anchor.diff:          real :: x0,y0,x1,y1
           double precision :: slope, x_line
   
  -        internal_precision = 1e-7
  +        internal_precision = 1e-5
           if (present(precision)) internal_precision = precision
           n = size(poly,2)
   
  
positive.code:         endif
          w1=max(0.,w1); w2=max(0.,w2); w3=max(0.,w3);
  
          if (abs((w1+w2+w3)-1)>1e-4) then
              write(*,*) "Error, w1+w2+w3 != 1"
              write(*,*) w1,w2,w3
              write(*,*) "Point"
  
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"
  