16
votes
2answers
1k views

Difference between AbsoluteTiming and Timing

I need to evaluate the efficiency of my code. Therefore I would like to evaluate the time the code need for some calculations. Mathematica gives me two possibilities for this kind of evaluation: ...
16
votes
1answer
362 views

What does “suitable for symbolic manipulation” in the documentation mean?

This question is related to this other one I posted on Stack Overflow some time ago. There, in a beautiful answer, acl (with some unhumble editing done by me) showed that the derivative of ...
16
votes
1answer
330 views

Estimating progress on plots

When plotting a slow function, it would be nice to know how much of the work has already be done. However due to the refinement algorithm, simply monitoring the integration variable doesn't give an ...
16
votes
1answer
497 views

When importing GIF animation, how to find the correct list of “DisplayDurations”?

When importing GIF animations with variable frame durations, the settings for "DisplayDurations" are not recovered correctly. As an example, I'm using the movie from this earlier question: Here I'm ...
16
votes
2answers
457 views

Ad hoc graphics primitives-like objects

Sphere is one of the three-dimensional graphics primitives available in Mathematica and can be easily used to created very useful images. For instance, in the ...
15
votes
2answers
725 views

Why do certain values in ArcSin not fully evaluate?

This is a continuation of: Why do certain fractional values in TriangleWave not evaluate? The analysis by R.M and rasher revealed that problem to reduce to the behavior of: ...
15
votes
2answers
1k views

How to get StreamPlot to draw many hundreds of streamlines?

For artistic reasons, I want to draw an extremely dense StreamPlot with something like a thousand streamlines. I tried setting ...
15
votes
6answers
683 views

On generalizing Partition[] (with offsets) to sublists of unequal length

The usual Partition[] function is a very handy little thing: ...
14
votes
7answers
600 views

A function that accepts a pair or a list of pairs

Probably a duplicate, but it's not easy to search on "lists". I have a function that accepts a list of lists, say {{a1, b1}, {a2, b2}, {a3, b3}} and performs some ...
14
votes
1answer
269 views

Is the sharing of variables in Module/Block within Compile documented behavior?

Today I noticed something, I think for the first time. When used inside Compile variable values within Module (and ...
14
votes
4answers
2k views

Creating overlapping histogram plots

I am plotting two histograms on the same graph: g1 = Histogram[bc, ChartStyle -> {Red}] g2 = Histogram[bcx] Show[g1, g2, PlotRange -> {{0.1, 0.6}, All}] ...
13
votes
2answers
1k views

How do I add arrowheads to circular arcs?

I have figures containing several arcs showing the extend of angular measures, and would like to indicate the directions in which angles are measured with arrowheads. How do I add an arrowhead at the ...
13
votes
4answers
663 views

Constructing a list that includes a leading zero (01,02,03 … 55, 56, etc.)

I am constructing a list for use in file operations. Say I want to create list which contains values from 01 to 87. The kicker is that the first nine integers need ...
13
votes
1answer
442 views

Which Distributions can be Compiled using RandomVariate

Recently, Oleksandr kindly showed a list of Mathematica commands that can be compiled. RandomVariate was part of that list. However, whether this can be compiled depends upon the distribution that is ...
12
votes
1answer
297 views

What is the real default CellEvaluationFunction?

The default CellEvaluationFunction is Identity but one can quickly see that this is handled specially as an equivalent function, ...
12
votes
1answer
233 views

using MathLink for communication with external program from my C program without Mathematica

I have a compiled program with MathLink. I want to use it from other C program, without Mathematica being involved at all. If i create my program with MathLink and connect to this external program, ...
12
votes
4answers
2k views

Graphics plot of point using unfilled circle

I'd like to be able to place points on a plot using Graphics[{Point[{a,b}],....}] but have the plot symbol be an unfilled circle. I've looked around but can't find ...
12
votes
2answers
425 views

Are there advantages to using generalized Part extraction instead of specialized functions like First, Last?

There are many ways to extract different parts of lists in Mathematica. For example, the first part of a list v can be accessed either as ...
12
votes
2answers
321 views

Split a Unicode string maintaining uppercase characters

I want to split a string according to a predefined set of substrings (lowercase), though the actual text can contain uppercase characters anyplace. The task is to find the matches, longer preferred ...
12
votes
3answers
949 views

Number format of axes in a plot

How can I have a conditional format of the values appearing in the axis of a plot ? I have in mind the number format options available in Excel for plots as described here ...
12
votes
7answers
641 views

Equating matrices (or higher order tensors) element-wise

Say I have two matrices (or, as in my case, higher order tensors) $A,B$, and I want to solve the equation $A=B$. To do so , I need a list of equations that equate entry-wise the elements of $A$ and ...
11
votes
3answers
493 views

Rotate a grid, made up of lines, so that it aligns with the xy axes

While working on an answer for another problem I hit upon one of my own. I took the image given in that question and cleaned it up so that I could detect the grid lines: ...
11
votes
4answers
379 views

What's fastest way of defining 10^5 down values?

I want to define isGood[___] = False; isGood[#] = True & /@ list where list is a list of several million integers. ...
10
votes
1answer
445 views

Automating FTP upload within Mathematica?

I have MMA-generated html and would like to automate uploading to a named directory to a web host via SFTP or HTTP POST, ideally without creating local temp files. The closest question I could find on ...
10
votes
2answers
173 views

Globally loading packages while using a CellGroup as the default context

I have a notebook I wish to set up where the sections are conceptually related to each other. But, I wish to isolate them from each other programmatically, so that they do not interfere with one ...
10
votes
1answer
508 views

Finding a Specific Line in a Package

In a package I am developing, I accidentally left this line Protect[ uncompleted prior to running the package. Mathematica produced this error message ...
10
votes
1answer
166 views

Inspecting non-variable state from a breakpoint in Workbench

Suppose I'm stopped at a breakpoint in Workbench, say at one of the y = ... lines in: ...
9
votes
2answers
294 views

How to see which arguments are passed into a function

It is often that one wonders which arguments are evaluated before being passed into a function. I would like to know if it is possible to see which argumets are being passed into a function without ...
9
votes
2answers
269 views

Problem with PlayerPro recognizing a proprietary package

This question follows on from my earlier question Can Wolfram's Player Pro Use Proprietary Packages. That question appeared to have established that, yes, PlayerPro can use proprietary packages. ...
9
votes
3answers
657 views

Dashed mesh behind 3D object

I am trying to create a simple, almost transparent 3D sphere with a mesh that is made of solid lines if they are on the front surface (i.e. if they are directly visible) and of dashed lines if those ...
9
votes
1answer
326 views

LogPlot axes labels destroyed when working in high precision

(I'm using Mathematica 8.) I have a Taylor series: poly = Normal[Series[E^x, {x, 0, 10}]] I want to produce a log-linear plot of the error. This is easy enough ...
9
votes
2answers
255 views

How to find a specific error message?

Is there a way to find an existing error message in the System` context, that is used for a certain case? I want to include a message in a custom function that ...
9
votes
1answer
592 views

Compiling a recursive formula

My question is related to computing what is called "invariant measure" for a particular well known fractal - the Sierpinski triangle. We have an array m of four two by two matrices, say ...
9
votes
2answers
2k views

How to get Matlab data imported with the same dimensions?

I have some Matlab image data with the following dimensions (output is from Matlab): >> size(im) ans = 86 86 3 45 The data imports just fine ...
9
votes
1answer
1k views

Construct 3D image from multiple 2D images

My goal: How to (1) construct 3D image for visualization. (2) how to write 3D array or image into binary raw file. Is there a way to accomplish this in Mathematica? Alternative_Answer for: ...
9
votes
2answers
7k views

Figuring when the minute and hour hand coincide on a clock

I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
8
votes
2answers
149 views

How to correct this, `f[a_] := FindRoot[eq == 0, {x, 0.5}]`, where `eq` contains a parameter $a$, without using `eq[a]`?

I want to solve an equation with a parameter $a$, and define the result as a function of $a$. It is something like this: ...
8
votes
3answers
181 views
8
votes
2answers
254 views

How to draw the image of a circle under the action of a transformation of the phase flow?

How to draw the image of a circle $x^2+(y-1)^2<1/4$ under the action of a transformation of the phase flow for the equation $\dot{x}=y,\ \dot{y}=-\sin x$? Here $\dot{x}$ means $dx/dt$. Any help or ...
8
votes
1answer
485 views

FourierTransform and Partial Derivatives?

I have a function of three variables $f(x,y,z)$, and it obeys a linear partial differential equation. I'm checking my by-hand calculations with Mathematica. I want to convert the PDE into the ...
8
votes
3answers
422 views

Image Processing: Concrete test blocks

Background Concrete is mixture of aggregates and cement. Aggregates are composed of different sizes and colors. Core samples are taken by drilling in order to test the strength of concrete . They are ...
8
votes
2answers
1k views

How to approximate a given WAV file with trigonometric series?

I'd like (together with a few people) to prepare a presentation about Fourier series for middle/high school students. I thought it might be quite cool to play a violin sound from, say, a WAV file, ...
8
votes
3answers
2k views

Derivative of real functions including Re and Im

When deriving functions using Re, Im or Arg (and probably some other functions as well), ...
8
votes
1answer
171 views

How can I make CurrentValue for font characteristics pick up the font of the output not the input cell?

The command CurrentValue (documentation) allows you to access various properties of fonts, such as x-height, line height, and various measures of width such as ...
7
votes
2answers
476 views

How to draw line connecting points on circle

Consider the list {1,2,3,4,3,4,2,1}. I want to label these points on circle the way they appear on list(clockwise, counter clock wise doesn't matter). After that I want to connect same points by ...
7
votes
1answer
268 views

Counting elements which are inside another element on a different colour channel

I have a 3-channel image which shows red and green points (certain labelled proteins) inside blue regions (cell nuclei). After applying some segmentation filters, the resulting image is as follows: ...
7
votes
1answer
727 views

Drawing a graph with specified edge lengths

I was wondering if it was possible to ask Mathematica to draw a graph provided some set of vertices: $(v_1, ..., v_N) \in V$ connected by $M$ edges $(e_1, ..., e_M) \in E$, where the length of each ...
7
votes
3answers
240 views

How to set a TraditionalForm output for a symbol

How do I set a TraditionalForm output for a particular symbol/function? In particular I would like my user-defined symbol ...
7
votes
1answer
280 views

How can I extend BinCounts to work on Times and Dates?

I want to extend BinCounts to work on a list of times or dates, binning them by Day, Week, Hour of the Month, Day of the Year, etc... So given a list of times and a time bin spec, I need to calculate ...
7
votes
3answers
217 views

Pattern matching Q for rectangular data matrices

Given a List of rectangular nx3 arrays of data, each of the form {...,{x,y,z},...}, (the ellipses are not Mathematica pattern syntax, just for illustration). Some members of this list may be - by ...

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