## Dot_product

### Function Type:

Dot_product is a vector ( arrays of rank one ) intrinsic function.

### Function Purpose:

The function dot_product takes two vectors ( arrays of rank one ) and computes the dot
product of the two. This can be done on REAL, INTEGER, COMPLEX or LOGICAL
arguments.

### Required Arguments:

dot_product(** vectorA, vectorB** )

**VectorA **must be either an INTEGER, REAL, or LOGICAL array of rank one.
**VectorB** must be of the same type of VectorA.

### Optional Arguments:

There are no optional arguments.

### Results:

Lets say you have two arrays, a(3) and b(3). The values stored in array a are 1,6,-9 and
the values in array b are 3,-10,-7. If you need to find the dot_product of these two vectors
all you would have to do is type the following line of code.

X = dot_product(a,b)

Notice that the function outputs to a scalar. Remember from some previous course that
the result of the dot product operation is always a scalar. The results of this dot product
operation would be six ( (1*3) + ( -10*6) + (-9*-7) = 6 ).

### For additional information and examples see:

lecture thirty six

examples: matprod.f, speed.f, lsq3.f, and trapz2.f

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Written by Jason Wehr : jcw142@psu.edu and Maintained by John Mahaffy :
jhm@cac.psu.edu