User Function plugins

A User Function plugin can be defined by a class or a function in a python package.

A user function plugin defined by a function is a simple python function with one argument: results which contain a python dictionary of ToolResults.

This function returns a python dictionary with x and y list data to plot and optionally title, bottom and left string labels , e.g.

def positive(results):
    """ plot positive function values on the LineCut tool

    :param results: dictionary with tool results
    :type results: :obj:`dict`
    :returns: dictionary with user plot data
    :rtype: :obj:`dict`
    """
    userplot = {}
    if "linecut_1" in results:
        userplot = {"x": results["linecut_1"][0],
                    "y": [max(0.0, yy) for yy in results["linecut_1"][1]]}
    return userplot

A user function plugin defined by a class it should have defined __call__ method with one argument: results.

This __call__ function returns a python dictionary with x and y list data to plot and optionally title, bottom and left string labels.

Moreover, the class constructor has one configuration string argument initialized by an initialization parameter, e.g.

class LineCutFlat(object):

    """Flatten line cut"""

    def __init__(self, configuration=None):
        """ constructor

        :param configuration: JSON list with horizontal gap pixels to add
        :type configuration: :obj:`str`
        """
        #: (:obj:`list` <:obj: `str`>) list of indexes for gap
        self.__index = 1
        try:
            self.__flat = float(configuration)
        except Exception:
            self.__flat = 100000000.
            pass

    def __call__(self, results):
        """ call method

        :param results: dictionary with tool results
        :type results: :obj:`dict`
        :returns: dictionary with user plot data
        :rtype: :obj:`dict`
        """
        userplot = {}
        # print("RESULTS", results)
        label = "linecut_%s" % self.__index
        if label in results:
            userplot = {"x": results[label][0],
                        "y": [min(yy, self.__flat)
                              for yy in results[label][1]],
                        "title":
                        "%s flatten at '%s'" % (label, self.__flat)}
            if "unit" in results:
                userplot["bottom"] = results["unit"]
                userplot["left"] = "intencity"
        return userplot

or

import json


class DiffPDF(object):

    """diffpy PDF user function"""

    def __init__(self, configuration=None):
        """ constructor

        :param configuration: JSON list with config file and diff index
        :type configuration: :obj:`str`
        """
        #: (:obj:`list` <:obj: `str`>) list of indexes for gap
        self.__configfile = None

        config = None
        try:
            config = json.loads(configuration)
            try:
                self.__index = int(config[1])
            except Exception:
                self.__index = 1
            self.__configfile = str(config[0])
        except Exception:
            self.__index = 1
            self.__configfile = str(configuration)

        from diffpy.pdfgetx import loadPDFConfig
        self.__cfg = loadPDFConfig(self.__configfile)

    def __call__(self, results):
        """ call method

        :param results: dictionary with tool results
        :type results: :obj:`dict`
        :returns: dictionary with user plot data
        :rtype: :obj:`dict`
        """
        userplot = {}
        from diffpy.pdfgetx import PDFGetter
        self.__pg = PDFGetter(config=self.__cfg)
        label = "diff_%s" % self.__index
        if label in results and self.__configfile:
            qq = results[label][0]
            df = results[label][1]
            data_gr = self.__pg(qq, df)
            x = data_gr[0]
            y = data_gr[1]

            userplot = {
                "x": x, "y": y,
                "title": "DiffPDF: %s with %s" % (label, self.__configfile)
            }
        return userplot

To configure filters see User Functions settings.