All Questions

3
votes
1answer
167 views

Manipulate Slider over discrete collection. Keyboard control.

I would like to create a Manipulate slider that iterates over a discrete set of items. Something like the following ...
4
votes
1answer
198 views

How to fix MIDI playback on OS X?

Sometimes sounds specified using SoundNote (i.e. things played using MIDI) don't play properly on OS X. Some notes are missing and some are stuck. At least this ...
4
votes
1answer
603 views

Solve inhomogeneous Poisson's equation, gives no result at all

I would like to solve the following two-dimensional inhomogeneous Poisson's equation in Mathematica including specific boundary conditions, and I know that an analytical solution exists, but ...
10
votes
3answers
317 views

Looking for an elegant way to construct this tensor-product-ish list

I would like to make the following matrix: ...
0
votes
1answer
79 views

Function or script which maxes out the CPUs?

I've been using Mathematica for awhile now and have never come even close to maxing out my CPU cycles. Are there any functions which consume lots of CPU cycles? Right now I am running a script which ...
1
vote
1answer
90 views

Performing operations on function lists

I am exploring the use of Dynamic variables for the ViewPoint and ViewVertical options in a ...
1
vote
1answer
87 views

How to pop out of a subsection in a notebook

Let's say I have a section in a notebook, which I begin with a cmd-4 keystroke. I type in some text and expressions, and now I want to introduce a subsection for ...
0
votes
0answers
60 views

how to generate repeatable Unique streams?

I need to label some data in arbitrarily nested ragged lists, with a stream of unique labels. It's very convenient if the labels are consecutive integers, starting at 0 or 1, and if I can produce the ...
3
votes
1answer
99 views

Export file with semicolon at the end of line

Is there a rule that tells Mathematica to set a semicolon at the end of each line (except of the last one)? My MWE is: ...
3
votes
2answers
670 views

Units, plotting and empty plots

maybe I'm completely newbie but I can't understand the behavior of units and the command plot. I'm doing some easy plotting of the state equation for gasses: ...
0
votes
2answers
131 views

Changing “Block[]” to a Manipulation

I have a graph here and I want to be able to manipulate the 4 parameters that are in the Block command. I want to watch the graph change as I change the parameters. I've done this before, but the ...
2
votes
0answers
282 views

Retrieving Data from Excel Using NETLink / Pulling data using RTD Link

Reference: I've looked at the posting Open excel file with Mathematica. My intention is to be able to use Excel's RTD capability in order to pull market data into Mathematica. To my knowledge, this ...
4
votes
1answer
623 views

What do the hashtags represent in the result of Solve, and how should I use them? [duplicate]

There is a function that I'm trying to get the inverse of. My function is a simple polynomial: Tn[T_] := 4/9 T^3/Tc^2 + 5/9 T Now I tried to find ...
1
vote
0answers
206 views

To what extent can NonlinearModelFit be sped up?

Can NonlinearModelFit be parallelized or compiled to allow one to achieve a scalable speedup for a fitting procedure? Attempting to use this function to fit a ...
5
votes
1answer
258 views

How to switch off messages on all kernels?

I am using ParallelMap for my code,however, it gives some messages that don't affect the evaluation process but fill up the memory and take some more time. So, I ...
0
votes
0answers
36 views

I'm definitely giving an integer, but I get Nest::intnm [duplicate]

I am attempting to make a small interactive plot that displays the plot of Cos iterated its times. Whenever I try to evaluate my ...
1
vote
1answer
95 views

sequence of matrix multiplications

My linear algebra book has questions that are are marked to use math software. There's probably some $50 guide on how to do everything but usually documentation has gotten me through. I've been kind ...
4
votes
2answers
267 views

Efficiently determining the largest minimum cost to travel from a fixed source to an arbitrary sink in a weighted graph

Let $v_i$ be a vertex in a graph $G$ with vertices $(v_1,...,v_N) \in V$ and edges $(e_1,...,e_M) \in E$ with associated weights $(w_1,...,w_M)$. Let $v_s \in V$ be specified vertex in the graph. In ...
0
votes
1answer
74 views

How does PolarPlot render a nested list of functions?

I am getting unexpected plots from PolarPlot when I provide a list of functions that I generate using Table. I suspect the ...
2
votes
1answer
326 views

How do you adjust tick direction on a 3d plot?

I have a 3d plot with oddly angled tick marks. Whether it's due to the viewing angle being unexpected or some other reason, the tick marks on the bottom axes are angled up along the sides rather than ...
5
votes
0answers
112 views

Are there any videos that show how different Mathematica expressions are evaluated?

Are there any videos that show how different Mathematica expressions are represented internally as object graphs and demonstrate how they are transformed during an evaluation? I am asking because I ...
4
votes
2answers
117 views

'kEINVALErr' error on startup

I have been using Mathematica 8 on an OS X system for quite a while now, but this morning it threw this error at me when I started the program up: Assertion 'kEINVALErr' failed at ...
1
vote
1answer
33 views

MatrixForm control inside Row[]

I would like to pretty print two column vectors of different lengths so that they are aligned at the top rather than centered, which seems to be the default. For example, ...
5
votes
1answer
858 views

Calculating volume between two surfaces of revolution

Once again, I'm very new to Mathematica and winging it as I go. I probably don't have the math education at this point to even justify buying it in the first place, but that's off topic. I wanted to ...
6
votes
4answers
4k views

Fitting a two-dimensional Gaussian to a set of 2D pixels

Imagine I have a set of data like the following: ...
6
votes
1answer
206 views

Specifying mesh in NDSolve

I am trying to solve a system of one-dimensional two-point boundary-value problems with NDSolve. I would like use a fixed mesh (specified by me) in the calculation. Is there a way to do this? The ...
0
votes
1answer
126 views

Returning a bounding disk or box centered on a coordinate in a 2D image

Provided a coordinate $c_k$ in a two-dimensional image, how can I return all of the pixels in a bounding disk or rectangle centered on $c_k$ of some specified dimension $d$? Update: Hat tip to Kuba ...
0
votes
0answers
230 views

DSolve expression doesn't evaluate

Can Mathematica solve $\; d^2/dx^2{}+ (1/x) d/dx\;$ form of equations? For example, I am trying to solve the system of equations given below: ...
4
votes
2answers
339 views

Removing not-a-number entries from an array of numbers

I have a list of {x, y, z} coordinates from a wavefront sensor I'm working with. However, not all of the imported points have actual values, but they still get ...
0
votes
0answers
25 views

Converting the output for variable assignments to a usable array form [duplicate]

Output from built-in Mathematica functions often has this form (e.g. from Solve): {1 -> {166., 254.214}, 2 -> {237.214, 254.}, 3 -> {121., 253.5}, 4 -> ...
6
votes
0answers
69 views

How can autocomplete entries be added for DownValues and Properties?

I'd like to assign DownValues to a symbol like this x["firstvalue"] = 1; x["secondvalue"] = 2; And then have the ...
2
votes
3answers
258 views

Isolating a prefactor in an analytical expression

I have a large mathematica expression that looks roughly like f = A1 Exp[a1 x] + A2 Exp[a2 x] + b1/x + b2/x^2 + c0 + c1 x + c2 x^2 where all the ...
3
votes
2answers
442 views

What is the default ColorFunction for 3D plots?

This should be a really simple question, but it isn't in the documentation for some perverse reason. I like the default ColorFunction that Mathematica uses for ...
1
vote
1answer
324 views

ParametricPlot with DSolve does not show anything

I manage to plot strn[t] and sig[t] where sig[t] is the solution from my DSolve. However, when I want to ParametricPlot sig[t] vs strn[t], I failed to do it as the parametric plot does not show ...
0
votes
0answers
94 views

Inconsistent results in fits from NArgMin

EDIT: Just realized I had misspelled "inconsistent." I'm using version 7.0. I'm trying to fit a (noisy) data set to a large-order polynomial. (Just for context: there isn't a model for the ...
-2
votes
1answer
205 views

Why doesn't Mathematica evaluate this limit?

I am trying to evaluate a few limits in Mathematica, and I can only get it to evaluate them in certain cases. I don't fully understand the evaluation order and when it substitutes numerical values in ...
1
vote
2answers
128 views

How can I make a plot of data saved in a .txt file? [duplicate]

My file. Txt has only two columns, where the 1st column is the time that the data was generated by the 2nd column has decimal values ​​1-100. Example: ...
3
votes
1answer
286 views

How to debug Mathematica crash?

If i have some program which crash Mathematica every time it's run. What are the steps to make a more informative report and/or how do i go about debugging it? EDIT: I guess essentially my question ...
1
vote
1answer
340 views

BVP - shooting method

I really don't know how to realize this method. The examples in internet and the reference aren't helpful for me. 1) I have the values for today: ...
1
vote
1answer
178 views

Plot image function together maintaining compatibility between their coordinate systems?

Is it possible to plot an image, i.e., draw it's pixels against usual coordinates? My goal is to plot my image and my function in the same coordinates. Update I drew an image of size ...
0
votes
1answer
121 views

Sorting a list of triplets by first element of each triplet fails

In the last line of code, I´m trying to order the matrix by the first column. I want to store in the Array t2tlistsorted ( 100 x 3 ), but I can´t. ...
6
votes
2answers
274 views

Why are we so sure about Map results?

I do abuse it often but when I have faced this feature first time I was really suprised: i = 0; (i++; # - i) & /@ Range[5] {0, 0, 0, 0, 0} What am I ...
1
vote
2answers
401 views

Make a histogram by giving the range and height of each bin one by one

I got the data of each bin by measurements like {start, end, height} and I want something like this picture: http://tinypic.com/view.php?pic=2i208hs&s=5 I ...
1
vote
0answers
191 views

Get path to end nodes in directed (partially cyclic) graph

I have a large directed graph containing small loops. I would like to extract all paths to all end nodes (no VertexOutComponent) with a given path length $n$. I ...
17
votes
1answer
396 views

Color scheme used by Colorize?

The Colorize function is often used to display the results produced by MorphologicalComponents: ...
2
votes
1answer
130 views

list manipulation [duplicate]

I have a list like the following: {{1, 3}, {2, 5}, {3, 6}, {2, 4}} I want the final list to be like that : ...
3
votes
1answer
159 views

Implementing new algebra for list-like objects

I would like to implement an algebra (addition, multiplication, etc.) for what is called "truncated power series" (TPSA) (Differential Algebraic description of beam dynamics). . These 'objects' (sets ...
5
votes
2answers
112 views

DictionaryLookup very slow

I'm trying to plot, given a list of words, how many words belongs to each language. I'm using the following code: ...
3
votes
2answers
107 views

Non-canonical re-ordering of nested lists

I have some data in the form: ...
2
votes
2answers
126 views

Select rows of matrix that are higher than a given row

Imagine I have the following matrix: X={{0,0,0},{1,0,1},{1,1,1},{1,2,1},{3,3,3}}. I want to select the sublists that are greater or equal than this list ...

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