How can I simplify/vectorize this nested loop version of pascals triangle?
显示 更早的评论
%mypascal
n = input('Enter a value for n: ');
% create matrix using nested loops (programming method)
somemat = ones(n);
for i = 2:n
for j = 2:n
somemat(i,j) = somemat(i-1,j) + somemat(i, j-1);
end
end
2 个评论
Stephen23
2018-6-12
@Mark Nelson: is there a specific problem with using a loop?
Mark Nelson
2018-6-12
采纳的回答
OCDER
2018-6-12
2 个评论
Mark Nelson
2018-6-12
OCDER
2018-6-12
Yeah, I don't think you can vectorize it completely, otherwise Mathwork's pascal would have shown the vectorized code. Since the pascal triangle is symmetric, you could vectorize the filling of the other half of the triangle, which will speed up the code.
For n = 2000, pascal.m is ~ 5 times faster than your pure for loop approach.
更多回答（0 个）
类别
在 帮助中心 和 File Exchange 中查找有关 Loops and Conditional Statements 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 
