# All Questions

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 = ...
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 ...
180 views

I have this: ...
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 ...
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 ...
97 views

### Dynamics and Block interfere

As mentioned by Albert Retey in a comment, we can unintentionally interfere with our dynamics as follows ...
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 ...
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 ...
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. ...
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 ...
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 ...
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 ...
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! ...
107 views

### How to loop in a nested Association?

Considering we have an Association: ...
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: ...
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 ...
73 views

### The energy released from burning one gallon of gasoline

How can I get this information from Mathematica or Wolfram|Alpha?
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.
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 ...
113 views

### Understanding FixedPoint

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

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

Consider the following example: ...
41 views

### Multiplying columns of a list of matrices

I have the following list of matrices ...
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: ...
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 ...
264 views

Observe: ...
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### 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 ...
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.
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 ...
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 ...
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 ...
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 ...
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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) ...
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 ...
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 ...
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): ...
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: ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...