5
votes
3answers
221 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
618 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
1answer
170 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
88 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
1answer
113 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
449 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
333 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
137 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
213 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
3answers
143 views

Why does TraditionalForm[Inactivate[x y]] show x * y ? instead of x y?

Given that both x and y are expressions, in my case x is ...
5
votes
2answers
117 views

Comparison Operation for Nested Matrices

I have a nested matrix n as bellow ...
5
votes
1answer
167 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
441 views
5
votes
0answers
125 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
157 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
289 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
191 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
488 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
524 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
908 views

Using ChemicalData to make molecule graphics

$\require{mhchem}$I would like to take the acetone $\cf{((CH3)2CO)}$ and chloroform $\cf{(HCCl_3)}$ molecules that Mathematica's chemical data provides, and plot them together. I want to show how ...
5
votes
2answers
265 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
158 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
563 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
805 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
312 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
587 views

Add elements in a sublist

I have created a subset of arrays: ...
5
votes
1answer
232 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
355 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
586 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
89 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
134 views

FEM giving “ … is not a polynomial error”

Executing the program below I get the ... is not a polynomial error message. I don't have an idea why I am getting this -- any suggestions? ...
4
votes
2answers
151 views

Parametrize a circle as a tube?

I have this code: ...
4
votes
1answer
188 views

VertexRenderingFunction (or EdgeRenderingFunction) with movable nodes?

In GraphPlot, I'd like to use VertexRenderingFunction (VRF) and have the resulting object behave the same way under dragging verticies as it does when I do not use VRF. The same issue occurs for ...
4
votes
1answer
121 views

ControlType -> None Vs. Module inside Manipulate (i.e. making everything local)

I'm building a program on another one made available in the Wolfram Demonstration Project. I've noticed that in the original code (working flawlessly) many variables were made local inside the ...
4
votes
3answers
146 views

Getting terms and only evaluate specific parts

I want to expand the expression but I do not want it to evaluate. Sum[(HoldForm[1/(2 # - 1) - 1/(2 # + 1)] &)[i], {i, 1, 6}] However if you evaluate this you ...
4
votes
1answer
164 views

Intelligent vertex placement in large tree graphs

This question about graph layout is fairly general, but can be illustrated in the case of the Collatz Conjecture. Collatz created the following function over integers greater than 1: If the integer ...
4
votes
2answers
137 views

Headings, subheadings, text cells etc and Alt+n

This is a minor point but annoying. I have just upgraded to version 10.0.2.0 and discovered that you must select a bracket before doing Alt+1, or Alt +7 to make a cell a heading or text cell. This was ...
4
votes
1answer
105 views

Filtering Query Nested Data (Dataset and Association)

I am trying to filter a nested Dataset. I have some data that looks like this (curated for this example): ...
4
votes
3answers
209 views

Transform an InterpolatingFunction

I'd like to transform an InterpolatingFunction from NDSolve but can't figure out how. Here's an example. The equation I want to solve is ...
4
votes
2answers
196 views

Manipulate in Manipulate

Question 63982 (Altering values in Manipulate with dynamically generated controls) got a very interesting answer from @belisarius, in which he used a Manipulate ...
4
votes
5answers
341 views

Sequence generation

If I wanted to generate a sequence that follows the pattern $$x_{n}=x_{n-1}+\dfrac{1}{2}\left(\sqrt{1-y_{n-1}\ ^{2}}-x_{n-1}\right)\\ y_{n}=y_{n-1}+\dfrac{1}{2}\left(\sqrt{1-x_{n}\ ...
4
votes
8answers
431 views

How to sort my list?

For example I have two lists of such structure L1 = {{"Australia",a1}, {"USA",a2}, {"Norway",a3},...} L2 = {{"Russia",b1}, {"Norway",b2}, {"Japan",b3},...} I ...
4
votes
3answers
316 views

How to solve an integral equation by iteration method? [duplicate]

How I can obtain $n^{th}$ approximation of the following equation $f(t)=t+\int_0^tds f(s)$ by iteration method?
4
votes
1answer
165 views

How to input and output partitioned matrices that show partitions and compute as normal?

I want to demonstrate multiplication of partitioned matrices as in the example here. Using the Insert Menu, you can build a matrix and draw lines between rows and columns. However, I want to be able ...
4
votes
1answer
108 views

Set number of columns in text-based interface

Is it possible to set the number of columns in Mathematica's text-based interface? Or disable word wrapping in the text-based interface ? Specifically, my concern is output from ...

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