1
vote
1answer
82 views

Social Network Analysis - Get the List of InBoundEdges for Directed Graph

I wish to get the list of inwards edges for a node. IncidenceList provides both inwards and outwards list. I can of course filter with ...
4
votes
5answers
509 views

How can I name patterns in a Switch expression?

Suppose I have an expression and want to match it against successive patterns and return an expression corresponding to the first pattern that matched. In that case, I can use ...
15
votes
4answers
4k views

Plotting Fourier spectrum versus frequency of a signal

I have looked around here, and i am sure this has been answered, but i don't understand it. The thing is, I have taken a introductory signal processing course, and we had to use Mathematica, and i had ...
4
votes
1answer
209 views

PlotLegends and ImageSize

I have Mathematica 9.0.1, and I have problems with PlotLegends breaking the ImageSize directive. I defined ...
2
votes
1answer
103 views

Problem with Eigenvectors when given a matrix containing approximate numbers and symbols

I'm trying to diagonalize a certain 2 x 2 matrix, but Mathematica refuses to find the eigenvectors. In particular, when I input ...
5
votes
5answers
958 views

Label Markers On ListPlot

I would like to make a scatter plot where each element corresponds to a certain energy. Each plot marker should have its corresponding element next to it. IE. The data point at -1.16187 should have ...
4
votes
1answer
227 views

Can I enter the traditional form for Binomial as input in an expression?

Is there a way to enter the traditional form of a binomial coefficient, i.e. ${n \choose k}$ instead of Binomial[n,k], like I would enter a radical sign $\sqrt{x}$ ...
1
vote
2answers
153 views

How to fit exponential function which is not converging

I performed an experiment where I measured diffusion in a lipid bilayer. I performed the measurement by fluorescently labeling some molecules in the bilayer, and the irradiating them with light ...
1
vote
1answer
70 views

How can I get the functionality of a command ReplaceAllList?

I'm trying to use ReplaceList to match subexpressions. I expected the command: ReplaceList[{p, {p, p}}, {x_, y_} -> x y] to output two results, equivalent to: ...
1
vote
1answer
382 views

How do I get all possible solutions in an underdetermined system? [duplicate]

I have two problems which I'd like to solve with Mathematica. If I have a system of two equations with three unknowns, how can I get to list all possible solutions for the unknowns? Here is what I ...
3
votes
1answer
578 views

Solving a differential equation with initial conditions

I want to get a solution to an ordinary differential equation with imposed initial conditions. I'm confused about why my following code doesn't work: ...
1
vote
1answer
51 views

Padding sub-lists in a list [closed]

I have a list, say `Alist`` Alist = {{1}, {2}, {1, 3}, {4, 5, 6}, {4}}; and want a list, Blist such that ...
1
vote
1answer
789 views

Non-numerical value for a derivative on NDSolve function

I am trying to solve the following system of differential equations: ...
2
votes
0answers
98 views

Filling -> Axis leaves a gap

Filling leaves a gap between the function curve and the axis ...
3
votes
1answer
195 views

Put random points into a specific 2D subregion

I want to cover a particular subregion of the x-y plane with a random distribution. As this particular region is not a circle I encounter some problems declaring the permitted zone where to put ...
1
vote
1answer
113 views

Why does evaluating an integral within a Plot expression take so long? [duplicate]

I want to evaluate Plot[Integrate[Sin[((1 + 1/2) x)] (1/(2 Sin[(x/2)]) - 1/x), {x, 0, t}], {t, 0, 5}] but it takes ages to load on Corei3 computer with ...
0
votes
1answer
216 views

DSolve does not give solution

No answer is given when I evaluate the following expression: ...
0
votes
2answers
117 views

How can I compute the real part of $zeta^2$ numerically? [duplicate]

I want to compute and plot $Re((zeta(x+iy))^2)$ and $Im(zeta(x+iy)^2)$. How can i do that with Mathematica?
1
vote
1answer
130 views

Functions defined via inverse Laplace transform - plotting issue [closed]

I need to define a function $k(t,c_1,\alpha_1,c_2,\alpha_2)$ in the following manner: ...
1
vote
0answers
194 views

Runge-Kutta-2 on System

After spending some time using the Mathematica documentation and this Mathematica.SE answer, I implemented the Runge-Kutta-2 routines. I am hoping someone can validate what I did and tell me that it ...
3
votes
1answer
620 views

Select row from a table by column value [duplicate]

I have the following: animals = {{dog, black, 200}, {cat, white, 100}, {moose, brown, 500}, {zebra,black,100}} If this came from a SQL table called animals, ...
0
votes
1answer
158 views

Another 3D plot question- good and ugly but no bad-

I have the following code with the intention to have a 3D plot: ...
1
vote
1answer
206 views

Solution of an ODE in implicit form

For some non-linear ODEs there is only implicit form of solution using DSolve. For example DSolve[(y[x] + x - 1)*y'[x] - y[x] + 2 x + 3 == 0, y[x], x] gives ...
13
votes
1answer
679 views

Animating moving surface of torus

I would like to try to recreate something similar to Paolo Čerić's torus animation: I have isolated the moving surface torus section form this Wolfram Demonstration by Kevin Sonnanburg: ...
32
votes
2answers
1k views

Sketch-type graphics with transparency and dashed hidden lines?

I'd like to create transparent graphs like the following from P1095, Calculus 6th Ed, by James Stewart. Can Mathematica accomplish this? By "transparent," I mean the ability to see the interior, ...
1
vote
2answers
654 views

How to use ContourPlot3D for Piecewise 3D function

How would I plot in 3D: $\begin{cases} (4 - z^2) = x^2 + y^2, 2 \le z \le 4 \\ x^2 + y^2 = 4, -2 \le z \le 2 \end{cases}$. I tried http://reference.wolfram.com/mathematica/ref/Piecewise.html ...
1
vote
2answers
176 views

Organizing Code [closed]

Are there any recommended ways to organize code? THe simulation project I'm working on has gotten a little unwieldy. I've read up on packages but have never used them before. It seems fairly ...
11
votes
1answer
356 views

Fit two intersecting straight lines in Mathematica

I am trying to do a Kurie analysis of the double beta decay of Strontium-90. Here we have two straight sections, and I need to obtain a value for the intersection along with an error for it. I ...
0
votes
1answer
85 views

How to read long numbers? [duplicate]

Now, I have a data file (abc.dat) and it includes many long-Fortran-like numerical numbers as follows, ...
2
votes
1answer
126 views

Make FactorInteger print its result with CenterDot and Superscript?

I know that if I use CenterDot @@ (Superscript @@@ FactorInteger[x]) Mathematica will pretty print the output. However, is it possible to tell Mathematica to ...
9
votes
1answer
289 views

Wikipedia People only search

I am trying to search people from Wikipedia(For example .*John.* in REGEX). The following query is close, but it isn't generalized like ...
2
votes
3answers
142 views

String formatting

I have the following string: "174,861.00 ( 4,053.52) 206,850.48 118.29 ( 31,989.48)" Parentheses stand for negative numbers. I will like to get ...
2
votes
1answer
97 views

Restoring the 1-to-1 correspondence between elements in two lists, where one list is used as a guide to prune elements from the other

when we wish to use one list to select items from another using something like Pick, writing the following code, for example, causes us to lose the 1-to-1 ...
1
vote
1answer
198 views

Computing intersections between a large number of sets: doing it sequentially vs. sending everything to Intersection[…]

Say we want to compute the largest common subset among a very large number of sets $Q_i$. One option would be to simply run the command: ...
1
vote
1answer
157 views

How do I use wildcard characters with StringTake?

Say I'd like to pick substrings from some string such that these substrings have the pattern @@@q@@@, where @ is used here as a ...
1
vote
2answers
152 views

MapThread with List Manupulation

I have the following three lists: ...
1
vote
0answers
87 views

Import LaTeX from Wikipedia to Mathematica [duplicate]

Here is one a problem I land on from time to time. Sometimes while researching, I want to pull a formula presented in a Wikipedia page and import it into Mathematica. I've heard that Wikipedia uses ...
0
votes
1answer
100 views

AstronomicalData not including units?

I like using mathematica to do my physics homework, and AstronomicalData is useful for that, but it doesn't seem to work properly with units. [the question is, at ...
2
votes
2answers
677 views

Index-based Array splitting

I have an array of arbitrary elements, say strings: testArray = {"String A", "String B", "String C", "String D", "String E"}; How can I split this into two ...
2
votes
1answer
304 views

Gray background in export pdf

I am trying to output a simple plot with a legend and the output keeps coming out with a gray background. A simple example is the following: ...
8
votes
2answers
171 views

Half-delayed evaluation

In a certain wider context, I need to make some delayed definitions, such as x := a + b + c, but within these definitions I want ...
3
votes
1answer
192 views

Social Network Analysis - Get the End Points of an Edge

I want to get the end points of an Edge of a Graph. For example see the following source, ...
2
votes
2answers
233 views

Defining a function that returns “undefined” if its value is outside of a specific range

I want to define a function f(x) which: $f(x)=x^3 +10x+ 5$ if $f(x) >0$ $f(x)=Undefined$ if $f(x) <0$ I have a idea: ...
1
vote
1answer
139 views

How to replace a list with the result list after each iteration [closed]

I have some initial values such as L1 list: L1={10,20,30,40,50}; I want to use the L1 ...
1
vote
2answers
94 views

Decomposing a large text file, with alternating headers and text, into an array of headers and an array of text segments

I have a very large text file, test.txt, in the following format: ...
0
votes
1answer
217 views

How to prepare (copy/paste) data from Matlab?

What is the best way to get data from Matlab to Mathematica? For a new project I want to copy/paste a table (or part of it) of datas from Matlab to Mathematica. Copyed from Matlab it is: ...
0
votes
1answer
83 views

How to constrain the range of a plot o f a function to satisfy an inequality?

Given the function f[x_] := x^2, how can I plot f[x] over the region where f[x] >= 10 and ...
3
votes
1answer
230 views

Polar Differential Equation

I have a polar differential equation (this is the reduced variant) as: $$r' = 0, \theta' = 1$$ I figured out (from previous answers) that I can nicely convert this to Cartesian and use StreamPlot ...
0
votes
1answer
207 views

curve on the surface [closed]

I have a bezier polygon aa=Table[{i^2.5, 2*Sqrt[i]}, {i, 1, 5}],is anyone can give me a example in Mathematica code that how to create another iso parametric curve on this bezier surface?Display the ...

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