Fix to the documentation: to remove confusion with the perseus format.

git-svn-id: svn+ssh://scm.gforge.inria.fr/svnroot/gudhi/branches/cubical_complex_small_fix@3899 636b058d-ea47-450e-bf9e-a15bfbe3eedb

Former-commit-id: 6d600838396236ca95346719058bd8b834541814

1 files changed, 5 insertions, 2 deletions

diff --git a/src/Bitmap_cubical_complex/doc/Gudhi_Cubical_Complex_doc.h b/src/Bitmap_cubical_complex/doc/Gudhi_Cubical_Complex_doc.h
index d1836ef0..0c70c6e0 100644
--- a/src/Bitmap_cubical_complex/doc/Gudhi_Cubical_Complex_doc.h
+++ b/src/Bitmap_cubical_complex/doc/Gudhi_Cubical_Complex_doc.h
@@ -90,8 +90,11 @@ namespace cubical_complex {
  * In the current implantation, filtration is given at the maximal cubes, and it is then extended by the lower star
  * filtration to all cubes. There are a number of constructors that can be used to construct cubical complex by users
  * who want to use the code directly. They can be found in the \a Bitmap_cubical_complex class.
- * Currently one input from a text file is used. It uses a format used already in Perseus software
- * (http://www.sas.upenn.edu/~vnanda/perseus/) by Vidit Nanda. The file format is described here: \ref FileFormatsPerseus.
+ * Currently one input from a text file is used. It uses a format nspired from the Perseus software
+ * (http://www.sas.upenn.edu/~vnanda/perseus/) by Vidit Nanda. Note however an important difference: while Perseus assume
+ * the filtration of all maximal cubes to be non-negative, over here we do not enforce this and we allow any filtration values. 
+ * As a consequence one cannot use -1's to indicate missing cubes. If you have missing cubes in your complex, please set 
+ * their filtration to +Inf. The file format is described in details in here: \ref FileFormatsPerseus.
  *
  * \section PeriodicBoundaryConditions Periodic boundary conditions
  * Often one would like to impose periodic boundary conditions to the cubical complex. Let \f$ I_1\times ... \times