# All Questions

202 views

### Real-like jet engine flame

I’m trying to make rocket flame and jet engine fire of all kinds that is an 3Graphics object so that it can be used with a 3D rocket project. But I can’t get the basic translucent effect right. ...
72 views

### How can Map be given access to the keys of a Dataset?

Consider an example Dataset: ...
64 views

### Increase Precision in Numerical Integration

I need to generate a table of Chebyshev expansion coefficients of trigonometric functions (in this case Cos[2 Pi t] to very high accuracy. Code is: ...
41 views

### Different kind of numeric erros when plotting recursive functions

I have been trying to plot some numeric solutions to a Hamiltonian system. Basically I have ...
158 views

### Best fit equation from a scanned image

I am trying to extract a curve from a scanned graph and find a best fit equation. For example, starting from: How could one find an equation starting from the image file ?
56 views

### Consecutive integers that can be written as the product of three distinct primes

Mathematica novice here. I want to start with a list of integers that are the product of three distinct primes m,n, and o, where 2 <= m|n|o < 2000. ...
171 views

### ParametricNDSolve and plotting problem

I have a problem with ParametricNDSolve: ...
164 views

### Adding walls to a region plot

I've done this code: Plot3D[x + y + 1, {x, 0, 1}, {y, 0, 1}, RegionFunction -> Function[{x, y, z}, 0 <= y <= Sqrt[x]]] Producing this image: In ...
93 views

### Distance between vectors does not match distance between probability distribution [closed]

I have vectors that describe shapes. I am doing Euclidian distance between vectors to get the similar shapes and I get a good results of all classes. Theoretically, two similar shapes (shapes in a ...
38 views

I wrote: ...
81 views

### NDSolve inside Module with local variables

I want to use NDSolve within a Module and output the solution at some times. (Mathematica 10) All works fine with global variables (symbols) ...
227 views

### Is there a way to control V10's undo length?

This may be a duplicate (if so I will remove this), but I was having trouble finding the relevant bit of documentation to fix it. I noticed that my FrontEnd memory ...
65 views

### How to make Import recognize a new file extension? [duplicate]

I've written an import converter for a custom file format, and it all seems to be working as expected, except for the fallback behavior with no arguments: ...
287 views

### Integrate over piecewise function defined using /;

f[x_] := x /; x<0 f[x_] := x^2 /; x>=0 Integrate[f[x],{x,-1,1}] The above does not work (Mathematica returns it unevaluated), but the below does. ...
89 views

### solve recursive factorial function [closed]

Is there a way to solve this recursive factorial function? a[n + 1] = (n+1)*a[n], a[10]=10 I am looking for the value of a[n] ...
83 views

### Dynamic and Refresh

If I am not mislead by my memory, in Mathematica 6 a function Refresh was introduced, having the options UpdateInterval and ...
154 views

### Finding roots of transcendental equation

I need to find the roots of the transcendental equation (eq. 7). I came up with the following command, where exp1 is the integrand appearing in eq. 9, and exp2 is the complete expression of eq.7. ...
493 views

### Efficient Indexed Sort

Suppose I have a preference for animals given by: orderOfAnimals = {"dogs", "cats", "fish", "elephants", "giraffe", "hamsters", "poodles"}; I'm given many data ...
132 views

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250 views

### Combining Gravity Turn and Orbit Models

I have a mathematical model for the motion of an orbiting spacecraft about Earth: ...
68 views

### Defining a function that prints both the name and value of a variable defined locally within the calling function

To save time when debugging with Print statements, I'd like to define a function -- call it PrintVal -- that prints both the name and value of a variable defined locally within the calling function. ...
121 views

### How can I use legend in ContourPlot3D and add arrowheads for axis?

I am using ContourPlot3D to show two surfaces. This is my code. Now I want to use Legend to distinguish the two surfaces, and add arrowhead for the three axis. ...
38 views

### Plot command uses same colors when applying pattern on list [duplicate]

When I do Plot[{fun1,fun2} ./ val1->1,{t,0,10}] then both plots are in the same color! If I use instead ...
61 views

### Would you give me some advice on Elliott's equation?

I'm trying to solve below equation on mathematica for plotting, but I'm a complete beginner. ...
67 views

### How large can be the dimension of a complex matrix which Mathematica can handle to find its eigenalues?

I have been working with 12 cross 12 complex matrix in Mathematica , I need to work with bigger size matrix of the dimension of the order of hundreds , I was wondering if Mathematica can handle ...
95 views

### How to express “if any component in a vector satisfies that …” in Mathematica

For example, l is a list of vectors. I need to delete from l all the vectors with any component larger than 1. How should I do ...
26 views

### MapThread with incompatible length (How to Map twice in the same line)

l and b are two lists of vectors with different length. I need the list of vectors that is constructed by adding each member of ...
93 views

### Removing all values from a list that satisfy a given condition

Suppose I have a list, list = Table[{n}, {n, 1, 5}] (* list = {{1},{2},{3},{4},{5}} *) and I want to remove all values from this list that are greater than 3, so ...
109 views

### Creating a list of lists as a function of a list

I have a list of length n whose elements are all 1 and -1. For each -1 in the list i want to create a list with a -1 in the same spot and a 1 everywhere else. For example: A list like {-1, -1, 1} ...
45 views

### What are the possible values of sub-options for Classify[]?

Specifically, how can I find the possible values of sub-option "KernelType" of option "Method" for Classify? Here's an example: ...
90 views

### What does the expression “Total[funca[a,#] & /@ #] & /@ {x,y}” possibly mean?

Can the expression be simplified as "Total[funca[a,#]] & /@ {x,y}"? What does the double of "& /@" mean? Where can I find some reference? Updated According to Mr.Wizard's answer, I now know ...
184 views

### Glitch in Filling?

Bug introduced in 8.0 and persisting through 10.0.2 or later I ran into a problem while plotting and I was able to narrow it to this. Before I start "spelunking" I'd like to know if I am ...
62 views

### Symbolic and numeric calculations (and plots) simultanuosly

I use Mathematica to do a bunch of symbolic calculations (integrals, ...). This is good because I found that sometimes, if I plug in numeric values, Mathematica takes much longer. However, sometimes ...
49 views

### How to replicate v9's color conversion to LAB under v10

Mathematica 10(.0.0) appears to use a different flavor of the LAB color space, but I would like to emulate the same behavior observed in version 9(.0.0). v9 ...
31 views

### How to set all the numerical values as double

Is it possible to set the accuracy of every numerical value and the result of every computation to double like in Matlab? I want Mathematica to use just 3 or 4 ...
60 views

### Error: in the part assignment is not a symbol [duplicate]

I am trying to set part of a Doubly-indexed list aInitialPopulation to cNumHeg. Specifically I am trying to set the 3rd part of the list aInitialPopulatiom[[cNodeNumber]] to cNumHeg. My (attempted) ...
91 views

### Compact Map of USA with Alaska and Hawaii shown under California

Is there a more efficient way to include Alaska and Hawaii on a compact US map than the combination of the three GeoGraphics with Insets shown below? ...
91 views

### Root finding: zeroes of Mathieu function

I am finding the roots of the Mathieu sine function, and find Mathematica and Maple do not agree on the solutions. For example, consider the solutions of Abs[MathieuS[4x, 4, Pi]] = 0, for 2 < x ...
120 views

### Distributing identifiers

I have a list that looks like this: {{"a",},{2010,0},{2011,10},{2012,27},{"b",},{2011,11},{2012,66},{"c",},{2010,19},{2011,20},{2012,}} I want to turn it into: ...
47 views

### How to control factor gathering in Simplify

To make my results more readable, I need to make MMA gather terms differently. In this example, Simplify gathers terms by common z[]: ...
171 views

### What is the shortest way to switch between heads of nested functions

consider this example: f[g[x]] what is the shortest way to switch between heads of nested functions to produce. g[f[x]]
48 views

### Error associated with parameters in Minimize (or NMinimize) in discrete fitting

my problem goes as follows: I need to a discrete fit of a discrete function. Say I have the following made up data points, which are generated by the parabola ...
127 views

### FontSize problematic when used in LabelStyle

Bug introduced in 9.0.0 and persisting through 10.0.2 or later Consider the following few examples, each producing a trivial graphic object: ...
61 views

### What are the applications of using functions whose heads are also functions?

I noticed that it is possible to construct something like f[x][y]. Displaying this in TreeForm indicates that this expression ...
64 views

### Finding duplicates in a list

I have a list of integer, and I want to know if the list contains any duplicates. My code is working, but I feel there is a more straightforward way of doing this ...
66 views

### Changing the size of arrows in a directed graph?

How can I change the size of arrows in a directed graph? By default, the arrows are too big and clutter the graph.
120 views

### Plotting 3D arrows on a surface

I have a cone: ...
68 views

### Using Animate/ListPointPlot3D on more than one list

I have a couple orbits defined which have been mapped into one array as shown: ...