Questions on optimizing Mathematica code for higher performance. This may mean faster execution, lower memory usage or both. Not to be confused with mathematical optimization.

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0
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1answer
97 views

Unusual Slow Down with LocatorPane/DynamicModule

I have coded up a little interactive DynamicModule to help me with image processing/segmentation of stacks of timelapse microscopy images. I am experiencing a crippling slow down in the ...
2
votes
0answers
85 views

An efficient way to merge a pair of 4d arrays of non regular length lists

Question I have two 4 dimensional non regular length lists of complex values. I have working code however it seems quite slow and I am not sure how I could improve this. Mathematically I am trying ...
7
votes
1answer
184 views

How do I speed up a plotting of NIntegrate when repeated multiple times inside Plot?

I am studying a set of functions (many of which I know only as a definite integral) and I have assembled into a list. Here is a sample: ...
6
votes
1answer
228 views

Optimizing the front end on the Raspberry Pi

Using Mathematica's Front End on the Raspberry Pi is truly a test of one's patience. The most basic of notebooks become unresponsive after seemingly trivial additions to the notebook. Consider the ...
2
votes
2answers
115 views

Improving the speed/efficiency of multiple (finite range) convolutions for a causal response plot

So I am looking at modelling the response of a system that is excited by multiple pulses over a period of time. The way to find the response at time t is to take the convolution between the impulse ...
1
vote
1answer
78 views

Faster code for solving an equation with parameters

I am new to Mathematica and wanted to solve an equation that depends on parameters. The code is below ...
4
votes
2answers
196 views

Time-efficient creation of matrix

I have expressions like xx1=FF[1, 1] GG[1, 1] + FF[1, 1] GG[2, 2] + FF[2, 2] GG[2, 2] xx2=2*FF[1, 2] GG[1, 1] + FF[1, 1] GG[1, 2] + FF[2, 2] GG[2, 2] and I want ...
18
votes
1answer
1k views
2
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1answer
231 views

How can I reduce computation time while still obtaining a good approximation for my function?

I am new to any CAS (and Mathematica, for that matter) and new to StackExchange too, so forgive me and correct me on any mistakes. I have this function: $J_p=\sum_{m,n=1}^{\infty} ...
8
votes
1answer
294 views

Why do Tooltips slow down Dynamic so much? Is there a faster alternative?

I'm working on a Dynamic ListPlot with a few thousand plots, and it seems that wrapping the points with Tooltip slows the Dynamic responsiveness substantially. With the simple example below, dragging ...
8
votes
2answers
385 views

Finding all sets of elements with two common elements in a large dataset

I have a very large network of atoms ($\approx 10^6$ atoms) with fixed positions that resemble a cellular structure: I have two files including: fixed locations of each atom set of points which ...
22
votes
1answer
506 views

How to work with Experimental`NumericalFunction?

This question is intimately connected with previous one: "How to create internally optimized expression for computing with high WorkingPrecision?" Oleksandr R. correctly states in the comment: A ...
28
votes
1answer
1k views

Mma 10: Half the parallel power (Macs)?

Here is a comparison of the parallel kernels launched under Mathematica under v9 and v10, on the same identical current 2014 R2-D2 Mac Pro ... [ Update: Valerio has commented that the same issue ...
3
votes
1answer
167 views

Why is my compiled code slower?

I am trying to make a Mathematica program run faster. Here is part of the original version. It takes as input the integers X (of order 100), J (of order 10000), and n (of order 100), the real number p ...
1
vote
0answers
223 views

Speeding Up Image Processing Functions

I am working with stacks of 1024x1024 timelapse microscopy images that I am performing a series of image processing functions on to help segment each image. These functions include ...
1
vote
1answer
290 views

Performance of compiled functions (Project Euler No14)

I was playing around with the project euler problem 14. The solution I came up with is listed below as cf1. The solution works fine but I get the compiler warning: ...
0
votes
0answers
145 views

Improving the speed of evaluating Table with nested functions

I am a Mathematica novice working with a stack of 1024 x 1024 WatershedComponents (or MorphologicalComponents) label matrices ...
8
votes
4answers
434 views

Fast method to select matrix elements based on a vector of positions

There is an operation for which I have long wanted to find a better solution. Let: a be a matrix of dimensions $m\times n$ ...
2
votes
0answers
132 views

Mathlink program with low cpu usage on linux machines only

Question I am incorporating some c++ code via Mathlink into my simulations in Mathematica. My questions involves the execution efficiency of the c++ code on different machines. For example, on my ...
7
votes
1answer
298 views

Porting code from MATLAB

I'd like to switch from MATLAB to Mathematica for my research in digital signal processing. I used Mathematica a lot during the '90s but I haven't used it since then, so I might as well be a complete ...
1
vote
1answer
67 views

A code deal with Lists operation ---Needs optimizion

I have written some code to deal with lists, But the speed of the code is slow, Could Someone help me to speed up it? Probably could rewrite it with Functional Programming! Give me some ideas! The ...
0
votes
0answers
85 views

strange timing behavior

The following code is from a book about Mathematica. ...
2
votes
3answers
165 views

Speeding Up Replacing of Labels in Large Matrix?

I am Mathematica novice and am trying to find a fast way to replace labels in some rather large matrices (512x512 or 1024x1024) that have resulted from segmenting images with WatershedComponents or ...
6
votes
1answer
204 views

Why is AllTrue much slower than VectorQ?

This seems to be a theme with V10, a new function dedicated to a specific task doesn't live up to expectation performance-wise. Mr. Wizard has already uncovered 2 such functions here and here. So how ...
4
votes
1answer
129 views

Example from Mathematica documentation (ExtremeValueDistribution) seems to be evualting “forever”

I am referring to this example at the reference page for the extreme value distribution: http://reference.wolfram.com/mathematica/ref/ExtremeValueDistribution.html#6764486 The first three commands ...
1
vote
0answers
265 views

Speeding up NDSolve for system of differential equations

I am wondering if there is a way to speed up this function that solves a system of ordinary differential equations with NDSolve? Thus far I've tried specifying a few different methods such as LSODA, ...
1
vote
1answer
108 views

Warning and Errors during Compile

I defined a compiled function cf = Compile[{{x, _Integer}, {n, _Integer}}, z = (n^x); Binomial[n, #]* StirlingS2[x, #] *(#!)/z & /@ Range[x]]; and I ...
2
votes
3answers
83 views

Reduction of repetitive calculations in Table

If I generate two tables inside a function which are function[n_, x_, y_]:=( table1 = Table[i* x/n^x, {i,1,n}]; table2 = Table[i* y/n^y, {i,1,n}]; ) where ...
12
votes
1answer
441 views

the more effective method to find 21 digits armstrong number

In recreational number theory, a narcissistic number (also known as a pluperfect digital invariant (PPDI), an Armstrong number(after Michael F. Armstrong) or a plus perfect number) is a number that is ...
25
votes
5answers
652 views

Compiling ColorFunction for faster complex phase-amplitude plots

I have gotten into the habit of plotting complex-valued functions on a plane using a color-function along the lines of ...
4
votes
3answers
221 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 ...
0
votes
0answers
108 views

Complex Convolution

I am attempting to integrate a convolution variable using the following code. However, the program is taking too long to complete the integration. Does anybody have any coding tips that may make ...
0
votes
0answers
101 views

Timing: how make a program to work faster using built in functions and tables

I want to improve my code to make it working faster even for very large numbers. ...
67
votes
2answers
5k views

Shaving the last 50 ms off NMinimize

The epilogue: A paper where the below answer is used was published. The answer below is cited among the references:) The background: I have to fit an objective function for ~10 000 datasets in near ...
5
votes
1answer
233 views

More efficient Omnibus number determination?

Amusing myself with concepts from "Omnibus Sequences, Coupon Collection, and Missing Word Counts", in particular the sequences. To paraphrase the concept, a string is k-Omni over some alphabet a if ...
2
votes
2answers
202 views

Alternative for MapThread in listable functions

How can I rewrite this more efficiently taking advantage of flo, dem, and Nsup being ...
1
vote
1answer
100 views

How can I speed up this multi-equation Solve problem?

I'm trying to solve a set of equations (chemical kinetics for a complex system, but don't worry about that). I ran it for 24 hours and I got no output. Here is the relatively simple code (I want to ...
0
votes
0answers
29 views

Speed up series expansion [duplicate]

I have a rather complicated function that I need to expand it in series, which is quite straightforward but takes a long time. I was wondering if there is a way to speed up such a calculation: ...
3
votes
2answers
408 views

How to speed up minimization of function

I have the fallowing code (the functions within that code are replaced by simpler ones, but the code structure is identical): $$$$ ...
7
votes
4answers
269 views

Position of Subsets in a List

I have a particular list of integers and a matrix whose entries are lists. Say I know that my particular list is a subset of at least some of the elements in the matrix. I want to find an efficient ...
1
vote
0answers
52 views

Understanding Mathematica: How to write fast code? [duplicate]

I'm relatively new to Mathematica but have done a few projects using it so I'm quite comfortable with the syntax and the basic functions available. Since I've had programming experience in the past I ...
1
vote
0answers
107 views

Speeding up the numerical integration of a certain function

I'm using the following function f[t_] := 3/4 t^-3 NIntegrate[(x^4*Csch[x/2]^2), {x, 0, t}, Method -> {Automatic, "SymbolicProcessing" -> 0}]; I ...
26
votes
3answers
1k views

Smooth Peter de Jong attractor

Today I was playing with Peter de Jong attractor. At the bottom of the page I've linked there are beautiful examples like: My attempts are not so great: It is around 10^5 points. For more than ...
1
vote
1answer
152 views

Speeding up a function

This is un updated version of a previous (now deleted) post of mine. I need to marginalize a distribution. I was suggested to use the code in this thread. This works just fine, but the problem is ...
22
votes
1answer
2k views

Why won't Parallelize speed up my code?

What reasons are there that can cause parallelized Mathematica code not to run with full performance?
1
vote
2answers
212 views

More efficient implementation for comparing coefficient lists in a Do-loop

I'm wondering how to speed up the following code so it actually computes for $n=2$: ...
0
votes
0answers
82 views

Timing Differences

In More efficient implementation for comparing coefficient lists in a Do-loop link, george2079 posts in his first answer a piece of code that takes 352 seconds to compute. When I run this same piece ...
0
votes
2answers
137 views

Make an effective projection of matrix

To best explain my problem, I will take the following example: Consider the following matrix : ...
12
votes
5answers
459 views

How would you efficiently implement BinListsBy?

Let's say I have a list like this: data = {{21, "Alice"}, {27, "Bob"}, {22, "Charles"}, {34, "Dora"}, {75, "Eliza"}} containing ages and names of persons. What I ...