🚀 go-pugleaf

In article <1993Jan8.134612.18468@news.unige.ch>, pfennige@scsun.unige.ch (PFENNIGER Daniel) writes:
> 
> Is it true that a Fortran-90 programme inverting matrix A would be:
>       B = 1./A
> ?

No; it is important to keep in mind the model that Fortran 90
does _array processing_, not matrix arithmetic.  1./A produces
an array with the same shape of A in which each element is
the reciprocal of the corresponding element of A.  Similarly,
A * B is element-by-element multiplication, not matrix
multiplication.  In Fortran 90, MATMUL(A, B) is an intrinsic
function, but there is no inversion intrinsic.

However, in Fortran 90 it is possible to define a new data type,
called "MATRIX", say, and define A * B to be matrix multiplication
and perhaps a unary operation .INVERSE.
-- 
Walt Brainerd                walt@netcom.com
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