function swap_array, array

Sz=size(array)
N=Sz(1)

	CASE Sz(0) OF

2:	begin

ft1=make_array(size=size(array))

ft1(0:N/2-1, 0:N/2-1)=array(N/2:*, N/2:*)
ft1(0:N/2-1, N/2:*)=array(N/2:*, 0:N/2-1)
ft1(N/2:*, 0:N/2-1)=array(0:N/2-1, N/2:*)
ft1(N/2:*, N/2:*)=array(0:N/2-1, 0:N/2-1)

	end

1:	begin

ft1=make_array(size=size(array))

ft1(0:N/2-1)=array(N/2:*)
ft1(N/2:*)=array(0:N/2-1)

	end

ENDCASE

return, ft1


	end