SPREAD(SOURCE,DIM,NCOPIES)
This function replicates an array by adding NCOPIES of in the direction of a stated dimension.
For example, if A is (/5, 7/), then
As DIM= 2 the vector (/ 5, 7/) is spread along dimension 2 (the direction of a row).
In this case DIM= 1 so the vector (/ 5, 7/) is spread
along dimension 1 (the direction of a column).
A good use for this intrinsic is during vectorisation when, say, a doubly nested DO loop is combining a vector with each column of an array at the centre of the loop, the statement can be rewritten as a 2D array assignment by creating a copy of the vector for each column of the array. For example,
DO i = 1,100
DO j = 1,100
A(i,j) = B(i)*2
END DO
END DO
can be transformed to
A(1:100,1:100) = SPREAD(B(:),2,100)*2
which exploits Fortran 90 array syntax.