2
votes
1answer
88 views

How to plot on complex plane with Mandelbrot set

I essentially want to treat the Mandelbrot set plot as a normal plot so that I can plot arrows and points on top of it. This is what I want to do but it gives me an error: ...
1
vote
0answers
75 views

Simplifying $e^x>1$, is this a bug?

Simplify[Exp[x] > 1, x ∈ Reals] results in no simplification, although Reduce[Exp[x] > 1, x, Reals] correctly ...
2
votes
2answers
81 views

How to change the font color and size of tick labels by default

I've read Mike Honeychurch's answer here, and while it tells me how to change the font size on all of my plots, that size change affects (I think) all text on the plot. I would like to be able to make ...
1
vote
1answer
49 views

Are all of the numbers in my file legitimate hex numbers

I have about 10,000 hexadecimal numbers (32 digits each) in an excel file, in one column. I want to verify that all of them are indeed hexadecimal number and that no other characters are present. My ...
0
votes
1answer
59 views

Differential equations DSolve constant issue

After using DSolve to a set of differential equations, three constants arise. They are C[1], C[2] and C[21]. I have checked thoroughly that there are no C[3], C[4],....C[20]. It is quite mysterious to ...
1
vote
1answer
43 views

Strange Issue with RowBox

Can someone explain why this notebook [RANGEWORKING.nb] ...
3
votes
1answer
62 views

Output function control and manipulation for efficient computation

I have taken note of a similar post related to modifying function parameters. I tried to adapt Kuba's solution to this post but I can't get it to work. I will illustrate my problem using a similar ...
1
vote
1answer
103 views

Show plot legends for multiple curves in one plot [closed]

I have 5 curves, figure1a0, figure1a001, figure1a01, figure1ae01, and figure1ae001,. I display all these curves in one plot with Show. I want to give a label to ...
2
votes
0answers
51 views

WSTP (formerly MathLink) problem

I recently set about to re-compile some old (2008-2009) applications that use MathLink in preparation for creating new, modified versions. Mathlink has been deprecated but WSTP seems like a fairly ...
13
votes
1answer
656 views

Is Mathematica `ContourPlot` function really so efficient?

I wanted to find the roots of the function $f(x,y)=\sin(3.2x)\sin(1.3y)-2.1 \sin(1.3x)\sin(3.2y)$. This is what the function looks like: ...
0
votes
0answers
20 views

Tricks to speeding up optimisation of a function involving a heavy integration

This is the code, and energycoeffs[] is the function that takes in a dxd matrix and spits out a scalar value. ...
0
votes
0answers
25 views

How to evaluate NMinimize inside a function

I want to define a function that returns a sum of differences of some points to a given function. To obtain these differences I would like to use NMinimize, but if I implement that straightforwardly, ...
0
votes
1answer
24 views

Why Table is not giving me the same sequence for eigenvalues of matrix

Let consider a matrix and evaluate the time dependent eigenvalues M[t_]:={{Sin[t],Cos[t]},{t,t*t}}; e1[t_]:= Eigenvalues[M[t]] Now If I evaluate ...
0
votes
2answers
57 views

Convolution of a piecewise function

I want to find the convolute the the functions in the Convolve command ...
1
vote
1answer
40 views

Error with using SortBy in a Map [closed]

I have a data set in the following format: SomeData = {{a, 1, 2}, {b, 2, 3}, {c, 3, 4}, {b, 1, 9}, {c, 1, 10}, {a, 2, 3}, {a, 3, 8}, {b, 3, 4}, {c, 2, 9}}; The ...
3
votes
0answers
56 views

Efficient image stacking

I have a list of lists of images that I would like to stack and create mean images for each list of images. Images are .jpg files 2592x1944 pixels large. Each list ...
0
votes
1answer
37 views

Vector Analysis in Version 8

Silly question. Why does Needs["VectorAnalysis`"] Grad[Sin[x^2 + y^2], {x, y}] give the error Coordinates::invalid: "{x,y} is not a valid coordinate system ...
3
votes
0answers
45 views

WorkingPrecision in LogLogPlot creates wrong plots

I seem to have found a bug with LogLogPlot in version 10. If I specify a working precision, the function produces total garbage. Here is a simple example. The first case, without WorkingPrecision ...
5
votes
2answers
157 views

Drawing a path which realises the diameter of the graph

So I enter a (0,1) adjacency matrix and I get the following graph: The diameter of this graph is 4. How can I ask that two vertices which realise this diameter be drawn with different filling ...
1
vote
1answer
58 views

How to impose normalization condition (not initial condition) on DSolve or NDSolve?

I have a set of differential equations (or DAEs): $\begin{cases} 5x_{2} + 3x_{4} + 3x_{5} = \frac{dx_{1}}{dt}\\ 5x_{1} + 5x_{2} + 5x_{3} + 3x_{4} + x_{5}= 0\\ 3x_{2} + 3x_{4} + 10x_{5} = ...
1
vote
0answers
37 views

Is it possible to circumvent this overflow?

I'm trying to evaluate the following function numerically: $ f(A,B)=\frac{2A\pi ^{5/2} (-1)^B}{(A!)^2B!} \, _4\tilde{F}_3\left({\frac{1}{2},1-A,1-A,1-B\atop ...
1
vote
1answer
67 views

How can I copy & paste cell styles?

In Mac's mail app the key shortcut "command + option + c" gives a copy selected text style and "cmd + opt + v" pastes the style. Is there a way to achieve this with cell styles? The keyboard part is ...
5
votes
2answers
212 views

Evaluating complicated trig without resorting to numerical methods

I have an angle theta given by Kx = (2/Sqrt[3]) ArcSin[Sqrt[3/10]]; Ky = (2/3) (ArcCos[(1/5) Sqrt[7/10]] - Pi); theta = Cos[ArcTan[Kx, Ky]]; This evaluates, by ...
0
votes
0answers
17 views

Error Using Mysql In Mathematica

I'm using Mathematica, and accessing mysql through mysql (Connector/J). When I try to update a field in my table using WHERE statement, all the rows get updated ...
6
votes
1answer
90 views

Context of localised (dynamic) symbols

When you localise a symbol with Module, the created unique symbol is usually in the current context. There seems to be an exception to this which has further ...
2
votes
1answer
34 views

Plotting Vectors in Mathematic at lat/long positions

I have some current data that I want to plot in Mathematica. The first two columns are the latitude and longitude respectively (longitudes are negative b/c it is west of the prime meridian and all ...
2
votes
3answers
97 views

Plot a table of lists

I want to make a point plot of a table with lists in it. Assume I have data like this: data={{1,2,3,4},{5,6},{1,5},{2,4}}; and now I want to make a point plot ...
0
votes
0answers
44 views

How to make Show work in Mathematica 10 Kernel

Wolfram Research says it no longer supports JavaGraphics in Mathmatica 10. This is very bad for people who prefer the Kernel to the FrontEnd. However, I am still able to get it to work. Show ...
0
votes
2answers
43 views

Table results within loops

I have the following code. ...
0
votes
1answer
27 views

Derivative inside a Series [closed]

I have a function defined by a sum, which I would like to differentiate. For example: ...
0
votes
0answers
55 views

How to filter my signal?

As you can see, my signal is superimposed by an other sinus which has a slightly longer frequency. I would like to filter this out. I think I can do the filtering process, but there is one step that I ...
-1
votes
1answer
46 views

How to assign variables to selected roots of a polynomial equation? [closed]

I have a polynomial equation like the below, and I want to assign variables to the roots that are not pure imaginary. How I can do this? ...
12
votes
3answers
1k views

Can Mathematica's random number generation be improved?

Performance on Random Number generation is intolerable. Whenever you need many deviates from the same distribution but with different parameters it takes forever. Here is a thread on Poisson ...
1
vote
2answers
62 views

Solving equations using algebra [duplicate]

Has anyone ever solved an equation for students using algebraic steps? For example, you start with the equation. 2x+3 = 5 Then you show subtracting 3 from both ...
2
votes
1answer
41 views

How do I change the size of an imported picture in an animation?

My code right now plots a function, and animates an image moving along the curve of the function. I want to reduce the size of the image for this animation but I can't figure out how. If I try to ...
3
votes
1answer
51 views

Pattern matching multiple symbols names and powers

Seemingly a relatively simple problem, I can't seem to find a solution... I want to build a pattern that will match any symbol whose name starts with V, and is elevated at any power. Something on the ...
2
votes
0answers
36 views

Precision loss in FourierDCT

I have high precision data that I want to do Fourier transform with, but it looks like the precision is lost dramatically. ...
0
votes
1answer
59 views

Integrating spherical harmonics

I am trying to simply check the integration/normalization condition on the SperhicalHarmonic functions that are built into Mathematica. So basically, I just want to check that the following integral ...
3
votes
2answers
64 views

Problem with ParametricNDSolve

i have a strange problem with ParametricNDSolve. Given the sistem of differential euqations ...
0
votes
1answer
31 views

Numerical error in DSolve [duplicate]

I'm solving the 1D Poisson equation and am getting some funky numerical artifacts in the solution. ...
4
votes
1answer
64 views

EasterSunday replacement in Mathematica 10

The Calendar package, now obsolete, had functionality for "special dates", in particular EasterSunday[]. The documentation says it's been subsumed into Wolfram ...
3
votes
1answer
67 views

While stops running in a Dynamicmodule

I made this: ...
0
votes
1answer
27 views

How to get array/list of results of RotationMatrix?

For most other functions, passing in a list of arguments will return a list of results. E.g. t = Range[0, 10]; m = N[Sin[t]] returns ...
0
votes
0answers
36 views

Using ImageCompose with Large Images

I am trying to use ImageCompose to overlay large images. The images are too large to manipulate in memory. I am familiar with ImageFileApply and ImageFileFilter to work with images on disk, but I do ...
2
votes
2answers
101 views

How to plot points with error circles on map with latitude/longitude grid

I am currently working on a project to model the location of icebergs in the northwest atlantic. When an iceberg is sighted, an error circle is plotted around it (with a bivariate normal probability ...
4
votes
2answers
88 views

Can I modify Ctrl— to insert Indexed expressions?

For me, Indexed[x, n] is a much more useful and versatile construct than Subscript[x, n]. I would therefore like to modify ...
0
votes
0answers
12 views

why does a ReplaceAll stop Plot from cycling colors? [duplicate]

Suppose I Plot[{a x^2, a x^3} /. {a -> 2}, {x, 0, 1}]. Then the expressions plot, but the colors do not cycle. If I Evaluate ...
1
vote
1answer
48 views

How to evaluate some parts of an expression inside Hold? [duplicate]

I want to return a Hold expression but with some parts pre-evaluated. The easiest way to explain this is probably through code example. Here is what I have ...
3
votes
2answers
53 views

How do I apply a ColorDataFunction[] to a grayscale image? [duplicate]

Suppose I have a 2D array im of real values between 0 and 1, representing a grayscale image. I can turn im into an image very ...
0
votes
0answers
17 views

What are the limits to file size for Import[ file.wav,“WAV”]

What is the maximum size *.WAV file that can be imported into Mathematica with Import[]?? What is the code used to read the header of a *.WAV file?

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