evaluate.py

from __future__ import division

import csv
from itertools import groupby

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

# ------------------------------------------------------------------------------
# config & constants

LABEL_COLOR_MAP = {}
LABEL_COLOR_MAP["pierre"] = "xkcd:pink"
LABEL_COLOR_MAP["feuille"] = "xkcd:light green"
LABEL_COLOR_MAP["ciseaux"] = "xkcd:light blue"

CENTROID_COLOR_MAP = {}
CENTROID_COLOR_MAP["pierre"] = "xkcd:red"
CENTROID_COLOR_MAP["feuille"] = "xkcd:green"
CENTROID_COLOR_MAP["ciseaux"] = "xkcd:blue"

# ------------------------------------------------------------------------------
# helpers


def group_by(iterable, key):
    return groupby(sorted(iterable, key=key), key=key)


def get_label(row):
    return row[0]


def get_point(row):
    return np.array(map(float, row[1:]))


def centroid_from_points(points):
    return np.add.reduce(points) / len(points)


def points_per_label(recordpath):
    with open(recordpath, "rb") as record:
        rows = csv.reader(record, delimiter=";")

        # read and group data points by label
        return {group: map(get_point, grouper)
                for group, grouper in group_by(rows, key=get_label)}

# ------------------------------------------------------------------------------
# main


def main(recordpath):

    # create surface
    plt3d = plt.figure().gca(projection="3d")

    # ensure that the next plot doesn"t overwrite the first plot (?)
    axis = plt.gca()
    axis.set_xlabel("circularity")
    axis.set_ylabel("ellipticity")
    axis.set_zlabel("convexivity")
    axis.hold(True)

    for label, points in points_per_label(recordpath).iteritems():
        # draw data points
        for point in points:
            axis.scatter(*point, color=LABEL_COLOR_MAP[label], s=2**4)

        # draw centroids (centers of mass)
        centroid = centroid_from_points(points)
        axis.scatter(*centroid, color=CENTROID_COLOR_MAP[label], s=2**6)

    plt.show()

# ------------------------------------------------------------------------------
# kickoff


if __name__ == "__main__":
    main("assets/samples.csv")