Please help me in generating a random string(row vector) in which each element has a different upper bound.

For example, I want to generate a row vector A randomly

A = [ 4 2 6 1 5 ];

Whose elements are bounded by an upper bound

UB = [ 5 4 6 3 5 ]

E.g. the first element of A can take any integer value between [0 – 5] and second element can take any integer value [0 – 4] and similarly other elements are bounded.

Now from this row vector 'A', N (length (A)), new vectors are to be generated. In each vector, an element of the vector A changes the value randomly within the upper bound and rest of the elements remains same. For example, for above vector A

A = [ 4 2 6 1 5 ];

New vectors are

A1 = [ 3 2 6 1 5 ];
A2 = [ 4 1 6 1 5 ];
A3 = [ 4 2 3 1 5 ];
A4 = [ 4 2 6 3 5 ];
A5 = [ 4 2 6 1 2 ];

Please help. Thanks in anticipation!

Answer 1

[Massimo Zanetti]

The useful way is

U = [2,3,4,5,7];
A = arrayfun( @(x) randi([0,x]) , U )

but, if upper-bounds are 1-digit numbers, you can lighten the procedure by generating one random integer between 0 and N, where N is the number obtained by merging your 1-digit upper bounds. An example:

%your input
U = [5,4,6,8,6];
%merge digits
N = str2double(char(U+'0'))
%get random number between 0 and N
An = randi([0,N])
%get a vector of An digits
A = num2str(An)-'0'

N = 
  54686
An =
  34015
A =
  [3 4 0 1 5]

NOTES:

1. this only works if upper-bounds are 1-digit numbers!
2. you must treat appropriately leading zeros in A, e.g., if

A = [2,3,4]

you must get to

A = [0,0,2,3,4]