plotComplex.py

# Unit test for persistence sheaf library
#
# Copyright (c) 2016-2019, Michael Robinson
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#       http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np
import matplotlib.pyplot as plt
import simplicialHomology as sh

def plot_complex(locations,cplx,color=None):
    """Plot an abstract simplicial complex given locations of nodes"""
    colors='mbcgyr'

    # Plot simplices of dimension 2 and higher
    for idx,f in enumerate(cplx):
        if len(f)>2:
            if color != None:
                if color[idx] >= len(colors):
                    col=colors[-1]
                else:
                    col=colors[color[idx]]
            else:
                col='g'
            for face in sh.ksublists(f,3):
                x,y=list(zip(*[locations[i] for i in face]))
                plt.fill(x,y,col,alpha=0.5)

    # Plot simplices of dimension 1 (edges)
    for idx,f in enumerate(cplx):
        if len(f)==2:
            if color != None:
                if color[idx] >= len(colors):
                    col=colors[-1]
                else:
                    col=colors[color[idx]]
            else:
                col='k'
            x,y=list(zip(*[locations[i] for i in f]))
            plt.plot(x,y,color=col,lw=3)

    # Plot simplices of dimension 0 (vertices)
    for idx,f in enumerate(cplx):
        if len(f)==1:
            if color != None:
                if color[idx] >= len(colors):
                    col=colors[-1]
                else:
                    col=colors[color[idx]]
            else:
                col='k'
            plt.plot(locations[f[0]][0],locations[f[0]][1],color=col,ms=4*np.pi,marker='.',markersize=30)
    return