如何用特定范围的随机数填充矩阵的列? [英] How to fill columns of a matrix with random numbers of specific range?

问题描述

我有一个矩阵100*10.现在的目标是用特定范围内的随机整数填充矩阵的每一列.现在的问题是每列的随机数范围都会变化.例如，对于第一列，范围是[1,100]，对于第二列，范围是-10 to 1，依此类推，直到第10列.

I've a matrix of order 100*10 . Now the objective is to fill each columns of the matrix with random integer within a specific range. Now the problem is for every column the range of the random number changes. For instance, for the first column, the range is [1,100] , for the second its -10 to 1 and so on till 10th column.

这是我尝试过的:

b = [0,100;-10,1;0,1;-1,1;10,20]
a = []
for i=1 to 10
    a[] = [(i:100)' randi(1,100)]
end

如何生成这种形式的矩阵?

How do I generate a matrix of this form?

推荐答案

我目前尚未安装matlab，但我会做类似的事情.

I don't have matlab installed right now, but i would do something like this.

m = 100;
n = size(b, 1);
range  = b(:, 2) - b(:, 1);
offset = b(:, 1);

A = round(bsxfun(@minus, bsxfun(@times, rand(m, n), range), offset);

没有循环，它将变为:

M = 100;
N = size(b, 1);

A = zeros(m, n); % preallocate to avoid matrix expansion
for ii = 1:n
    A(:, ii) = randi(b(ii,:), m, 1);
end

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