
votes
4answers
252 views

Spiral roots, how?

I found this picture on the net, as I can play in mathematica
1
vote
1answer
54 views
0
votes
0answers
36 views

Matrix iteration failing after second step

I am calculating 11x6 matrix using different logics as in below code. Problem is in Do loop in below code where I have two different criteria to update matrix "fd". I am expecting logic in IF which ...
0
votes
1answer
33 views

Returning value if a point is in a region?

I'm writing a function so that if the user clicks on a certain region, a value is returned. The function takes in a condition list like the one below and a point. ...
0
votes
3answers
77 views

Manipulating List?

I have a huge list with 1000 elements.Manually entering and calculating SUM of probabilities it would take a few hours. an Example: list = {1, 2, 3, 3, 4, 3} ...
2
votes
1answer
62 views

Output an Expression in terms of GoldenRatio

Sorry if this is a dumb question (I'm new). I swear I searched and read forums first! I'm trying to rewrite expressions in terms of the Golden Ratio. For example, I know ...
16
votes
1answer
406 views

Analogue for Maple's dchange - change of variables in differential expressions

Maple owns an interesting function called dchange which can change the variables of differential equations, but there seems to be no such function in Mathematica. ...
11
votes
2answers
232 views

How to suppress Tooltip in built-in templates?

...or maybe switch the message. But I will be happy with no Tooltip at all. I've naively tried with ...
0
votes
0answers
20 views

Absolute VectorPlot scaling

I'm trying to visualize the vector components of a rotation matrix with absolute vector lengths. VectorScale Help states that When using an explicit sfun, positive values are automatically scaled ...
0
votes
0answers
28 views

How to invert the default order of polynomial?

By default, Mathematica outputs polynomials starting with smallest degree. How can I invert this?
0
votes
0answers
12 views

Possible bug of Exporting as HTMLFragment at Linux

This is the result of Mathematica 10.0.2 of Linux Version. There are two style inside one tag, and this fragment cannot be Imported as XML by Mathematica. This is the result of Mathematica 10.1 of ...
1
vote
2answers
144 views

Partition a range of integers into triples

Some time ago, I was asked to look at a simple to formulate puzzle. Consider the list of numbers {1,2, ..., 33}. Try to split this list in 11 triples, such that in ...
1
vote
1answer
20 views
0
votes
0answers
39 views

How can I make a plot of integer lattice?

I want to make a plot of complex plane with dots representing visible lattice points. I want the result represented somehow like this: ...
0
votes
0answers
21 views

Definition of function for integration

I have this function: g33[p_] = Integrate[1/(a - b) (a μ2[-p/b] + μ1'[-p/b] - 2 a g2'[(-a p)/b] - (a + b) g4'[-p]), {p, -l/b, 0}] And I want to call it with ...
-2
votes
0answers
68 views

How to compute and plot an intersection? [on hold]

When two surfaces (ParametricPlot3D based on two independent parameters or a CountourPlot3D or a Monge Plot3D with known formula) are placed and plotted together, how is the intersection line ...
0
votes
1answer
114 views

Formatting an equation: X^Y to pow(X,Y)

I am trying to solve for the intersection of two circles with arbitrary centers and arbitrary radii. ...
1
vote
0answers
16 views

ConnectedComponents problem of syntactic structure

In Mathematica 10, ConnectedComponent computes the list of vertices belonging to strongly connected components. In the following simple example with a graph with no edges, the result is as follows: ...
0
votes
0answers
22 views

Package for symbolic computation of christoffel symbols and parallel transports in Riemannian geometry, given the metric

I've no knowledge in mathematica (but I do in matlab), but I'd really appreciate if someone could mention what is/are the best and easy to learn mathematica package(s) for symbolic and numerical ...
0
votes
0answers
20 views

PeriodogramArray or PowerSpectralDensity?

could anyone explain what is the difference between PowerSpectralDensity[data,omega] and PeriodogramArray[data]? When I plot them (starting from the same set of data of course) I get two different ...
0
votes
0answers
45 views

I made my own equation, how do I know if it already exists? [on hold]

I made my own equation after playing around with some numbers. So I started to look for the equation to be sure I made it first. I googled and searched for it almost everywhere but couldn't find it. ...
1
vote
1answer
60 views

White Edges Around Graphics Elements

Using the following code, I am able to generate a grayscale Voronoi diagram: ...
1
vote
0answers
36 views

Plot a data of four dimension

I have a confusion recently about the visualization of data.the data you can get there enter link description here.The construction of data is four dimension,like as {x,y,z,color},this is my current ...
2
votes
0answers
30 views

Strange behaviour of suggestion bar to solve an ODE, potential bug

InputE^(-(1/2) x[t]^2) (Derivative[1][x][t]^2 - (x^\[Prime]\[Prime])[t]) == 0and evaluate, then press the solve ode button on the suggestion bar. It will return ...
0
votes
0answers
53 views

How to clear Mathematica's storage after a large computation? [on hold]

I've done some surfing and haven't found a solution to my problem... hopefully it is a simple one! Here is the problem. I have a Monte Carlo module that is stepping/tracking particles in a ...
0
votes
1answer
62 views

Arbitrary hollow cylinders in mathematica 9

I'm having trouble displaying a hollow cylinder in Mathematica 9. A hollow cylinder looks like this: I tried to use RevolutionPlot3D with a step function. It ...
3
votes
1answer
56 views

DynamicModule issues with Refresh, double evaluation, and CDF Player preview

I am in the middle of making a CDF for a calculation of many random variables. I've gone with DynamicModule and have read the documentation plus these posts: 32294 ...
1
vote
1answer
45 views

Numerical solution of IVP for linear ODE with variable coefficient runs wild soon

A friend of mine showed me this initial value problem (IVP) for a linear ordinary differential equation (ODE) with variable coefficient: $$y''(x)=\left(x^2-1\right) y(x)$$$$y(0)=1$$$$y'(0)=0$$ Seems ...
0
votes
1answer
29 views

More than one graphic in Graphics command [on hold]

another question regarding plotting. I'm sorry, but somehow it is superhard for me to use these. I have a Graphics plot and I want to add a Point to it. A circle is already working. But everything ...
1
vote
1answer
45 views

In WolframAlpha, how can I make a Scatter Plot without connecting points? [on hold]

How do I plot a list of points without connecting the dots in WolframAlpha? I tried, for example, ...
4
votes
4answers
164 views

How to fit a surface to 3D data in Mathematica?

I have a set of data coordinates which is mostly compatible with an Ellipsoid: {{x1,y1,z1},{x2,y2,z2}, ... , {xn,yn,zn}} Now I want to find the best 3d volume ...
0
votes
1answer
33 views

Replace element of matrix based on rule which invloves other element of same matrix

I am trying to replace 1s row of matrix d iteratively from right by multiplying last element in 1st row with (1-int*dt) to generate 2nd last element. The replacement continues till I reach the 1st ...
9
votes
1answer
131 views

Geocentric, Earth-fixed, coordinates of Sun, Moon (and others objects eventually)

I know I can get "HelioCoordinates" of the Earth and the Moon with ...
0
votes
2answers
48 views

Force Mathmatica to simplify an ArcTan[]?

I understand that there are many solutions that will produce the same arctangent, nevertheless I really need a simplification: ...
2
votes
2answers
158 views

Issue with Set function

Tables often come with column headers. Indexing the columns with the header is a natural thing to do. Although a proper dictionary is the usual solution in such a case, I find it often practical and ...
4
votes
2answers
96 views

Coarse-graining in numerical integrations

I have been working recently in a coarse-graining problem I found when using NIntegrate: I am trying to evaluate the function $$f(a)=\int_0^{\infty}x\,e^{-(a^2+b^2)x^2}\text{d}x$$ numerically as a ...
1
vote
2answers
107 views

How can I reshape my solutions to make a 3D plot?

I need some help on the following. I need to run Solve for multiple values of a and b. To do so instead of using Do, I use ...
2
votes
2answers
103 views

Dynamic arrays and lists with compile (Append, Linked lists etc.)

I have a code that I need to compile. The code contains a loop in which I need to gather data into a list. The question is how to best gather data so that the code works inside Compile. The following ...

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