ReadPDBfileAsPurepermutahedralComplex(str):: String --> PurePermComplex
ReadPDBfileAsPurePermutahedralComplex(str,r):: String, Int --> PurePermComplex

Reads a PDB (Protein Database) file identified by a string str such as "file.pdb" or "path/file.pdb" and returns a 3-dimensional pure permutahedral complex K. The complex K should represent a (protein backbone) knot but this is not guaranteed. A useful check in this direction is to test that K has the homotopy type of a circle.

If the test fails then try the function again with an integer r \ge 2 entered as the optional second argument. The integer determines the resolution with which the knot is constructed.