6
votes
5answers
3k views

Specifying the size of open circle PlotMarkers in ListPlot

I would like to use ListPlot to plot some points. I would like the PlotMarkers to be open circles. I can use ...
6
votes
6answers
540 views

How can I merge two lists in a special way?

It's been over a year since I've used Mathematica, and I'm having a total brain fart on a home project. I'd like to take an existing list of lists, say, ...
6
votes
1answer
534 views

Using the symbol I for electrical current [duplicate]

I would like to use the I as a symbol for the electrical current. How can I redefine it, so it is not interpreted as the imaginary unity?
6
votes
2answers
2k views

Log-Plots and PlotRange

Why does the PlotRange option in ...
6
votes
1answer
615 views

Evaluate continued fraction

Mathematica has the ContinuedFraction[] function to give the continued fraction expansion of a rational (or approximation of a real) number. I'm interested in the ...
6
votes
3answers
818 views

Graph adjacency matrix with unconnected nodes

I am trying to display a series of 9x9 adjacency matrices which represent directed graphs on a 3x3 grid. The issue I am running up against is this (compounded by that fact that I don't really know how ...
6
votes
1answer
191 views

How to reduce expressions with complex coefficients in the form of a+0.*I

I'm trying to get an eigenvalue equation in Mathematica, and the result is an expression with coefficients of the form a + 0. I. For example, Is there any clever ...
6
votes
1answer
339 views

Check homework integration in Mathematica

Given in my homework I have to compute (by hand) $$\iint\limits_{x^2+y^2\leq 1}(x^2+y^2)\,\mathrm dx\,\,\mathrm dy.$$ My solution so far: Let $f(x,y)=x^2+y^2$ and $K=\{(x,y)\in\mathbb{R}^2:x^2+y^2\leq ...
6
votes
4answers
1k views

How do I plot a function over a subset of the displayed interval?

I want to plot f1[x] over 0 < x < L/2 and f2[x] over ...
6
votes
2answers
481 views

Starting NDSolve from intermediate time step?

I always wondered if I could start NDSolve from an intermediate time step. What I mean is, in the code sample below, if I were to run my solution from ...
6
votes
1answer
464 views

Using physical dimensions in Mathematica DSolve

I would like to calculate a system of two differential equations in Mathematica using DSolve, like: ...
5
votes
3answers
153 views

How to efficiently get breakpoints of piecewise continuous functions

Setting. Imagine that we have several arbitrary linear functions in 2D that can be changed manually (say, slopes are parameters). Their Min (or ...
5
votes
3answers
225 views

Derivative of contour in ContourPlot

Sorry to bring this question up again, since there are many similar questions on the site. I use to think this is a easy job to do, because for the worst case I can follow the answers on this site. ...
5
votes
6answers
629 views

Can Mathematica delete some of the 0's from a list?

I have a list: {1,2,3,0,0,4,5,0,0,0}. I want to delete the 0's occurring after the last positive integer. In other words, I ...
5
votes
3answers
717 views

Complex conjugate

How do I complex conjugate a vector? ...
5
votes
1answer
175 views

Slow exponential evaluation over lists

This question,which is still unanswered, might be relevant because it involves NIntegrate over lists and it also has Exp. In ...
5
votes
1answer
90 views

Specifying WorkingPrecision in LogLogPlot produces invalid plots [duplicate]

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 ...
5
votes
0answers
192 views

Mathematica can't export $\sqrt{}$ [duplicate]

Fixed in version 10.1.0 It looks like version 10 can't export to pdf correctly with square root. For example: ...
5
votes
1answer
122 views

How to “undo” SetOptions (restore defaults)

Say I had some good reason to use, for example SetOptions[Plot,ImageSize->500, LabelStyle->OutrageousPink]; But now sometime has passed, life has changed, ...
5
votes
3answers
463 views

How to generate a chirped signal

As there is no ChirpSignal function in Mathematica, can anyone tell me how to write a custom function to generate a sinusoid with a frequency that changes ...
5
votes
2answers
341 views

Exporting row vector as a column in excel

I want to export a vector in Mathematica to appear as a column in Excel. I am trying A={1, 2, 3}; Export["mfile.xls", {"A" -> A}] But it is showing 1,2,3 in ...
5
votes
1answer
207 views

How to plot the result of this singular integral?

Please I open a new post here after this one : http://mathematica.stackexchange.com/a/59203/10158 Now I want to plot the function $f(a,b)$ as a function of $b$ for different values of $a$ : $a=0.5$ , ...
5
votes
1answer
138 views

How to make a case insensitive sorted list and rename the file names of a given folder?

Suppose I had about 500 .JPG and .jpg files in my folder "c:\images\". How to ask ...
5
votes
0answers
217 views

Citation of the algorithms used in FindGraphCommunities

For my research work I need to put a comparison of different community detection algorithms. Instead of implementing all those algorithms once again, I would like to use the methods already provided ...
5
votes
2answers
320 views

Why doesn't Roots work on a certain quartic polynomial equation?

In everything that follows I am using Roots to get the solutions to the equations. I start off with this equation: $$ \frac{A}{3}x^4 - x^2 + 2ax - b^2 = 0$$ Now ...
5
votes
2answers
117 views

Comparison Operation for Nested Matrices

I have a nested matrix n as bellow ...
5
votes
1answer
170 views

When to use indexed variables

Still learning the fundamentals of the language I would like to ask you what advantages there might be in writing something like: a[1] = 2; a[2] = 4; a[3] = "x"; ...
5
votes
1answer
477 views
5
votes
0answers
126 views

Is there a package or canonical way for writing test harnesses in Mathematica?

I've written a complicated function foo.1 I'd now like to simplify this function's code, and later enhance it with more features. With each change, however, I'd ...
5
votes
0answers
1k views

Import Large Excel File

Currently, I am working on a large time series dataset, which contains 928,586 rows and 35 time intervals in columns, in excel format (.xlsx) and using Import to ...
5
votes
1answer
163 views

Omitting singularities from plot by specifying them in range

See the Mathematica 'basic plotting' documentation: http://reference.wolfram.com/mathematica/tutorial/BasicPlotting.html Scroll down to the third plot on that page, which says the following: "The ...
5
votes
2answers
291 views

Package relative file path specification

I have some packages inside a folder (named Packs) that is in the same file level of some executed package. ...
5
votes
1answer
193 views

Manipulate keeps updating due to a function

Edit: This is apparently only a problem on a mac running OSX. I am trying to use the 'stretchText' function by Jens. But when I use it in manipulate, the output keeps updating without changing ...
5
votes
1answer
499 views

Why is parallel slower?

I always assumed that distributing a computation is faster, but it isn't necessarily true. When I do Sum[i,{i,10^4}] I retrieve an answer much faster then if I do ...
5
votes
0answers
532 views

ItoProcess for stochastic reaction-diffusion equation

I am trying to simulate a stochastic differential equation in time and space, but I'm unsure if this can be done in Mathematica. The sde that I would like to study is: $$ ...
5
votes
2answers
266 views

Better method for creating a tuple out of two lists

I just combined two lists using this method ...
5
votes
2answers
5k views

How do I make a 3DPlot using cylindrical coordinates?

I'm trying to plot a function of the form $z(r,\theta)$ where $r \in [0, R]$ for a finite R, $\theta \in [0,2\pi[$, and z is the third coordinate, a function of the first two. I couldn't find anything ...
5
votes
1answer
161 views

How do I avoid the gaps introduced by a frame on a plot?

You can see that there are gaps on all sides of the plot between the frame and the extent of the line that I've plotted. How do I get rid of these? I'd like the frame to cover $[0,1]\times[0,1]$ and ...
5
votes
3answers
564 views

How to sum matrix elements based on finding the first (and second) non-zero elements of each row?

I have a matrix: I would like to sum all the first non-zero elements of each row so that I get a value of $$25.5317 + 8.85471 + 6.90018 + 32.9436 + ... $$ and so on and simply ignore zero rows. ...
5
votes
1answer
820 views

How do I reverse the axis in ParametricPlot?

In astronomy, right ascension is usually plotted with positive values that increase from right to left. I have seen discussions of successful and unsuccessful attempts to reverse the order of an axis ...
5
votes
3answers
314 views

How to force Dt[ ] to recognize dependencies

I want to differentiate a function f[] for which I don't have a specific expression. f[] depends on ...
5
votes
2answers
232 views

Pattern matching deletion of list items [duplicate]

Possible Duplicate: How can I remove B -> A from a list if A -> B is in the list? I'm working toward building a graph and use some code to construct my rules which results in a form ...
5
votes
2answers
593 views

Add elements in a sublist

I have created a subset of arrays: ...
5
votes
3answers
596 views

Smooth/histogram a 2D set

I have a 2D dataset like this one: {{x1,y1}, {x2,y2},...} I need to smooth/histogram the data in such a way that binning is over the x-coordinate, while ...
5
votes
1answer
233 views

Why does the Front End group backslashes into pairs?

What is \\ for? Help finds nothing on it. An odd number of backslashes greater than one are grouped by two and the last one is displayed with a different color. ...
5
votes
2answers
361 views

Plotting contours of a function for different values of a parameter

I want to draw a picture of $(x-t)^2 + (y-t^2)^2 - t^2$ in $xy$ plane, with different values of $t$. I did it in a very silly way , namely, ...
5
votes
4answers
591 views

How to repeatedly show variations on a plot

I would like to show graphics repeatedly with changes in parameters. Neither of the following show anything. Nor do they give an error message. ...
5
votes
3answers
2k views
4
votes
2answers
90 views

Factor out the scalar multiplier for the dot product of 2x2 matrices

If yy and zz are 2x2 Hermitian matrices, is there a way that I can mark them (with a property?) as Hermitian so that Mathematica can assume that it can factor out and simplify scalar multipliers from ...
4
votes
2answers
118 views

Custom fonts show as boxes when opening Mathematica-made PDFs with Illustrator

If I export a PDF from Mathematica, then open it with Illustrator, the font glyphs will sometimes appear as boxes, depending on what font was used. Why does this happen? Is there a workaround? I ...

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