4
votes
1answer
432 views

Catching and debugging numerical errors in compiled functions

I have a compiled function (that was created using the second method of this question). Basically it's using a compiled closure. The problem is that for some parameter values it does not evaluate. ...
3
votes
2answers
164 views

Import[] exception possibly caused by ToString[] behaviour which I cannot explain

Let me just start by pointing out I'm a new StackExchange user as well as a new Mathematica user (started today!) I mention this as a context to my ineptitude :) I am attempting to read through a ...
2
votes
1answer
182 views

Defining a function that handles Dynamic arguments similar to Built-ins

Firstly please note that I'm using simply Dynamic behavior to illustrate my question, I'm not asking how to move a Disk or make ...
2
votes
1answer
408 views

How do I plot a system with gain, first-order lag and time delay?

I want to plot the output response of a system with gain, first-order lag and time delay, where the transfer function is tf = 2 Exp[-0.1 s]/(.1 + s) To plot a ...
2
votes
1answer
213 views

ParallelTable and Precision

I'm using ParallelTable[] to calculate a function over a range of my parameters , ($\omega,\ell$). This seems to be working well (in terms of speed increase) except ...
1
vote
0answers
89 views

Symbolic FindInstance

I'm wondering if there is any way of doing something like the following: FindInstance[x < y, {x}, Reals] and getting, as a possible return value, ...
4
votes
1answer
214 views

command to expand quaternion multiplication

Is there are any command to expand quaternion multiplication as below STEP by STEP. Below is equation from my text. I'm self learner and for some reason I can't wrap my head around quaternion ...
8
votes
3answers
494 views

How can I convert x^2 to x*x?

When I try the following code: a b^2 c /. b c -> e Mathematica gives me: a b^2 c but what I want is: ...
2
votes
2answers
94 views
12
votes
2answers
867 views

Using a ListDensityPlot to map color onto a ListPlot3D graph

I have a 3 column list of data points. The first two columns correspond to x and y coordinates, with data points creating a surface in the z direction from column 3. This gives me a nice wavy ...
5
votes
1answer
316 views

Enabled option for slider in Manipulate not updating dynamically

In a Manipulate expression I have a slider control which has the Enabled option ...
11
votes
1answer
641 views

Plot showing discontinuity where it shouldn't

I was trying to integrate a continuous function with a kink and I did it two ways and both ways the plot of the result shows a discontinuity. I also later want to differentiate the Integrated ...
6
votes
0answers
225 views

Realtime audio processing using Dynamic

Can I make real time audio processing with Mathematica in the same way I can do with images using Dynamic[CurrentImage[]]. I know that is possible to use ...
0
votes
1answer
340 views

Can an Interpolation function be 'saved'? [duplicate]

Possible Duplicate: Save interpolated function I am importing tables with sizes of 100k - 500k rows and 4 columns. The larger the table, the slower my Mathematica runs for all computations ...
2
votes
1answer
897 views

How to export data from excel specific cells into mathematica?

How to export data from excel specific cells into Mathematica? Given that the spreadsheet tab is named XYZ and that I have several cells at various locations in the same column in Excel that I want to ...
1
vote
3answers
152 views

Logical operations on a list [duplicate]

Possible Duplicate: Applying And to lists of Booleans I have two lists filled with logicals: ...
3
votes
1answer
273 views

Small Issue with Chebyshev Derivative Appoximation

I am trying to get approximate the derivative of a function from its Chebyshev expansion. I start out with the following random function ...
6
votes
1answer
224 views

Return a Part by Reference? (For accessing hierarchical / structured data)

Is there a way to return a part of a list by reference, for reading and writing? I want to do this so I can easily manipulate "rule-styled structured", i.e., hierarchical data that is loaded from a ...
7
votes
1answer
713 views

How does one draw a parallelepiped in Mathematica?

I'm a bit new to the application, and I'm not sure how to draw a parallelepiped in Mathematica.
11
votes
4answers
374 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. ...
2
votes
1answer
243 views

About high dimensional integrals

I want to be able to do high dimensional integrals like, (..naively I wrote it as this..) ...
5
votes
3answers
157 views

Comparing Unequal Lists of Surnames to Establish Over or Under-Representation

I've been using Mathematica to explore historical records. I have two long lists (one is 69k, the second 17k) of unequal length. They are like so (FWIW, the first list is the first 40 entries from the ...
4
votes
3answers
336 views

Generate a Combination of letters by a number

I'm trying to write a function f. example: ...
1
vote
0answers
221 views

Can mathematica simplify an expression setting simplified answer equal to zero?

Basically I want to reduce something like: Subscript[P, 4] - Subscript[P, 5] == Subscript[R, 4, 5]* Subscript[i, 4, 5] when only one of them is known (...
2
votes
1answer
223 views

Creating a matrix from the output of a variable inside a for loop

I would like to enter the results of the following loop inside a matrix as its elements: ...
7
votes
1answer
664 views

Is Abs[z]^2 a bad way to calculate the square modulus of z?

For a numerical quantity z, Abs[z] returns the square root of the sum of the squares of the real and imaginary parts of ...
3
votes
1answer
211 views

Debugging graphics

All the examples I am seeing on internet are related to normal functions that carry out loops and assignments but I have not seen one example where I can see a graphics based program being debugged. ...
0
votes
2answers
569 views

How to calculate FDCT

I'm new to Mathemtica and I'm trying to calculate Discrete Cosine Transformation FDCT. I found the FourierDCT built-in function, but not DCT, so I need to implement it. I have tried couple of ideas ...
4
votes
2answers
394 views

How to create a simple interface to get file path and execute some code on it?

I need to create a simple user interface to choose one file in the notebook directory, import it and execute some functions on the imported data. For the first version I created this code: ...
3
votes
1answer
267 views

Opening a notebook from command line in an existing front end instance

I am using Linux, and I would like to be able to programmatically open notebooks in a running Mathematica instance from the command line. Currently, doing something like ...
6
votes
1answer
117 views

LinearSolveFunction unusable if stored to disk?

I encounter a problem when saving a LinearSolveFunction to disk, where the LinearSolveFunction is obtained with LinearSolve for ...
11
votes
1answer
605 views

How can I make hatching filling of plot

How can I make hatching filling of plot Like this: I use another one plot with shifting to make filled area above: ...
13
votes
6answers
604 views

How can I fill-in this Pentagram?

This is my code: Graphics[{EdgeForm[Yellow], Yellow, Polygon[Table[{Cos[t], Sin[t]}, {t, 0, 4 π, (4 π)/5}]]}] which gives this: but I want to get: How?
11
votes
1answer
393 views

Export data to Excel with adjusted column size

I'm trying to export some data with formats into Excel. It works ok, but the columns size get not properly adjusted. I don't want to use some complicated solution based on this example. In my tests, ...
7
votes
1answer
303 views

Guides for programming CDFs

Are there any tutorials for programming high-quality CDFs, like the interactive calculus textbook presented at wolfram.com? Mathematica's Help is extremely impressive but it really does not help much ...
3
votes
3answers
265 views

Proving a recurrence in Mathematica

I have $$j_n=\int_0^1 x^{2n} \sin(\pi x)dx.$$ How do I show that $$j_{n+1}= \frac{1}{\pi^2}(\pi- (2n+1)(2n+2)j_n)\, ?$$ I keep getting a recurring integration by parts and I can't simplify it. ...
1
vote
2answers
130 views

How to mix Unevaluated property of function arguments with expression assignments?

This is a follow-up to my (solved) question How to distribute a generic function of two arguments (without evaluating the arguments) Say, I have a binary function ...
3
votes
0answers
143 views

Why doesn't Log[Gamma[]] simplify to LogGamma[] where it could?

I have been playing with various equations involving amount of permutations in relatively large sets. Easiest way to look at these is something like Log[10, bignumber!] . Often expressions, even ...
1
vote
2answers
236 views

Inputting two arrays for a module in Mathematica

I am relatively new to the Mathematica enviroment and not sure where I am going wrong. I have evaluated the question and understand it, but dont know how to exactly create a module for it. The ...
23
votes
1answer
419 views

Creating a package of special plots

In my work as a math teacher, I create lots of graphs to illustrate ideas. I have lots of math books and will often try to duplicate a particular style of graph. Below, one very simple example, ...
1
vote
1answer
395 views

Equivalent of Python's “all” function in Mathematica

The Python function def isPrime(n): return all(n % i for i in xrange(2, n)) checks if a number is a prime number by using ...
4
votes
2answers
252 views

How to save a web page in mathematica?

For a given web page http://www.nytimes.com/, is it possible to save it as : first: only HTML(within css) second: more elements(include pictures and so on) just like what a browser can do. ...
11
votes
1answer
287 views

Better Autocompelete for the Front-End

I wonder if it is possible to improve the front-end's autocomplete capability. Compared with some other more sophisticated editors/IDEs, such as eclipse, Mathematica's front-end does not provide a ...
1
vote
1answer
492 views

Calculating an exact orthogonal modal matrix in Mathematica

I can calculate the modal matrix of a matrix A using the command JordanDecomposition[A][[1]], and a decimal approximation of the orthogonal (or normalised) modal ...
5
votes
3answers
3k views

Local max/min of Mathematica data sets

Is there a way in Mathematica to find the local maxima of a set of points? Suppose you have ...
12
votes
4answers
1k views
13
votes
2answers
945 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
1answer
516 views

Adding ContourLabels changes contour colors?

I have an array s5 I want to plot using ListContourPlot ...
3
votes
2answers
197 views

TreePlot EdgeLabeling Style

I am trying to control the style for edge labels in treeplot and have run into a problem. Consider these two graphs: ...
3
votes
0answers
300 views

With comma as decimal separator, how do you insert a period in the header/footer?

I have enabled comma as my decimal separator, which means that comma still acts normally and when pressing period it will be converted to a comma. In the header I would like to make a period, so I ...

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