How can I generate a variably-sized matrix of random values in MATLAB?

How can I generate a random matrix with 开发者_开发技巧more rows than columns? For example, with the number of rows being a multiple of the number of columns, like 10 columns 500 rows, or 20 columns 1000 rows, etc...

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You can do these sorts of things using functions like RAND and RANDI. For example:

nCols = randi([10 20]);   %# A random integer between 10 and 20
nRows = nCols*50;         %# Number of rows is a multiple of number of columns
mat = rand(nRows,nCols);  %# A matrix of random values between 0 and 1