10
votes
7answers
823 views

How do I get rid of a “jump” in my plot?

How can I prevent plotting functions from "connecting" inside a plot points that should "wrap around" outside the plot? For example, how do I eliminate the horizontal lines running across the ...
7
votes
2answers
299 views

Compiling a spatial predator-prey model and optimising it for speed

I just made a spatial predator-prey model but it runs a little slow and I am seeking some advice on how to compile it to optimise it for speed. I first define matrix with 0 for an empty site, 1 for a ...
4
votes
1answer
130 views

Strange behavior of DateList when converting string

DateList experiences some strange behavior which i cannot explain. This code works fine: ...
2
votes
1answer
409 views

How to modify a matrix to satisfy a special condition?

I have matrix like this: How do I modify this matrix to make it satisfy the following condition: For each element {i, j} in the matrix the sum of the elements of row i must be equal to the sum ...
0
votes
1answer
200 views

Assign the result of Solve in a list [duplicate]

Possible Duplicate: Assign the results from a Solve to variable(s) I want to assign the results of a Solve command in a list. For example Solve[-((287 s^3)/50) == 0, s] returns {{s -> 0}, ...
7
votes
1answer
238 views

How do you use SystemsModelFeedbackConnect?

I'm trying to grasp the new control system functions in Mathematica 8. I'd like to connect a controller model to a model of a plant to simulate the behavior of the system. I define a simple servo ...
20
votes
2answers
3k views

How to import all files of a folder at once?

I know how to import one textfile by calling its name filestring = Import["myfile.tex", "Text"]; Then "filestring" is a string with the myfile content. How do ...
13
votes
1answer
423 views

Easy way to export Graphics3D as triangles with VertexNormals?

I would like to export an arbitrary Graphics3D object as a text file containing: list of vertices vertex normals triangle faces ...
3
votes
1answer
316 views
3
votes
4answers
1k views

how to draw a moving point on a curve?

I almost remember an example that has a moving red point on a given curve, which will moving time and time again, with no controls... now, here is my question: given a curve by ...
6
votes
1answer
523 views

Placing Manipulate controls in multiple columns

I have a Manipulate construct with a square Graphic on the left side and all the controls placed on the right side. There are so ...
4
votes
1answer
154 views

Issue with setting up docked cells

Normally I try to stay away from asking RTFM- questions but concerning docked cells I am currently groping in the dark. The documentation examples tell me how to create a new window containing a ...
5
votes
1answer
426 views

Enabled option for slider in Manipulate not updating dynamically

In a Manipulate expression I have a slider control which has the Enabled option ...
1
vote
1answer
692 views

Use selfdefined ColorFunction to encode z dimension with predefined limits

In my last question we defined a colorfunction cf. Now I want to use this ColorFunction for a number of different plots (...
2
votes
1answer
399 views

Use output from Plot3D as an object in Graphics3D that I can transform

I'm trying to draw up an optical system where I can show an example of wavefront error on an exit pupil. It would be great if I could take the results of a 3D function from Plot3D and use it as a ...
2
votes
3answers
348 views

Notification sound when simulation done? [duplicate]

Possible Duplicate: Customize front end to add notifications when evaluation finishes? How to setup sound alert notification when simulation is complete? I need to do something else while ...
6
votes
1answer
386 views

Find the list of weather stations for specified cities

I wrote some code which retrieves temperature data from three cities every hour for five days. My problem is that the default station from which WeatherData[] gets ...
10
votes
3answers
335 views

Typeset unbalanced brackets

In LaTeX, you can typeset expressions containing unbalanced brackets, by balancing them with an invisible delimiter \left. or ...
0
votes
1answer
372 views

How to create function that classifies sample data

I want to create expression, that classifies samples ( 4 weather features -> decision). Example training data: For the values that i have data for, I can use rules: ...
4
votes
2answers
728 views

Define a color function based on color samples obtained from ColorBrewer

I am quite new to mathematica and I am searching for a way to create a smooth colormap based on the samples given by http://colorbrewer2.org/ . Is it possible to create a interpolated function from ...
4
votes
6answers
255 views

Sorting Matrix elements

I have matrix in as shown, consisting of real numbers and 0. How can I sort it to become out as shown? ...
7
votes
1answer
482 views

Log-scale histogram bug

Not really a question, more a solution to what I call a bug in mathematica v8(.0.0.4). I already sent a bug report to Wolfram. Problem The documentation for the Histogram-function explains the ...
10
votes
2answers
299 views

Dependent Manipulate sliders

I would like to use dependent sliders in Manipulate. First slider K0 should be independent and varied from ...
3
votes
1answer
283 views

Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
1
vote
0answers
244 views

Return Functions from parallel execution of module

I wrote a module which numerically solves an ODE using NDSolve. The result from this is e.g. either ...
7
votes
1answer
324 views

Anyone recognize this heatmap? [closed]

Anyone know the origins of the attached heatmap/daylight overlay? I see it on the Mathematica homepage all the time and I even saw it once on Wolfram|Alpha launch video. I know there are ways to ...
4
votes
1answer
318 views

Can Mathematica check spelling during typing?

I can't see a way to get Mathematica to check my spelling as I type. Is this feature not supported? I've done everything I can think of with my options: Is there a setting I'm missing?
1
vote
1answer
831 views

How to scale vectors in VectorPlot?

I generated some pics from 2 datum,one in $x$ direction and the other in $y$,so I used the commands: ...
1
vote
1answer
128 views

How do I find the value of specific printing options?

I'd like to programmatically save (and then temporarily change and restore) specific printing options. I get as far as Options[Notebook, PrintingOptions] but ...
5
votes
3answers
482 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. ...
7
votes
2answers
188 views

Why isn't Simplify doing more simplification of this expression?

When I try this Simplify[(1-a)*(1/(1+x*m))^(1-a)(1+m)^(1-a) + (1-a)*(x*m)^a*((x*m)/(1+x*m))^(1-a)*(1+m)^(1-a)] the output is $$\frac{(1-a) (1+m)^{1-a} ...
10
votes
2answers
366 views

Determining the default Method used in optimization and root-finding algorithms

Is it possible to extract the Method which is used in functions like NMinimize, FindRoot, ...
7
votes
3answers
342 views

Operations on elements of ragged lists

Suppose I have a list of lists with different lengths, sorted from longest to shortest ...
5
votes
2answers
206 views

Is it possible to define more than 9 shortcuts for notebook cell styles?

You can define shortcuts for notebook cell styles in the stylesheet editor, by adding MenuCommandKey->"7", etc. to the style definition. That is, you can define ...
5
votes
3answers
773 views

Is it possible to typeset left and right angle brackets?

I would like to typeset the following in a Mathematica notebook: $$\langle P \rangle$$ Is it possible to typeset left and right angle brackets? In $\LaTeX$, they are given by ...
10
votes
2answers
1k views

How to improve the typesetting of mathematical contents

Until I started diving into Mathematica, I was not using much computer software for symbolic computation. I did my analysis by hand on blank sheets, the calculations using Python or MATLAB, and the ...
0
votes
1answer
105 views

Defining functions from expressions of variable lengths

I have a list of symbols that I have defined using d = Table[Symbol["d" <> ToString[i]], {i, 1, n}] giving ...
1
vote
1answer
123 views

Working of Date[]

Date[] returns the current date of local system, Date[1] returns {2012, 11, 15, 17, 41, 0.3161629}, ...
1
vote
1answer
323 views

How to do conditional matrix division when elements are a combination of zero and real numbers?

I tried to divide two large matrices DLand PL of size 100,000 x 5 each and they look like this, DL= and PL= By using conditional function: ...
1
vote
3answers
108 views

Timing display of Graphics (Front End timing)

I want to know how much wall-time it takes to display a Graphics For example this one: ...
6
votes
3answers
172 views

Is there any way to collect only variables with a specific power?

Suppose I've got this: In[13]:= Expand[(a + b) (b + c) (c + a)] Out[13]= a^2 b + a b^2 + a^2 c + 2 a b c + b^2 c + a c^2 + b c^2 And I want to collect only ...
0
votes
0answers
35 views

Why isn't the matrix product computed? [duplicate]

Possible Duplicate: Why does MatrixForm affect calculations? I have the following input: Why is the matrix not computed, giving me a $2 \times 2$ matrix?
3
votes
1answer
315 views

Plot maximum and minimum temperature of a day for range of time interval

How to display (in any graphic representation) the maximum and minimum temperatures for one city in one of these selected time periods over the 5-day period? The time periods are: Morning (06:00 to ...
2
votes
1answer
195 views

Difference between Map[f[#] + g[#] &, {a, b, c}] and Map[f[x]+g[x]&, {a, b, c}]

Map[f[#] + g[#] &, {a, b, c}] vs Map[f[x]+g[x]&, {a, b, c}] My question is: why is the output different? ...
1
vote
1answer
124 views

How can I use several data fields drawn from curated data at once?

How can I use "MinTemperature", "MaxTemperature", and "Temperature" properties of ...
2
votes
1answer
923 views

How to define the Einstein summation convention in Mathematica?

How to define a Einstein summation convention in Mathematica? Say, how to let Mathematica know T[i,i] equals ...
1
vote
1answer
244 views

How to Sort on row by row basis?

Say I have matrix how to sort on row by row basis to get:
4
votes
2answers
157 views

Function behaves differently inside a package than outside

I defined a function TestHead in a notebook as follows: TestHead[z___] := TrueQ[{z} == Cases[{z}, x_ /; Head[x] === avar]] to ...
4
votes
1answer
855 views

How to print coordinates above certain points

How do I place the x and y values of the points I have found (maxandmindistance) above the point in a plot? Here is my code so far: ...
6
votes
1answer
319 views

Why is MapIndexed better than mapping over a range?

Background I'm working on an application in which I need to create and control two sets of locators. I know from reading the Mathematica documentation and certain posts on Mathematica.SE that this ...

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