Example #1
0
func main() {
	libPath := util.Arg(0)
	chain := util.Arg(1)
	pdbEntryPath := util.Arg(2)
	bowOut := util.Arg(3)

	lib := util.StructureLibrary(libPath)
	entry := util.PDBRead(pdbEntryPath)

	thechain := entry.Chain(chain[0])
	if thechain == nil || !thechain.IsProtein() {
		util.Fatalf("Could not find chain with identifier '%c'.", chain[0])
	}

	bow := bow.BowerFromChain(thechain).StructureBow(lib)
	if bowOut == "--" {
		fmt.Println(bow)
	} else {
		util.BowWrite(util.CreateFile(bowOut), bow)
	}
}
Example #2
0
// BowerOpen reads the contents of `fpath` and attempts to interpret it as a
// value (or values) that implement the `bow.Bower` interface. The list of
// `bow.Bower` values returned is guaranteed to be homogenous: they will
// either be all `bow.SequenceBower` values or `bow.StructureBower` values.
//
// The actual return value of the function is a receive-only channel of BowerErr
// values. Each BowerErr value either has the `Bower` member set or has the
// `err` field set to an error that prevented the file from being opened.
// Errors in this case are reserved for files that appear to be capable of
// producing a BOW, but were unable to be read.
//
// If the fpath given cannot be detected as a bower file, then a closed empty
// channel will be returned. A warning is also emitted to stderr.
//
// `lib` is a fragment library that is used to help interpret what kind of
// value must be in `r`. For example, if `lib` is a sequence fragment library,
// then `BowerOpen` is guaranteed to return a `Bower` value that implements the
// `bow.SequenceBower` interface.
//
// As of now, `BowerOpen` can read these types of files:
//
//	File extension                 Format    Interpretation
//	*.{ent.gz,pdb,ent}             PDB       whatever `lib` is
//	*.{fasta,fas,fasta.gz,fas.gz}  FASTA     sequence
//	everything else                error     invalid
//
// Note that special syntax for PDB file names is supported. Namely, chain
// identifiers can be appended to the end of the file name, and only that chain
// will be included in the `bow.Bower` value. Otherwise, all chains in the PDB
// entry will be returned as individual `bow.Bower` values.
//
// The format is simple and easily demonstrated by examples:
//
//	1ctf.end.gz       Chains A and B
//	1ctf.ent.gz:A     Only chain A
//	1ctf.ent.gz:B     Only chain B
//	1ctf.ent.gz:A,B   Chains A and B
//
// A secondary format is also accepted. The following are equivalent to their
// corresponding examples above:
//
//	1ctf
//	1ctfA
//	1ctfB
//	1ctf:A,B
//
// Finally, `fpath` may be the name of a PDB identifier and its file path will
// be inferred from the value of the `PDB_PATH` environment variable.
// Alternatively, `fpath` may be the name of a SCOP domain, and its
// corresponding PDB file will be inferred from the value of the
// `SCOP_PDB_PATH` environment variable.
func BowerOpen(fpath string, lib fragbag.Library, models bool) <-chan BowerErr {
	if lib == nil {
		Fatalf("Files can only be converted to Fragbag frequency vectors " +
			"if a fragment library is specified.")
	}

	bowers := make(chan BowerErr, 100)
	switch {
	case IsPDB(fpath):
		go func() {
			defer close(bowers)

			entry, chains, err := PDBOpen(fpath)
			if err != nil {
				err = fmt.Errorf("Error reading '%s': %s", fpath, err)
				bowers <- BowerErr{Err: err}
				return
			}

			if fragbag.IsStructure(lib) {
				for i := range chains {
					if !chains[i].IsProtein() {
						continue
					}

					if !models {
						b := bow.BowerFromChain(chains[i])
						bowers <- BowerErr{Bower: b}
					} else {
						for _, m := range chains[i].Models {
							b := bow.BowerFromModel(m)
							bowers <- BowerErr{Bower: b}
						}
					}
				}
			} else {
				for i := range chains {
					if !chains[i].IsProtein() {
						continue
					}

					s := chains[i].AsSequence()
					if s.Len() == 0 {
						s = aminoFromStructure(chains[i])
						if s.Len() == 0 {
							Warnf("Chain '%s:%c' has no amino sequence.",
								entry.IdCode, chains[i].Ident)
							continue
						}
					}
					bowers <- BowerErr{Bower: bow.BowerFromSequence(s)}
				}
			}
		}()
		return bowers
	case IsFasta(fpath) && !fragbag.IsStructure(lib):
		go func() {
			defer close(bowers)

			r, fp, err := fastaOpen(fpath)
			if err != nil {
				err = fmt.Errorf("Error reading file: %s", err)
				bowers <- BowerErr{Err: err}
				return
			}
			defer fp.Close()

			fr := fasta.NewReader(r)
			for {
				s, err := fr.Read()
				if err != nil {
					if err == io.EOF {
						break
					}
					err = fmt.Errorf("Error reading file: %s", err)
					bowers <- BowerErr{Err: err}
					return
				}
				bowers <- BowerErr{Bower: bow.BowerFromSequence(s)}
			}
		}()
		return bowers
	}
	Warnf("I don't know how to produce a Fragbag frequency vector "+
		"from the file '%s'.", fpath)
	close(bowers)
	return bowers
}