How to optimize the following function
显示 更早的评论
Hello everyone:)
It's somewhat a crosspost from stackoverflow http://stackoverflow.com/questions/21146693/sensibility-of-converting-matlab-program-in-java-to-improve-performance. We try to develop a genetic algorithm approach to find a solution to the sudoku game. We've noticed that the code takes too long to calculate one generation and after profiling it found out that the following function takes most of the time, the hotspot (as expected) is the call to
intersect(s,board(i,:))
I think it's because it runs in a loop. Is there a non-loop alternative to compute the difference. Basically we want to find out how many duplicates each row have (in the range of possible values from 1 to 9). Here is the code:
%%%used this code to make a post on stackoverflow
%http://stackoverflow.com/questions/21146693/sensibility-of-converting-matlab-program-in-java-to-improve-performance
function [fitness, finished,d, threshold]=fitness(population_, n)
finished=false;
threshold=false;
V=ones(n,1);
d=zeros(size(population_,2),1);
s=[1:1:n];
for z=1:size(population_,2)
board=population_{z};
t=0;
l=0;
for i=1:n
l=l+n-length(intersect(s,board(:,i)'));
t=t+n-length(intersect(s,board(i,:)));
end
k=sum(abs(board*V-t));
f=t+l+k/50;
if t==2 &&l==2
threshold=true;
end
if f==0
finished=true;
else
fitness(z)=1/f;
d(z)=f;
end
end
end
Thank you loads
采纳的回答
Walter Roberson
2014-1-17
histc(V, 1:9) > 1
you can then any() that if you just want to know if there are duplicates at all, or you can sum() it if you want to know how many distinct digits have duplicates.
Or you could experiment with the timing of sparse(V, 1, 1) > 1 and of accumarray(V(:), 1) > 1
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Sudoku 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!
Translated by 
