Whole-array arithmetic in Fortran

Elementwise math on entire arrays with not a loop in sight.

program vector_ops
    implicit none
    real :: raw(5) = [12.5, 8.0, 15.25, 6.75, 11.0]
    real :: net(5)

    ! Arithmetic on whole arrays, elementwise, no loop written.
    net = raw * 0.9
    print *, "net weights: ", net
    print *, "over 7 lbs:  ", net > 7.0
    ! Two arrays combine element by element the same way.
    print *, "difference:  ", raw - net
end program vector_ops

How it works

1. net = raw * 0.9 scales every element in one statement.
2. net > 7.0 is an array of logicals, printed as T and F.
3. raw - net combines two arrays element by element, same shape in, same shape out.

Keywords and builtins used here

• end
• implicit
• none
• print
• program
• real

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Step 1 of 3 in Whole-array thinking, step 10 of 27 in Language basics.

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