face_normal4 – VecFor

public elemental function face_normal4(pt1, pt2, pt3, pt4, norm) result(normal)

Calculate the normal of the face defined by 4 points.

The convention for the points numeration is the following:

 3.----------.2
  |          |
  |          |
  |          |
  |          |
 4.----------.1

The normal is calculated by the cross product of the diagonal d13 for the diagonal d24: d13 x d24. The normal is normalized if the variable norm is passed (with any value).

 type(vector) :: pt(0:4)

 pt(1) = ex
 pt(2) = ey
 pt(3) = ex - ey
 pt(4) = ex + ey
 pt(0) = pt(1)%face_normal4(pt1=pt(1), pt2=pt(2), pt3=pt(3), pt4=pt(4), norm='y')
 print "(3(F3.1,1X))", abs(pt(0)%x), abs(pt(0)%y), abs(pt(0)%z)

 type(vector) :: pt(0:4)

 pt(1) = ex
 pt(2) = ey
 pt(3) = ex - ey
 pt(4) = ex + ey
 pt(0) = face_normal4(pt1=pt(1), pt2=pt(2), pt3=pt(3), pt4=pt(4), norm='y')
 print "(3(F3.1,1X))", abs(pt(0)%x), abs(pt(0)%y), abs(pt(0)%z)

Arguments

Type	Intent	Optional		Name
type(vector),	intent(in)		::	pt1	First face point.
type(vector),	intent(in)		::	pt2	Second face point.
type(vector),	intent(in)		::	pt3	Third face point.
type(vector),	intent(in)		::	pt4	Fourth face point.
character(len=1),	intent(in),	optional	::	norm	If ‘norm’ is passed as argument the normal is normalized.

Return Value type(vector)

Face normal.

Calls

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