F116 Scalar Product of Two Space-Time Vectors

Function subprogram DOTI computes the scalar product $a.b$ of two space-time vectors
$(a$₁,a₂,a₃,ia₄) , $(b$₁,b₂,b₃,ib₄) , where $i=-1$ , i.e.

$a.b\; =\; a$₁b₁+a₂b₂+a₃b₃-a₄b₄.

Structure:

FUNCTION subprogram
User Entry Names: DOTI

Usage:

In any arithmetic expression, DOTI(A,B)

has the value $a.b$ .

A,B

( REAL) One-dimensional arrays of length 4, containing $a$_j,b_j,(j=1,2,3,4) , respectively.

F117