Qbox DOS utilities

git-svn-id: http://qboxcode.org/svn/qb/trunk@1392 cba15fb0-1239-40c8-b417-11db7ca47a34

util/qbox_dos/qbox_dos.py

+#!/usr/bin/python
+# qbox_dos.py: extract dos from Qbox output
+# generate dos plot in gnuplot format
+# use: qbox_dos.py emin emax width file.r
+
+import xml.sax
+import sys
+import math
+
+if len(sys.argv) != 5:
+  print "use: ",sys.argv[0]," emin emax width file.r"
+  sys.exit()
+
+emin = float(sys.argv[1])
+emax = float(sys.argv[2])
+width = float(sys.argv[3])
+infile = sys.argv[4]
+
+ndos = 501
+de = (emax - emin)/(ndos-1)
+
+# normalized gaussian distribution in one dimension
+# f(x) = 1/(sqrt(pi)*width) * exp(-(x/width)^2 )
+def gauss(x, width):
+  return (1.0/(math.sqrt(math.pi)*width)) * math.exp(-(x/width)**2)
+  
+# Qbox output handler to extract and process data
+class QboxOutputHandler(xml.sax.handler.ContentHandler):
+  def __init__(self):
+    self.iter = 0
+    self.readData = 0
+
+  def startElement(self, name, attributes):
+    if name == "eigenvalues":
+      self.n = attributes["n"]
+      self.spin = attributes["spin"]
+      self.kpoint = attributes["kpoint"]
+      self.readData = 1
+      self.iter += 1
+      self.buffer = ""
+
+  def characters(self, data):
+    if self.readData:
+      self.buffer += data
+
+  def endElement(self, name):
+    if name == "eigenvalues":
+      self.readData = 0
+      self.compute_dos()
+
+  def compute_dos(self):
+    dos = [0] * ndos
+    self.e = self.buffer.split()
+    for i in range(len(self.e)):
+      for j in range(ndos):
+        ej = emin + j * de
+        dos[j] += gauss(float(self.e[i])-ej, width )
+    if self.iter > 1:
+      print
+      print
+    print "# ",infile, " iter=", self.iter," spin=",self.spin, \
+          " kpoint=", self.kpoint," width=",width
+    for j in range(ndos):
+      ej = emin + j * de
+      print ej, dos[j]
+
+parser = xml.sax.make_parser()
+handler = QboxOutputHandler()
+parser.setContentHandler(handler)
+parser.parse(infile)