Questions about the generation and use of compiled functions using Compile.

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67
votes
6answers
5k views

List of compilable functions

Is there somewhere a list on the functions that Compile can compile, or the cases in which a particular function can be compiled that I haven't found? I'd be glad ...
80
votes
5answers
6k views

How to compile effectively?

What are the best practices of compiling functions? I understand that this is a vague question, but let me list some aspects that might trigger useful answers. Some of these have already been answered ...
40
votes
2answers
2k views

Internal`Bag inside Compile

Since Internal`Bag, Internal`StuffBag and Internal`BagPart can be compiled down, it is a ...
24
votes
4answers
939 views

Compiling more functions that don't call MainEvaluate

I would like to use Compile with functions defined outside Compile. For example if I have the two basic functions F and G F[x_] := x + 2 G[x_] := x And I want ...
33
votes
4answers
2k views

How well does Mathematica code exported to C compare to code directly written for C?

Essentially what it says in the title. Mathematica can, IIRC, export it's code to C. How much overhead does that inflict on the code, as compared to writing it from scratch in C?
41
votes
4answers
2k views

Speeding up this fractal-generating code

I used the code below (which is a sample from this gist containing more similar code) in my answer to my own question about Mandelbrot-like sets for functions other than the simple quadratic on ...
14
votes
2answers
633 views

Efficiently collecting results inside a compiled function

When we don't know the number of results that will be generated, the usual way to collect results is Reap/Sow. Another ...
7
votes
0answers
231 views

Compile recursive function modifying global variables

How to compile recursive formula when it relies on more than a few global variables (global to the topmost compiled function)? It is unreasonable to pass on all such variables to each recursive ...
10
votes
1answer
296 views

Using Apply inside Compile

In this great answer a compiled version of the Nelder-Mead algorithm is presented. Since it works on arbitrary dimensions (i.e. arbitrary number of arguments), it has to use apply on the objective ...
9
votes
1answer
400 views

Example program for calling Mathematica from C

I want to call Mathematica from a C program. Suppose I have two numbers x =2 and y=3. I want to define the x, y in a C program and call Mathematica and I want Mathematica to do the sum and return me ...
12
votes
2answers
179 views

How do you determine the optimal autocompilation length on your system

When you pack lists there is an overhead therefore packing a list with, say, 2 elements is likely to cost more than you get back in efficiency. Mathematica has default list lengths for which functions ...
11
votes
1answer
320 views

Why is MainEvaluate being used when LinearSolve can be compiled?

According to this question LinearSolve can be Compiled. However, CompilePrint shows a MainEvaluate but no-warning is generated. It appears that LinearSolve is not ...
4
votes
3answers
178 views

How to compile a diagonal array efficiently?

For example, if we use some functions defined prior to Compile, we usually have the main evaluators in the compiled codes, pointing to the definition of the ...
-5
votes
3answers
1k views

Problem with Compile Function

I am attempting to Compile this function which is used to calculate a elastic collision in two dimensions. The two first coordinates of each list are the position ...
10
votes
1answer
233 views

Bizarre behavior of With, Compile and Break

I'm guessing this is almost certainly a bug in Compile (because they're fairly common), but it's pretty weird and I spent about an hour tracking down the issue and ...
12
votes
2answers
442 views

How can I compile this function

I want to simplify my function f1 to f2, but f2 can't be compiled. How can I make it ...
12
votes
1answer
285 views

Removing calls to MainEvalute when using inlined compiled closures

This question is tightly related to the answer Shaving the last 50 ms off NMinimize. There @OleksandR shows how inlined closures can be used to eliminate calls to ...
15
votes
1answer
653 views

What technical obstacles prevent all Mathematica code compiling to C

The following represents an attempt at a very simple view of the levels in Mathematica code: We have had lots of questions about deployment and compiling Mathematica code to C. Some of these for ...
14
votes
2answers
191 views

Third argument of Compile

In his last comment on this answer, halirutan shows an example in which the third argument of Compile does not have any effect. The example is as follows. ...
13
votes
3answers
374 views

Quick multiple selections from a list

What is the fastest way to make multiple selections from a list? Compiled methods included. For example, here are two methods for selecting a subset, compared:- ...
13
votes
2answers
766 views

Speeding up random walk for many particles

I am trying to speed up this code for many particles to take a random walk. I'm not sure why it is so slow for such a simple task. I got a few hints from colleagues to reduce the precision of the ...
6
votes
1answer
569 views

Using a compiled function inside NIntegrate gives “CompiledFunction::cfsa” message

The following function is defined for Real input: FFc = Compile[{{x, _Real}, {EF, _Real}},If[x > EF, 0., If[x == EF, 0.5, 1.]]] FFc is now used in the ...
14
votes
1answer
266 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 ...
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 ...
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 ...
4
votes
1answer
617 views

Creating a standalone (executable) from mathematica code

I have written a small mathematica code to input a ".csv" file and output the data in a specific format, in a ".txt" file. I would like to give this program as an executable to my friend as she ...
4
votes
1answer
272 views

CompilationTarget->“C” crashes the kernel

Major deviation from my original post I realize that the long code I originally had was very discouraging to debug and did not attract any answers. So I have decided to revamp this question ...
1
vote
1answer
203 views

Compile with array operations

When I use the function f with only the Module ...
17
votes
3answers
657 views

How to force Compile to return multiple results?

I would like to return two separate values from a compiled function, but Mathematica refuses to use the compiled version. Here is a narrowed-down example: ...
10
votes
2answers
223 views

Avoiding MainEvaluate in a CompiledFunction to fetch global variables

I'm trying to write a simulation using Mathematica 8.0. Since I will most likely be doing the same operation over and over again, I'm trying to Compile whatever I ...
14
votes
1answer
2k views

How do I get Mathematica to recognize a C compiler on a 64-bit Windows machine?

Mathematica does not recognize any C compiler on my computer. I run Mathematica 8.0.4.0 on Windows 7. I've tried to make sure various C compilers are installed on my computer, but I'm not sure how to ...
13
votes
1answer
276 views

Using Boost with CreateLibrary

I was looking at the answer of Leonid of Faster alternatives for DayOfWeek and wanted to see how hard it would be to do something similar in C++ using an external library like Boost. I tried to ...
12
votes
1answer
140 views

In Compile “InlineExternalDefinitions” doesn't work anymore in Mma v10 like in v9

In Mma 9 using CompilationOptions -> {"InlineExternalDefinitions" -> True} inside of Compile inlined the values of the ...
9
votes
1answer
141 views

How to avoid CopyTensor in CompiledFunctions?

In a reply here Leonid wrote, “Compile can handle a number of higher-level functions, such as Transpose, Partition, Map, MapThread, etc. Most of these functions return expressions, and even though ...
11
votes
1answer
860 views

How to install and configure Intel C++ Compiler for Mathematica correctly?

I wish to try the trial version of the latest Intel C++ Compiler for Windows with Mathematica. I have downloaded the current version of Intel® C++ Composer XE 2011 for Windows and installed only the ...
11
votes
1answer
245 views

Is it possible to use Compile on a function with optional arguments?

My Mathematica is a little rusty, so apologies in advance. I think my problem is quite simple, but I can't seem to find the answer on my own! Simple example : ...
11
votes
3answers
724 views

Function does not compile with Greater in it

I have to speed up a matrix-calculation and would like to use Compile for it, though it fails and produces an unknown error message: ...
8
votes
2answers
290 views

Goto and Compile

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7
votes
1answer
250 views

Compiling Map over expression that yields a ragged array

I'm trying to speed up a function that looks in the neighborhood of each 3D point in a large dataset and finds all the points within 1 unit in each direction, x, y, z. I've started by using ...
5
votes
2answers
2k views

How to use a matrix variable for a compiled function

I want to compile the following function which takes a matrix variable. ...
14
votes
2answers
1k views

Fastest way to measure Hamming distance of integers

I am looking for a fast and robust way to calculate the Hamming distance of integers. The Hamming distance of two integers is the number of matching bits in their binary representations. I expect that ...
12
votes
2answers
478 views

Using Goto and Label in compiled function?

Below I post some rudimentary code to show that there is something wrong using Goto and Label commands in compiled functions (or I believe there is something wrong). It seems that the command Label is ...
8
votes
1answer
244 views

How to compile Heike's winding number function?

Heike gave the following function for winding number: ...
3
votes
1answer
202 views

Need help with C Code Generator

I'm trying to use the Mathematica C Code Generator package to generate code that is to be included in a web application by a developer. I don't know any C, and this seems to be the only way to ...
10
votes
1answer
193 views

Unexpected behavior of Compile, Return and ;

Could somebody explain why test = Compile[{{x}}, Return[x]; ]; test[0.] returns ...
6
votes
1answer
254 views

How to compile Map and MapAt

I have a long list (say, million of elements, like this one: {{{1.0, 2.0}, 3}, {{4.0, 5.0}, 6},...} I would like to compile a function ...
9
votes
0answers
142 views

Compile not correctly initializing a variable defined inside Module

In the following example, inside the minimumX's Module, x is initialized to 1, but the ...
7
votes
2answers
628 views

Working with large data, pass-by-reference, compiled functions

I think I know the answer to this, but after two days of Googling, this is my last effort before going down an unwanted path... I have a function that takes lots of large data as arguments as well as ...
6
votes
1answer
209 views

If doesn't compile if its output is the output of Compile?

The smallest sample I can find to reproduce this problem is: test = Compile[{}, If[True, 1]]; << CompiledFunctionTools` CompilePrint@test ...
5
votes
1answer
66 views

Unequal and Compile

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