1
vote
1answer
71 views

Series and that old ivar error

I am trying to compare plots of the function (1+x)^{1/3} and its power series. The code for the power series generates an error message referring to an invalid variable: 'General::ivar: -1.09993 is ...
2
votes
1answer
97 views

Sharpening extrema using DensityPlot

I have a data set where I really care mainly about visualizing the highest and lowest areas. DensityPlot suits my needs well, but ideally the maxima and minima would pop more from the rest of the ...
1
vote
1answer
985 views

Runge-Kutta 2nd Order ODE Solver

Suppose I have a 2nd order ODE of the form y''(t) = 1/y with y(0) = 0 and y'(0) = 10, and ...
0
votes
0answers
169 views

How to minimize the sum of squares of deviations from the mean?

I am trying to minimize the sum of squares of a deviation from the mean applying the following: Minimize[Sum[(Subscript[x, i] - \[Mu])^2, {i, 0, n}], x] It ...
1
vote
1answer
111 views

Animating arrows

I have the following Code: ...
5
votes
1answer
215 views

Procedural to functional style

The following code generates an iterative mapping of some trigonometric functions. I have a couple questions about it. The first question is how to optimize this iterative process using mathematica's ...
2
votes
1answer
108 views

Documentation build failed with Workbench

I'm starting to use Wolfram Workbench 2 to develop a Mathematica package. For the first time I tried "Documentation - Build" under the "Application Tools" but got fatal errors: BUILD FAILED ...
0
votes
3answers
205 views

saving outputs of loop

I am stuck on a problem. I have outputs generated at every iteration of a do loop. However, I want to save the outputs in some other file format, like text file etc, in such a way that i must be able ...
0
votes
1answer
109 views

Audio sample data from a Sound object

When generating a Sound object by using Sound primitives, like: Needs["Audio`"] sound = Sound[ListWaveform[{{1, 1}, {1.496, .7}, {2.501, .3}}, 265, 1]]; how can ...
2
votes
2answers
86 views

Alternative to Except in StringExpression when using StringMatchQ

According to this answer and the documentation for StringExpression, Except can only be used in StringExpression for classes of ...
1
vote
1answer
119 views

Matrix/tensor addition behaving funny under replacement?

I have two matrices I want to add, and one of the matrices is a tensor product of two vectors. I've used a SetDelayed to define the summed matrix, because I want to evaluate it for different values of ...
0
votes
1answer
140 views

how to apply a function to a list of tables

I have several files, and I want to extract for each of them a table, and then select just numbers, and keep only rows with five elements. My code works fine during import ...
2
votes
2answers
103 views

select from a list based on digits

I wish to know how do I count the number of occurrences of numbers that end in digits d. e.g. Say I create a list of Divisors of 12! I now want to count those divisors that end in 12. Like 12 & ...
0
votes
2answers
147 views

Improving code for comparing and modifying nested matrices

I have a matrix such as: ...
1
vote
2answers
77 views

Pattern matching to head with HoldFirst

I want to define a function that only operates on expressions with a head from a given list, such as f[expr:(_And|_Or)] := Print["LHS is ", expr[[1]]]; This of ...
0
votes
2answers
124 views

How do I perform the riffle function backward? [duplicate]

I know riffle will combine the lists {1,2,3} and {a,b,c} to be {1,a,2,b,3,c}. Is there a way to work backward and split the list {a,b,c,d,e,f} to be {a,c,e} and {b,d,f}?
0
votes
2answers
128 views

Output for $\LaTeX$

I have a Mathematica command WriteString[str,TeXForm[ToString[a]^ToString[Divide[p, q]]]] where a=47, ...
0
votes
1answer
105 views

Is there a way to make the MemberQ function apply to a list?

Is there any way to ask a boolean question if the elements of the list {2,5} are in the list {1,2,3,4,5}?
2
votes
2answers
155 views

Why Doesn't Mathematica Simplify Combinations of Quotients? (Integer Division)

I stumbled across this as part of a more complicated formula but it can be shown very simply: ...
0
votes
1answer
140 views

How to define a new stochastic process which is function of another process?

I need to define a new process from for example Wiener process like $U(t)=f(W(t))$, (for example $f(x)=1+x^2$ ) and then calculate the average like $\langle U(t)U(s)\rangle$. Is it possible?
0
votes
1answer
51 views

Importing a Matrix whit different column numbers depending on the row

I have a bunch of coordinates given in a file. The file contains Startpoints and Endpoints of arrows in columns(Example): ...
5
votes
3answers
3k views

How to force 2+2=5

I was looking at this question (writing a program such that 2 + 2 = 5) and tried to write something in Mathematica, but I couldn't get something to work without completely replacing ...
3
votes
1answer
130 views

Reverse-order Negative BarSpacing

Suppose I have some data for a bar chart: ...
1
vote
1answer
298 views

Find polynomial equation for set of 3D data

data was given in columns in the order {y, x, z}, with y dependent on x, z ...
0
votes
1answer
110 views

why I can not find the correct derivative with D

the coupled ODE is ...
8
votes
2answers
379 views

Aligning two lists

I have two lists, L1 and L2, each with a key and some data. Let us say the key is a person's name, a string, and the data follows. (To respond to rasher's query:) Let us also assume the lists are ...
1
vote
0answers
83 views

Help function ? sometimes doesn't show help

I was just wondering if this is a known bug. When I want to get basic help using the ? command before some function name, it typically works for a while, but I've ...
1
vote
1answer
67 views

Graph label smushed in when printing

I was playing around with the printing options because at first my notebook's printout was strangely way too large. However, after apparently solving the problem, now I noticed that when I print out ...
1
vote
0answers
45 views

Placement of pattern matching rules in functions [duplicate]

Is there any difference at all between f[x_Integer /; x >= 0] := x + 1; f[x_Integer] := x - 1; f[x_] := Null; and ...
3
votes
1answer
71 views

How to draw guide lines spanning between two panels or graphs?

I would like to draw the blue guide lines as shown spanning between the top and bottom graphs. Any help is appreciated. Thanks!
4
votes
1answer
245 views

find cycle in directed graph

Given a digraph G in the form of a list of edges, is there implemented some command that returns a directed cycle in G of ...
1
vote
2answers
304 views

position of element in a list using a function

How can I find in a list l the positions of all elements satisfying a boolean function f. For example, how can I pick in ...
3
votes
1answer
167 views

Partial zeta curlicues

I asked a question at MSE and Raymond Manzoni provided an excellent answer that included these visuals: I made a very basic attempt at recreation with ...
1
vote
2answers
112 views

How to remove a gap between the chart labels and the frame in a BoxWhiskersPlot

When making a nested BoxWhiskersPlot with chart labels, the labels are nicely spaced below the bottom frame when using labels for all nested data ...
0
votes
1answer
227 views

Plot slope field in Mathematica for a difficult differential equation

I am trying to plot slope field for $\ddot{a}(t)$ for this differential equation but I don't know how to $\frac{d}{dt}\ddot{a}(t)=2\frac{\dot{a}(t)}{a(t)}\ddot{a}(t)$ I want to show that already ...
2
votes
1answer
176 views

Finding the roots of a function with a parameter

I am using a differential equation method for finding the roots of a function. My function is much more complicated but I can illustrate my problem with a trivial example. The problem occurs when ...
1
vote
1answer
216 views

Placing many arrowheads on curves

I can't find anything anywhere on the web to help me with this. My plot: ...
2
votes
0answers
51 views

Will custom fonts in my notebook be carried over?

In my notebook, I have Open Sans (a free font) as a text font and Consolas (a paid font) as a code font. Those fonts are coded into the stylesheet of my notebook. My question is: if I send someone a ...
4
votes
3answers
2k views

Creating a 3D List Line Plot From Discrete Points

Given the following Runge-Kutta ODE solver and the graphical output below, how do I get a 3D line plot instead of a 3D point plot? I see that there is no ListLinePlot3D function, so I thought it might ...
2
votes
2answers
143 views

Use only exponents (no radicals) in output expressions

Radical symbols ($\sqrt{\,\,\,\,}$) are the devil. Is there any way to get mathematica to never use them, and instead express everything as an exponential? i.e. I want ...
3
votes
0answers
66 views

How to include automatic references to cells styled with DisplayFormulaNumbered

Under the Style menu, there is an entry called DisplayFormulaNumbered. It does exactly what it seems to suggest: it indexes the ...
5
votes
2answers
187 views

Syntax highlighting conflict

I'm trying to syntax highlight this expression: x=$\sqrt{\pi }$//N and from various sources I've learned that x (the assigned symbol) belongs to context Global while the Pi and N belongs to System. So ...
2
votes
1answer
112 views

Remove singularity at zero from $-((i^{-n} (-1 + i^n)^2)/(n^2 π^2))$

The expression h[n_] = -((I^-n (-1 + I^n)^2)/(n^2 π^2)) is real for all integers n. Although indeterminate at ...
6
votes
2answers
365 views

Why does Equal[“string”, False] not evaluate to False?

Why does Equal["string", False] not evaluate to False? I would have thought Mathematica could prove that these two things are ...
3
votes
6answers
340 views

How can I construct a distance table?

I have a list of city names (of arbitrary length), f.e. c = {"BAL", "NYC", "LAS", "AUS"}; and the distances between them : ...
0
votes
0answers
98 views

Invisible characters being inserted into the output from FindMaximum

I have been using Mathematica for quite some time but I have never seen anything like this. It started without warning and I am not sure how to fix this. Please have a look at the following example ...
3
votes
1answer
98 views
6
votes
1answer
198 views

How to modify font for all text fields?

I know that one can modify the StandardForm style so that all input and output codes (and maybe other things too) follow that style. This makes it tricky to make input code different from output code ...
2
votes
1answer
154 views

How can I make my plot continuous?

Looks like plots became of low quality in Mathematica 9? How to make Mathematica to plot continuously? Logically current plot style is solid.
8
votes
2answers
361 views

Finding all sets of elements with two common elements in a large dataset

I have a very large network of atoms ($\approx 10^6$ atoms) with fixed positions that resemble a cellular structure: I have two files including: fixed locations of each atom set of points which ...

15 30 50 per page