Vector products: Difference between revisions

=={{header|Fortran}}==

{{works with|Fortran|95}}

Specialized for 3-dimensional vectors.

<lang fortran>program VectorProducts

real, dimension(3) :: a, b, c

a = (/ 3, 4, 5 /)

b = (/ 4, 3, 5 /)

c = (/ -5, -12, -13 /)

print *, dot_product(a, b)

print *, cross_product(a, b)

print *, s3_product(a, b, c)

print *, v3_product(a, b, c)

contains

function cross_product(a, b)

real, dimension(3) :: cross_product

real, dimension(3), intent(in) :: a, b

cross_product(1) = a(2)*b(3) - a(3)*b(2)

cross_product(2) = a(3)*b(1) - a(1)*b(3)

cross_product(3) = a(1)*b(2) - b(1)*a(2)

end function cross_product

function s3_product(a, b, c)

real :: s3_product

real, dimension(3), intent(in) :: a, b, c

s3_product = dot_product(a, cross_product(b, c))

end function s3_product

function v3_product(a, b, c)

real, dimension(3) :: v3_product

real, dimension(3), intent(in) :: a, b, c

v3_product = cross_product(a, cross_product(b, c))

end function v3_product

end program VectorProducts</lang>