Questions about optimizing code for faster results, or how to do faster computations.

learn more… | top users | synonyms

10
votes
0answers
115 views

Exp is slower for some number ranges

I get a hit on performance with the Exp function depending on the range of my inputs. for example, with: ...
5
votes
0answers
208 views

Problems extending NelderMeadMinimize into 2D

Update The eventual route I followed was to adapt a version of the NM-simplex written in C and link to it with MathLink. Once I've tested this out fully I'll post it here. I've been playing around ...
5
votes
0answers
84 views

Is there something like MaxProcessorUsed?

For standard procedures it is easy to test if the implementation is better or worse than other by using Timing etc. It does not help us with creating ...
3
votes
0answers
134 views

Module in numerical model for NonlinearModelFit is slow and leaks memory

I am trying to make a NonlinearModelFit where the model is the result of a numerical calculation. My code works, but it is very slow and also seems to have a memory ...
2
votes
0answers
75 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 ...
2
votes
0answers
59 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 ...
2
votes
0answers
221 views

Taking real and imaginary parts of indexed functions and speeding up ComplexExpand

I am setting up a large system of ODEs and in order to use the IDA method (which is sig. faster for my system and thus attractive), I must split my equations into real and imaginary parts. I am ...
2
votes
0answers
100 views

Frontend cursor movement speed depends on the position in large notebook file

I run Mathematica v9 on my Atom laptop (don't ask) and I got used to the fact that everything is slower. Except for one annoying thing: cursor movement (in text) is slower than the keyboard key repeat ...
2
votes
0answers
192 views

Project Euler (memory and speed issues)

Let n be a positive integer. An integer triple (a, b, c) is called a factorisation triple of n if: 1 ≤ a ≤ b ≤ c a·b·c = n. Define f(n) to be a + b + c for the factorisation triple (a, b, c) of n ...
1
vote
0answers
82 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 ...
1
vote
0answers
81 views

Increase optimization processing speed

As you know, sometimes numerically solving of optimization problems takes several minutes. For this reason 2 question came up to me: 1 - When one is abort the optimization procedure, how it is ...
1
vote
0answers
124 views

Is there a way to speed up Simplify and/or PolynomialReduce Modulus-> 2?

I'm trying to simplify a series of equations with at most 64 input terms. As the number of terms involved in the equations increase, the runtime seems to grow exponentially. Does anyone know of ways ...
1
vote
0answers
610 views

Speed up Numerical Integration

EDIT: I need to evaluate a very complicated multi-dimensional Integral. The dimension of the Integral depends on a variable j. Let's make my point clear with the ...
0
votes
0answers
91 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. ...
0
votes
0answers
69 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
0answers
80 views

How to save the results in an identical Excel file (.xls) in each iteration of a Do loop

Assume the following code (Below code is just an example to clearly illustrate my problem): ...
0
votes
0answers
142 views

Speeding up inversion of symbolic matrices by invoking caching

Is it possible to reduce the computation time taken to find inverse of symbolic matrices USING CACHING TECHNIQUES accessible (if any)? I am trying to compute inverse of symbolic matrices of size ...
0
votes
0answers
60 views

Is there a faster way to do Normal[SparseArray[{{1,1,1}→1.2, {1,1,2}→20.2, …, {m,n,p}→0.3}]]?

I have a list of the form {{1,1,1}→1.2, {1,1,2}→20.2, ..., {m,n,p}→0.3} and I want to create an $m \times n \times p$ array, $A$, where the value of $A[[i,j,k]]$ is ...
0
votes
0answers
73 views

Speeding up Integrate and the numerical solution

I want to compute the drag of a plate Below is the code I am using to integrate the function ...
0
votes
0answers
146 views

Code performance problem

Could anyone help me with the attached code? How would you speed up my attached code in some degree? Your comments are highly welcome. ...
0
votes
0answers
131 views
0
votes
0answers
283 views

Performance in parameter estimation from ParametricNDSolve using varied initial conditions

I have 250 data points from a timecourse exeriment in a list, with columns specifying (1) time, (2-4) initial conditions, (5) absorbance reading. I want to fit 4 parameters (k1, k2, k3, k4) in a DAE ...