FORTRAN-将数组值分配给变量

Question

Is there a way to get the value of an array to the shape of a variable? Even when I select a single value of an array, say A(1:1, 1:1) , it still complains when I compile and want to assign this to a variable:

Error: Incompatible ranks 0 and 1 in assignment at (1)

The goal in the end is something like this:

H = MAXVAL(matrix) - epsilon
IF ( matrix(i:i, i:i) >= H ) THEN

... but I cannot make this comparison because H is a variable and matrix(i:i, i:i) a 1x1 array. Is the only possibility for this to work to make H and array, too?

Thank you for your help!

Answer 1

Do not specify a range, use a single element:

A(1,1)=1

Your statement would then read:

H = MAXVAL(matrix) - epsilon
IF ( matrix(i, i) >= H ) THEN

Background:

Fortran allows you to work on sub-arrays like:

A(1:10,2:5)

which would be a 10x4 array. So A(1:1,1:1) is in fact an array (1x1) (as you noted). A(1,1) , on the other hand, is a scalar and can be treated as such.