Convert an array of logical type to an array of integer/double type -

i using silverfrost ftn95 and, since not expert, need create function takes input array of logical variables , returns array of integer variables, 0 false , 1 true. wrote simple code semplify how tried implement it:

program main logical, dimension(2,1)     :: integer, dimension(2,1)     :: b integer, dimension(2,1)     :: toint a(:,1)=.false. b=toint(a) write(*,*)b end program  function toint(log) result(val) logical, dimension(2,1), intent(in)     :: log integer, dimension(2,1)                 :: val i=1,2     if (log(i,1))         val(i,1) = 1     else         val(i,1) = 0     end if end end function 

this code gives me error: integer expression expected in array bounds subscript, variable 'a' not have integer type (at line "b=toint(a)"), , can't find error is. suggestions or other ways solve problem helpful. thanks

the error message comes because in program main you've declared toint array, statement toint(a) interpreted attempt index array using logical a. think you've declared toint external function returns integer array, you've not given compiler enough information make connection function definition.

you fix removing misleading declaration of toint program, moving line end program end of source file, , inserting line contains have end program. these steps make toint internal , compiler take care of matching calls function itself.

but think there 3, possibly more, better ways, have.

one write along lines of

integer, dimension(x,y) :: a,b,r logical, dimension(x,y) :: m  ! set elements of m wish  = 1 b = 0  r = merge(a,b,m) 

which assign r values a m .true. , b m .false. doesn't matter x , y are, array arguments merge conformable. should relatively easy turn function repeated use.

secondly, use where statement, perhaps this

r = 0            ! elements set 0 where(m) r = 1   ! m true, r set 1  

this approach dispenses a , b.

thirdly investigate writing elemental function operates on scalars , on arrays of rank. i'll leave 1 exercise. requires modification function have, operates on scalars , not on fixed-size arrays. third approach best - straightforward, flexible, easiest program.