# All Questions

196 views

### Plot with special special gridlines [closed]

I would like to plot a function in plane with axes grid-lines labeled as follows, $1,\sqrt{2},\sqrt{3},\sqrt{4},\sqrt{5},\ldots$, instead of the usual 1, 2, 3, 4, 5, ....
44 views

### Expression evaluation [closed]

I have got the following solution to an equation: ...
131 views

### Solve an eigensystem faster and eliminate Root[…] from the solution

I have a symbolic, 2-parameter, 8x8 matrix to solve, but Mathematica takes something like 20 minutes to solve it and returns a very large output containing expressions of the form ...
70 views

### ListLogLinearPlot with customize Mesh mix up the markers in multiple curve

I have to plot several curves in logarithmic scale. I used ListLogLinearPlot and customized the Mesh option. Then the markers mixed up. ...
186 views

### Memory usage optimization for a large Association/SparseArray

Reformulating my question in simpler terms. Take two lists list1 = RandomInteger[{1, 100000000}, 25000000]; list2 = RandomReal[{1, 10}, 25000000]; Make an ...
16 views

### How to plot y=y[x] from f[x_,y_]=f0 [duplicate]

Given a two-variable function f[x_,y_]:=(*complicated stuff in terms of x and y *) what I want is to do is Plot ...
131 views

### How to simplify and evaluate Integral with lots of DiracDelta dists

I have a question about an Integrals which I can do by hand but I want to implement this Integral in Mathematica. Actually it is the definition of a 2 Particle Phase Space. The Expression is the ...
230 views

### Confirming conservation laws for complex valued functions

Consider the nonlinear Schrödinger equation (I would like to do this for a more complicated set of equations, but to gain understanding I'll consider this simplified case) $$A_t+iA_{xx}+i|A|^2A =0,$$ ...
148 views

### MeshFunction at azimuthal angles for RegionPlot3D

Edit: I said "polar angle"... It should be "Azimuthal angle". Sorry. I want to plot a mesh line at a certain azimuthal angle in RegionPlot3D. My goal is to show ...
47 views

### Integrate and NIntegrate combined, giving MaxPrecision error

I am trying to integrate the following : ...
125 views

### Can I Adjust Thickness of Spheres and Cylinders to Make Objects Printable in 3D?

I have a design of a crystal structure using Sphere and Cylinder in Mathematica. I then exported the result as an STL file and tried to print it. I was told that the objects were "too thin," that ...
38 views

### Why is there a different eigenvector for the same matrix? [duplicate]

I have a matrix that depends on two variables x and y. Matrix[x,y] When I make x=-.25*(1 - 1/3) + .25*(1/3) + .25 y=0 I ...
63 views

### Extracting coefficients of very large polynomials (perhaps by improving Expand or ExpandAll)

Is there a way to improve or bypass Expand (or ExpandAll) for extremely large polynomials? I have a polynomial system of the form $$0 = \sum_n a_n d_{i_1,i_2} \cdots d_{i_{p-1},i_p},$$ in which ...
335 views

### How to iterate over the columns of a Dataset?

I have a Dataset with a simple structure, like this: ...
106 views

### What do RecursionLimit and IterationLimit actually set?

The following recursive functions respectively calculate the length of a Short-cut Collatz Conjecture series and perform a pointless demonstration recursion: ...
437 views

### How do I create a triangulated surface from points?

I have a set of points in a nx3 matrix and I would like to convert them into a surface, so that I may calculate its surface area. The function ListSurfacePlot3D creates the surface how I want it. ...
100 views

### Better to use loop or function when populated list?

In the past I have pretty much stuck to expression building when using Mathematica, but recently I have been writing a procedure to populate an array, which I guess are called "lists" in Mathematica. ...
136 views

### Problems with finding the real solutions of equation

I am trying to find real solutions of equation using Mathematica 8.0 but there is some problem I don't know how to explain. For example, for the input ...
2k views

### Why do Mathematica list indices start at 1? [closed]

In most programming languages, container indices start at 0. This is not random or hardware-related; for example Dijkstra's article explains why zero-based indices make sense. What are the reasons ...
56 views

### Unexpected ReplaceAll behavior with NSolve

I ran into some unexpected behavior using ReplaceAll with an equation of motion using NSolve (or Solve, also). First solving for the initial velocity v0: ...
67 views

### Concatenated rule applications (applying rules to rules correctly)

I am trying to apply a series of individual rules onto an expression sequentially, but also not have to write out the repeated ReplaceAll functions each time I want ...
246 views

### Matrix Plot: How to Apply color function to only a region of the plot

I want to make a matrix plot where a color function is applied to a region of a matrix. Those matrix elements which were not in the region specified should not have any color associated with them, and ...
650 views

### Deleting multiple elements from a list

I have a list with many elements (189) and I want to delete certain elements from it. I have a list of elements I want deleted from it: ...
80 views

### Weird sum regularization? [duplicate]

I noticed some weird behavior in "Dirichlet" regularization of infinite sums. Let us first compute ...
55 views

### How to make autorun stop at the max value?

What should be configured in Manipulate in order to make autorun stop at the max value of a variable and not go back to its initial variable?
60 views

### List command separating multiplicative terms [closed]

I am trying to separate and store additive terms via the List command. For instance I want "AB+CD+XY" to be stored as {AB, CD, XY} This has worked well, but when there is only one term (only ...
74 views

### How to specify positions in a matrix by an array?

If I have an array of sets of points such as pts = {{2,4},{1,3},{5,7}} Is there any super short command to use those pairs to output their respective elements in ...
47 views

### NIntegrate a function containing NDSolve

I am having an issue integrating a function for which I am getting values for when I evaluate it. ...
105 views

### Reshaping list of 2D points by first coordinate

I have a list of (integer) 2d points, and I want to calculate the mean at each point in the first coordinate. So if my data is: ...
786 views

### Finding where two parametric paths cross?

I have been looking through other parametric equations questions and am still unsure where to start with this one. I am given two functions: ...
56 views

### How do I express an equality as a function of one of the equality's variable?

Say I have this equality: (-52271 - 200 x + 100 x^2 - 1058 y + 529 y^2)/52900 == 0 and I want the same equality, but expressed in a function of x, as in y(x). ...
388 views

### DSolve misses a solution of a differential equation

[Note that in the cited duplicate, DSolve not finding solution I expected, the general solution returned by DSolve is missing a solution for quite different reasons ...
82 views

### Should I Remove the initial symbols of Module?

Often we use Module to construct complicate function. Consider that Module create new vars every time we run the function, should I remove the initial values at the end of Module-function?Or should I ...
135 views

### Extract all Values from nested Association

Considering we have an Association: ...
54 views

### NumberLinePlot issue depending on number of elements being plotted

When evaluating this: Table[n -> NumberLinePlot[{Range[n], Range[n]+.1}], {n, 4}] we get this output: Why is it different for n=2? Looks like a bug to me. ...
44 views

### Inconsistent font rendering when using a remote kernel on a different OS

I have a Mathematica 10.0 on Linux and one on OSX. I'm using the OSX as a remote kernel. During parallel computation, if I render some graphics, the fonts and axes are not rendered the same way ...
97 views

### How do I solve this ODE numerically in Mathematica?

I want to solve these equations numerically in Mathematica and plot them. $$u'(t)=1.5\,u(t)\,v(t)-u(t) \space \space \space \text{and} \space \space u(0)=0.001$$ \begin{...
361 views

### Alternative to Subsets to generate k-combinations

I need to generare a huge number of k-combinations for a quite big set of numbers (more than 100), so I would avoid Subsets because it requires too much memory (it generates all subsets at once). I ...
217 views

### How do I add my own help pages to the in-built Wolfram documentation?

How do I add my own help pages to the in-built Wolfram documentation ?
114 views

### ListPlot with checkboxes [duplicate]

I have imported data for several projects {prj1, prj2, ...} from an excel file, in form of {x,y} coordinates of points. I stored these data in variables and I would like to plot them, also having the ...
314 views

### How to combine Date and Time objects into DateTime object?

Considering a DateObject d and TimeObject t: ...
202 views

### Slider with initial value on manipulate [duplicate]

Consider this simple code Manipulate[n, {{n, 3}, 1, 5, 1}] It will produce If we click on Show-Animation-Controls button next to the slider, suddenly the ...
94 views

### Floating highlighting bug [duplicate]

Bug introduced in 10.0 and not fixed up to 10.2 At some random point in time the highlighting does not disappear any more. By highlighting I mean transparent boxes appearing for find feature ...
228 views

### DFT: why are frequencies mirrored around the frequency axis?

I want to apply Mathematica's DFT procedure, Fourier[], to a Gaussian. Why a Gaussian? Because I know the analytical result. So I define ...
142 views

### How can I use sequence in plotting domain?

I would like to plot a function but have a domain defined elsewhere as follows: xrange = Sequence[0, 2π]; Plot[Sin[x], {x, xrange}] However, this doesn't work ...
429 views

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1k views

### I need F(x,y) = xy (not x*y) e.g. x= 1, y =2 so F(x,y) = 12 [closed]

I just need F(x,y) that give me e.g. x= 1, y =2 so F(x,y) = 12 Is that possible. I tried Google but not able to find a ...
83 views

### Solving differential equation but keeping showing running

I am trying to solve this differential equation, see the command below. But the cell keeps showing that it is running without giving any answer for a very long time. Eventually I had to abort it. Does ...