0
votes
1answer
93 views

whats wrong when I use for loop for creating a matirx? [closed]

When I use separate value for "i" and "j", I got the correct desirable answer. a = 2; i = 3; j = 3; !(*SubscriptBox[(matrix), ([([a])])]) = {{1, 1, 3}, {7, 4, 7}, {2, 6, 8}}; value = ...
2
votes
1answer
72 views

Algebraic Manipulations with Indices

I am absolutely new to Mathematica, but I've heard it is a pretty powerful tool for symbolic calculations. My problem (stated generally): I have three dimensional array. I define a symbolic operator ...
5
votes
2answers
180 views

Trouble with ParametricNDSolveValue

I have this: ...
0
votes
2answers
72 views

NIntegrate fails when integrating over a list from an external (MathLink) function

NIntegrate fails when integrating over a list from an external (MathLink) function. For simplicity, consider an external function f[x] that returns the list {x,2x}. In Mathematica, the function would ...
0
votes
0answers
43 views

What is the right way to remove head of a number? [duplicate]

I often have a number for which I want to remove its head, e.g. {1}. I know of two ways to remove the head: {1}[[1]] # & @@ {1} Neither of these methods seem ...
5
votes
1answer
97 views

Dynamics and Block interfere

As mentioned by Albert Retey in a comment, we can unintentionally interfere with our dynamics as follows ...
6
votes
2answers
342 views

Using NDSolve to produce 10,000 points of a solution

I am beginning to read the Differential Equations Laboratory Workbook by Borelli and the preface begins with an image. I understand how to use NDSolveValue (at a ...
17
votes
0answers
232 views

Is MathieuC for moderately large imaginary arguments broken?

I'm trying to plot MathieuC[-3,0.3,I x] for $x\in[0,10]$, and here's what I get even with arbitrary precision arithmetic (here I use ...
3
votes
2answers
210 views

Plot 2d-ItoProcess data in a plane

I am trying to simulate a simple 2d Ito SDE (randomly perturbed Hamiltonian system). Below is the code. ...
3
votes
2answers
91 views

Select elements from list with given head

I would like to select elements from list by specifying their head. E.g. SelectWithHead[{1,2,3.5,x}, Symbol] = {x} SelectWithHead[{1,2,3.5,x}, Real] = {3.5} What ...
4
votes
3answers
301 views

How do I draw random points from a region [duplicate]

as the title,this problem have confused me a whole day.If I have a region,how can I yield a random member in this region.The region such as ...
1
vote
1answer
169 views

How do I create a histogram of the binomial distribution for, say, p=.5 after 10 trials?

I apologize if this is question is too simple, if so it's because I'm a beginner. Anyway, it was easy enough to create a list plot, but I couldn't find out how to create an output that displays the ...
1
vote
2answers
78 views

BoxWhiskerChart Vertical Line

I have made a box plot to show the spread of past paper results for my A2 exams so I can easily see which subject need more work! ...
2
votes
1answer
107 views

How to loop in a nested Association?

Considering we have an Association: ...
4
votes
1answer
169 views

Arrowheads not quite working as expected

I apologize if this question already has an answer, but my search has yielded no results, and I can't seem to figure out what's wrong with my code, so I thought I'd ask here. I'm using Mathematica 10: ...
4
votes
1answer
75 views

Finding maximal subset of linearly independent functions

I've got a set of functions in one variable. I wish to find the basis of the corresponding spanning set Example: $$\left\{1,\frac{1}{1-\sqrt{x}},\frac{1}{1-x},\frac{\sqrt{x}}{1-x}\right\}$$ may ...
-1
votes
1answer
73 views

The energy released from burning one gallon of gasoline

How can I get this information from Mathematica or Wolfram|Alpha?
0
votes
1answer
197 views

Displaying a bipartite graph in Wolfram Mathematica

Which is the function that can plot me the bipartite graph $K_{7, 2}$ in Mathematica? And after that to delete 2 edges?? Thanks for the help.
6
votes
3answers
218 views

How to prevent ExportString from reencoding diacritics when exporting as JSON

I'm not sure if it's a bug with Mathematica or if I'm missing something, but when trying to ExportString a UTF-8 string with diacritics as JSON, it's messing up the ...
1
vote
1answer
113 views

Understanding `FixedPoint`

I understand that FixedPoint[(# + 2/# )/2 &, 1.] can be written ...
1
vote
0answers
35 views

Fibonacci series up to 300 terms [duplicate]

I tried to generate a list of Fibonacci numbers up to 300 terms and gets a runtime error. f[0]=0; f[1]=1; f[x_]:=f[x-1]+f[x-2]; Table[f[x],{x,1,300}] Is there ...
13
votes
1answer
196 views

CompiledFunctionCall vs. LibraryFunction

When compiling code to C, and the compiled code calls other compiled functions, I see CompiledFunctionCall in the output of ...
4
votes
2answers
194 views

How can export into an .XYZ file using decimals without scientific notation?

I have seen the other posts relating to this however there seems to be more restrictions when exporting to .XYZ. I am pretty new to this but I have been searching for hours. Basically, I have a ...
12
votes
1answer
522 views

Save a C compiled function without losing the blessing of C compiler

Consider the following example: ...
0
votes
2answers
41 views

Multiplying columns of a list of matrices

I have the following list of matrices ...
0
votes
1answer
187 views

Symbolic matrix inversion

If I try to get an inverse of a matrix: a | b | c b | d | 0 c | 0 | 0 Inverse[{{a, b, c}, {b, d, 0}, {c, 0, 0}}] I get the answer: ...
2
votes
2answers
162 views

How do I execute a block of code multiple times? [closed]

Rudimentary pseudoconceptial question: I have a specific block of code that uses random variables and generates a plot at the end based on random code. I want my code to run 10 different times to get ...
21
votes
2answers
264 views
1
vote
1answer
40 views

Can one put event listeners to parts of StandardForm expression?

I have a StandardForm expression Is it possible to add an event listener to the variables, parentheses, and plus signs so that when I click them their color changes for example. Maybe it would be ...
-3
votes
2answers
173 views

Vary the color of a 2D scatter plot [duplicate]

This is what I want. I want to change the colors as I progress through a list.
0
votes
1answer
66 views

Solve and NSolve hitting iteration limit for simple system [closed]

I'm am trying to get Mathematica to determine the intersection of a line and a parabola, like so: Solve[{x + y == 6, x^2 == y}, {x, y}] But evaluating this gives ...
0
votes
3answers
63 views

Simplifying Terms in a Matrix

Given the following 3 matrices: M1=1/3*{{1,1,1},{1,α,α^2},{1,α^2,α]}} Z1={{Z+Zg,Zg,Zg},{Zg,Z+Zg,Zg},{Zg,Zg,Z+Zg}} M2={{1,1,1},{1,α^2,α},{1,α,α^2}} where alpha ...
5
votes
1answer
143 views

Working with quantum mechanics spins

I've written the following code for simple quantum mechanics operators on spin states: It seems to work, but the output could be better - how do I let Mathematics know that $0**\ 0==0$, and can I ...
0
votes
2answers
46 views

Using Nest on a function that takes a function as one of its arguments [closed]

I have a function, nS[f_, xk_], which takes as arguments a function f and a vector xk. It ...
1
vote
0answers
112 views

How can I force the assumption that a symbol is a vector of n zeros

Using $Assumptions = Element[n, Integers] && Element[a, Vectors[n, Reals]] I can assume that a is a n-dimensional vector of Reals. How can I assume that ...
0
votes
1answer
39 views

Replacing y[x] with myPowerSeries

Consider: myPowerSeries = Series[y[x], {x, 0, 3}] Which produces this output. ...
0
votes
1answer
68 views

Why is zero times vector of reals not zero?

Using the following global assumptions $Assumptions = Element[n, Integers] && Element[a, Vectors[n, Reals]] && b == 0 && Element[c, Reals] ...
2
votes
0answers
178 views

How can I launch kernels in series using mathlink

I have written below code to launch n kernels connected to one another in series using mathlinks. Before you read the code allow me to be more precise what i want to achieve: Source kernel(k1) ...
9
votes
4answers
471 views

Difference between Sort and SortBy

I was playing with Sort. All examples I have come across so far, i.e Sort[{1, -1, 3, -3, 2, 5}, Abs[#1]<Abs[#2]&] can expressed in a shorter fashion ...
7
votes
2answers
504 views

Why does PlotRange in DensityPlot have no effect

It looks like DensityPlot and ListDensityPlot automatically clip the plot range to the min and max value of the data, when ...
1
vote
1answer
73 views

Mean of inverse probability distribution does not agree with explicit integral

I tried to work with the inverse exponential distribution and encountered the following, which I think is an inconsistency in Mathematica (version 10.0.2): ...
0
votes
1answer
92 views

Dataset fails on StringMatchQ warning due to Missing value

Missing values are a pain mathematically and computationally in general not just in WL, but I think this problem is more related to Dataset handling of warnings: ...
2
votes
1answer
70 views

Application of Maximize: The cuboid constrained to the ellipsoid in $\mathbb{R}^3$

Since I am a student of Mathematics I enjoy to apply MMA to problems that I have a solid understanding in. The following would be such a problem: Maximize $f: \mathbb{R}^3 \to \mathbb{R}$ given by ...
0
votes
0answers
71 views

Is there a way for me to get Mathematica show its steps? [duplicate]

I have seen similar questions but they were quite dated (3+ years). When performing, say an Integration, it would be beneficial to see the major steps such as variable substitution, change the order ...
6
votes
0answers
171 views

Built-in symbols which are more close to the root/core of Wolfram Language

Seeing the vast scope of science covered by the Wolfram Language (WL) and the large amount of built-in symbols (functions), I am curious to know which built-in symbols are more close to the root of ...
1
vote
3answers
228 views

Rotation of a cylinder around its vertical axis [closed]

I want that that cylinder plotted by RevolutionPlot3D[{Sin[t], Cos[t], u}, {t, 0, 2 Pi}, {u, -10, 0.02}] to rotate around its vertical axis. If possible I want ...
0
votes
1answer
76 views

Using Assumptions in Expressions that Evaluate to be Elliptic Integrals

I have the following integral that I am trying to evaluate in Mathematica: $\int \sqrt{\alpha + m g l \cos(q)} dq$. If $\alpha > m g l$, then the result is a complete elliptic integral of the ...
3
votes
1answer
313 views

Initializing Manipulator value within DialogInput (version 10.1 only)

Bug introduced in 10.1.0 and fixed in 10.2.0 I've confirmed, with WRI, that an issue was introduced in version 10.1 with regard to initializing Manipulator Dynamic ...
1
vote
0answers
44 views

Understanding HoldSequence and ReleaseHoldSequence in Error Handling

I was playing with GeneralUtilities`PrintDefinitions in V10.1, and find some of native Mathematica functions using ...
0
votes
0answers
75 views

BinLists for list of depth greater than 1

BinLists uses the bin specification assuming an interval that is closed on the left and open on the right (according to the documentation). So ...

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