Add easy plotting to IPython extension.

Copy functionality from the old pdffit2lab script.

Author: pavoljuhas

diffpy/pdffit2/ipy_ext.py

@@ -1,9 +1,91 @@
+#!/usr/bin/env python
+
+"""This module defines functions within IPython session to simulate
+the old pdffit2 interactive session.
+
+Usage: %load_ext diffpy.pdffit2.ipy_ext
+"""
+
+
 def load_ipython_extension(ipython):
     from diffpy.pdffit2 import PdfFit
     pf = PdfFit()
+    pdf = EasyPDFPlotting(pf)
     print('        Type  help(pdffit)  or  help(topic)  for information.')
     print
-    ns = dict(pdffit=PdfFit)
+    ns = dict(pdffit=PdfFit, pdf=pdf)
     pf._exportAll(ns)
     ipython.user_ns.update(ns)
     return
+
+
+class EasyPDFPlotting(object):
+    """Convenience functions for accessing and plotting PDFfit2 data.
+    """
+
+    def __init__(self, pdffit_instance):
+        self._pdffit = pdffit_instance
+        return
+
+    @property
+    def r(self):
+        "R-grid for PDF simulation."
+        return self._asarray(self._pdffit.getR(), dtype=float)
+
+    @property
+    def Gobs(self):
+        "Observed PDF data."
+        return self._asarray(self._pdffit.getpdf_obs(), dtype=float)
+
+    @property
+    def Gcalc(self):
+        "Calculated PDF data."
+        return self._asarray(self._pdffit.getpdf_fit())
+
+    @property
+    def Gdiff(self):
+        "Difference between the observed and simulated PDF."
+        return self.Gobs - self.Gcalc
+
+    def showfit(self, offset=None):
+        """Plot observed and simulated PDFs and the difference curve.
+
+        offset   -- offset for the difference curve.
+
+        No return value.
+        """
+        from matplotlib.pyplot import gca
+        from math import floor
+        cr = self.r
+        cGobs = self.Gobs
+        cGcalc = self.Gcalc
+        cGdiff = self.Gdiff
+        if offset is None:
+            offset = floor(min([min(cGobs), min(cGcalc)]) - max(cGdiff))
+        ax = gca()
+        ax.plot(cr, cGobs, 'r.', cr, cGcalc, 'b-', cr, cGdiff + offset, 'g-')
+        xl = ax.xaxis.get_label().get_text()
+        yl = ax.yaxis.get_label().get_text()
+        if xl == "":
+            ax.set_xlabel('r (A)')
+        if yl == "":
+            ax.set_ylabel('G (A**-2)')
+        return
+
+    def showRw(self):
+        "Plot cumulative Rw."
+        from matplotlib.pyplot import gca
+        cRw = self._asarray(self._pdffit.getcrw())
+        ax = gca()
+        ax.plot(self.r, cRw)
+        ax.set_title('Cumulative Rw = %.4f' % cRw[-1])
+        ax.set_xlabel('r')
+        ax.set_ylabel('Rw')
+        return
+
+    @staticmethod
+    def _asarray(x, dtype=None):
+        import numpy
+        return numpy.asarray(x, dtype=dtype)
+
+# End of class EasyPDFPlotting