CGAL users discussion list

[Francesc Vila <>]

Hi,

I am doing an intersections check using 
CGAL::compute_intersection_points. I am using an exact predicates and 
inexact constructions kernel.

When I compute the intersections I receive an exception when is checking 
the precondition "comp_f(object, nodeP->object)" in CGAL::multiset. 
Could anyone explain why this exception is thrown?

In the comments it says that they are checking that the tree order is 
not violated, but I don't see why do those segments violate the order.

The contents of all the intersection segments is: (each line is a segment)

( 38029.437251200005, -91970.562748799988)   ( 38029.437251200005,  
38029.437251200005)
( 38029.437251200005,  38029.437251200005)   (-128029.43725120000,  
38029.437251200005)
(-128029.43725120000,  38029.437251200005)   (-128029.43725119998,  
21970.675886262117)
(-128029.43725119998,  21970.675886262117)   ( 21970.562748800003,  
21971.675886262114)
( 21970.562748800003,  21971.675886262114)   ( 21970.562748799999, 
-108028.50010501972)
( 21970.562748799999, -108028.50010501972)   ( 258029.43725120003, 
-108029.37439714751)
( 258029.43725120003, -108029.37439714751)   ( 258029.43725120003, 
-91970.562748799988)
( 258029.43725120003, -91970.562748799988)   ( 38029.437251200005, 
-91970.562748799988)
(-145000.00000000000,  5000.0000000000000)   ( 275000.00000000000,  
5000.0000000000000)

Thanks in advance,

Francesc Vila