anchor.diff:          real :: internal_precision
           double precision :: slope, offset
   
  -        internal_precision = 1e-7
  +        internal_precision = 1e-5
           if (present(precision)) internal_precision = precision
   
           online=.False.
  
positive.code:         real :: x0,y0,x1,y1
          double precision :: slope, x_line
  
          internal_precision = 1e-7
          if (present(precision)) internal_precision = precision
          n = size(poly,2)
  
  
negative.code: 
          w3 = 1 - w1 - w2
  
          if (minval([w1,w2,w3]) < -1e-3) then
              write(*,*) "ERROR: Point not located in bounding triangle"
              write(*,*) xi, yi
              write(*,*) "Triangle vertices"
  