left {tripack} | R Documentation |
This function returns a logical vector indicating which elements of the given points P0 are left of the directed edge P1->P2.
left(x0, y0, x1, y1, x2, y2)
x0 |
Numeric vector, 'x' coordinates of points P0 to check |
y0 |
Numeric vector, 'y' coordinates of points P0 to check, same length as 'x'. |
x1 |
'x' coordinate of point P1 |
y1 |
'y' coordinate of point P1 |
x2 |
'x' coordinate of point P2 |
y2 |
'y' coordinate of point P2 |
Logical vector.
This is an interface to the Fortran function VLEFT, wich is modeled after TRIPACKs LEFT function but accepts more than one point P0.
A. Gebhardt
left(c(0,0,1,1),c(0,1,0,1),0,0,1,1)