# All Questions

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 ...
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 ...
130 views

### Strange behavior of DateList when converting string

DateList experiences some strange behavior which i cannot explain. This code works fine: ...
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 ...
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}, ...
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 ...
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 ...
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 ...
316 views

### Errors in Compile

I defined a function ...
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 ...
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 ...
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 ...
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 ...
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 (...
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 ...
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 ...
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 ...
335 views

### Typeset unbalanced brackets

In LaTeX, you can typeset expressions containing unbalanced brackets, by balancing them with an invisible delimiter \left. or ...
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: ...
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 ...
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? ...
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 ...
299 views

### Dependent Manipulate sliders

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

### Why can't Mathematica parallelize this?

The following code makes mathematica print "ParallelTable::nopar1: [...] cannot be parallelized; proceeding with sequential evaluation." ...
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 ...
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 ...
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?
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: ...
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 ...
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. ...
188 views

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 ...
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 ...
123 views

### Working of Date[]

Date[] returns the current date of local system, Date[1] returns {2012, 11, 15, 17, 41, 0.3161629}, ...
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: ...
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: ...
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 ...
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?
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 ...
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? ...
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 ...
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 ...
244 views

### How to Sort on row by row basis?

Say I have matrix how to sort on row by row basis to get:
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 ...