# All Questions

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### Evaluation control inside Compile

I have the following function ...
90 views

### Can we compile this function/distribution?

I would like to compile this function to make it faster: ...
90 views

### How to compile or speed up a function with eigensystem?

I have defined two functions as following: ...
23 views

### Optimizing and Parallel Computing for Large Dyadic Intervals

I need help with the efficiency of my code i.e. less time so I can compute for large range of values. My function n[x] takes in a number x and outputs the ...
125 views

### Speed improvements and confusion for MapThread and Dot

I have a question / confusion over improving the speed of MapThread[Dot,...] for lists of tensors. My problem involves taking two lists of tensors and then ...
79 views

### How to compile properly for performance tuning

I have a question about how to compile functions properly for performance tuning. Currently, I am trying to solve an eigenvalue problem of a large matrix. Initially I just used the conventional ...
117 views

### Optimize Use of PeakDetect in Mathematica

I am quite new to Mathematica and I am looking for some advice in order to improve and optimize my code. Here is what I am trying to do: Open a stream Read the stream line by line and store it in "...
101 views

### Why won't nominally compilable function compile? (err Compile::cpintlt)

Context: I have millisecond timestamped sample data that I want to convert to a uniformly sampled series. This I do by padding each interval with repeated values (pbp ~ 'pad by position'}. The ...
62 views

### compiling matrix row assignment

I have this relatively simple code, generated with another Mathematica code (this is just an example): (edit: see below for simpler version) ...
72 views

### SystemException[“MemoryAllocationFailure”] with compile and speed issues

I am trying to run a code that gives out a matrix but, I seem to encounter some memory issues while trying to run it. The code is: ...
90 views

### How to speed up multiple calls of NonlinearModelFit?

I'm trying to do an insane amount of non-linear fits to large amounts of data sets. However, I found that the NonlinearModelFit is horribly slow. Here's the setup: ...
200 views

### How to speed up evaluation of expression (multiple variables) to gain speed? Compile?

I obtained some long expression and need to use them with a lot of different parameters inside a simulation. However, evaluation of the expressions is pretty slow, so that I would like to speed it up. ...
84 views

### Efficient compilation of a list of functions

Let's say that we have at our disposal nbfunc = 4; functions, whose exact expressions are gathered in the list ...
48 views

### Compile with “Listable” only on one argument

I would like to write a Compiled function which is listable only in the first argument, because this allow fast and easy parallelization. How is it possible to do it? In the following way it does not ...
65 views

### How can Distribution fitting be sped up?

The first line generates 1050 data points to fit. The second line fits this data to the same distribution. This takes about 100ms on my computer. Doing this with ...
167 views

### how to speed up this function?

in this code cumavg1,cumstd1,giuper1,gilower1 are compiled. however, i dont know how to compile ei and fi to further speed up the calculation. any help will be appreciated. ...
2k views

### Can this code be changed to run faster?

I've worked for several days trying to get this code to run faster. The imported data is 15MB. ...
137 views

### Efficiency in calculation on graphs: Compile?

Basic Question I have a looping calculation that I need to perform on some large lists a very large number of times, and as I have written the functions the computational speed is prohibitively slow. ...
290 views

### Mod slow in CompiledFunction

I've been playing with a little compiled Ising model implementation. It's brutally slow. Decomposing things I've found that the primary culprit appears to be Mod. ...
77 views

### How to boost the performance of a function that approximates a 3D object

I have defined a function $f_{a}(\boldsymbol{r})$ that gives a finite discrete approximation of a continuous function $f(\boldsymbol{r})$ that represents a 3D object. Here, the object is a sphere of ...
60 views

### Compilable table of Matrix diagonals function

1, I am trying to make Compilable function which takes Matrix of zeroes and ones f.e: ...
103 views

### Avoid hardcoding of variables for Compile by using a list

I want to automatically Compile an expression in between a routine of certain analytical manipulations. The number of arguments for the function may change for ...
68 views

### Is it possible to compile this code?

I'm not really familiar with the Compile function at Mathematica yet, but I know that it can, in some cases, be faster than using a non-compiled version of a code. I've been giving some shots in ...
160 views

### Debug numerical error inside CompiledFunction

I want to speed up evaluation time of a long expression (a function of a single parameter t). To do so, I thought about using ...
49 views

### Compile a precomputed list-type expression

I precompute an expression which takes pretty long to evaluate (i.e. for my real problem tmp[2] takes quite long) and I want to see if runtime can be improved using ...
320 views

### Random Geometric Graphs, but fast

I am optimising the random geometric graph generation ideas in this post. I need to generate a large number of random geometric graphs with probabilistic connectivity (soft random geometric graphs), ...
453 views

### Compile a program with Fold function

I have the following small program: ...
391 views

### Findroot with a precompiled function with parameters

If I want to precompile a function that I intend to put into FindRoot many times, I could do it like this: ...
185 views

### Making calculation of correlation dimension faster

I am trying to make my calculation faster. I was hoping, when I compiled it, it would work much faster, but in the end its even slower. I don't know if I am using ...
201 views

### Numerical Join of two sets of vectors ignoring repeats

I have two sets of numerical vectors which can be either Real or Complex and I want to combine them together, ignoring repeats. ...
339 views

### Using Findroot with Precompiled Function

I am writing a Monte Carlo algorithm to solve some algebraic equations. To do this I need to evaluate FindRoot many times on the same function. Following from F'x's answer to Expression evaluation ...
78 views

### Speeding up computation of a sequence

I am simulating the dynamics of a spring mass system impact an obstacle. I will not go into the details of the numerical scheme, but here are the general parameters and functions: ...
639 views

### Implementing a compilable Faddeeva function of complex argument

For those, who are looking at Halirutan's answer and thinking "gee, I wish I was that good at LibraryLink, then I could really speed up my code!" I leave here the ...
77 views

### Position with Compile is acting slower than without

For a big matrix 5000 x 5000 or list2 i am trying to get positions of all entries Except[1.0]. I am using ...
141 views

### Can I compile my function?

I'm trying to do some time-consuming simulations but I have no idea how to optimize this. ...
108 views

### Optimizing user defined graphicQ, test of graphicness of a sequence

A sequence of non-negative integers is graphic if it is the degree sequence of some simple graph. Graph realization problem is the decision problem where it is asked whether a given sequence is ...
98 views

### What is the most effective way to reassign values in an array based on their positions

I have to reassign values in a big array many times and it turned out to be the most time consuming in my program. The best way I could figure out is this ...
204 views

### Why is Compile + RandomReal faster than random real?

In the process of playing around with Compile, I discovered something surprising. RandomReal[{-1, 1}, 3] is a lot slower than <...
108 views

### Performance tuning with memoisation, compilation and vectorization - further possibilities?

In order to tune the performance of noticeably slow code of mine, I had a look at many different excellent posts on this topic here on M.SE, e.g. here to name the most interesting one. Now I ask ...
590 views

### Why is CompilationTarget -> C slower than directly writing with C?

Probably a hard question, but I think it's better to cry out loud. I've hesitated for a while about whether I should post this in StackOverflow with a c tag or not,...
102 views

### Compile function for NMinimize

I have a the following script, which essentially minimizes the function $h$ with respect to all the variables $a[\alpha][s][j][n]$, where $\alpha,s\in\lbrace0,1\rbrace$, \$j \in \lbrace ,\ldots,\text{...
170 views

### How to avoid AppendTo when computing similarities

I need to make the calculation of the HammingDistance for strings faster. The background is that I want to be able to compare the similarity of images of a textual ...
95 views

### How to deal with “Compile::cset” in Compile

When compiling below code Compile[{{data, _Integer, 2}}, Fold[Flatten /@ Flatten[Outer[List, ##, 1], 1] &, data]] I encountered error messages Compile::...
155 views

### How to use Compile? Bivariate Gibbs Sampler

I am trying to use compile to speed up my Gibbs sampler. I know I can use Reap and Sow to speed up tremendously. I have a more complicated Bayesian posterior that I want to speed up with compile so I ...
229 views

### Compiling in mathematica

I'm trying to compile what I think is a pretty simple function that does matrix multilplications in a loop (see below). But Mathematica issues the message: Could not complete external evaluation ...
135 views

### Table with programmatically specified number of iterators in Compile

Compare two ways of computing a table of values of a multivariable Gaussian: ...
289 views

### How to boost the performance of my own BSplineFunction

In my CAGD package, I implemented a CAGDBSplineFunction[] like built-in BSplineFunction[]. ...
132 views

### How to speedup Plot3D with precompiled argument

I have a huge problem with my code: I estimate it to take hours to run. The scheme of the code is the following (I left the steps the same, but took much simpler functions): ...