Hi,

While moving from Matlab to Numpy/Scipy/Matplotlib I need sometimes to work with Matlab figures. It would be nice if we could load Matlab figures in Python, extract the data and some basic parameters of how it was looking in Matlab and create its "clone" in matplotlib. At present the Matlab figures are MAT files and in the near future it will be HDF5, both formats are loadable. However, I have not found any reference for such attempts to load and parse the FIG files. As a beginner I find it difficult to write a large piece of code. However, if there are other interested users that can cooperate on such, I'd gladly contribute some hours for this task. Meanwhile, to show the proof-of-concept attempt is attached below. All your useful comments and suggestions are very welcome.

Thank you,

Alex

#------------ loadfig.py ---------------------- #

""" Loadfig loads simple Matlab figures as MAT files and plots the lines using matplotlib

"""

import numpy as np

from scipy.io import loadmat

import matplotlib.pyplot as plt

def lowest_order(d):

"""

lowestsc_order(hgstruct) finds the handle of axes (i.e. children of figure handles, etc.)

"""

while not 'graph2d.lineseries' in d['type']:

d = d['children'][0][0]

return d

def get_data(d):

"""

get_data(hgstruct) extracts XData, YData, Color and Marker of each line in the

given axis

Parameters

## ···

----------

hgstruct : structure

obtained from lowest_order(loadmat('matlab.fig'))

"""

xd,yd,dispname,marker,colors = [],[],[],[],[]

for i in d:

if i['type'] == 'graph2d.lineseries':

xd.append(i['properties'][0][0]['XData'][0][0])

yd.append(i['properties'][0][0]['YData'][0][0])

dispname.append(i['properties'][0][0]['DisplayName'][0][0])

marker.append(i['properties'][0][0]['Marker'][0][0])

colors.append(i['properties'][0][0]['Color'][0][0])

return np.asarray(xd),np.asarray(yd),dispname,np.asarray(marker).astype('S1'),colors

def plot_data(xd,yd,dispname=None,marker=None,colors=None):

"""

plot_data(xd,yd,dispname=None,marker=None,colors=None)

plots the data sets extracted by get_data(lowest_order(loadmat('matlab.fig')))

Parameters

----------

xd,yd : array_like

data arrays

dispname : array of strings

to be used in legend, optional

marker : array of characters

markers, e.g. ['o','x'], optional

colors : array of color sets

in RGB, e.g. [[0,0,1],[1,0,0]], optional

"""

for i,n in enumerate(xd):

plt.plot(xd[i].T,yd[i].T,color=tuple(colors[i]),marker=marker[i],linewidth=0)

plt.legend(dispname)

plt.show()

def main(filename):

"""

main(filename)

loads the filename (with the extension .fig) which is Matlab figure. At the moment only

simple 2D lines are supported.

Examples

-------

>>> loadfig('matlab.fig') # is equivalent to:

>>> d = loadmat(filename)

>>> d = d['hgS_070000']

>>> xd,yd,dispname,marker,colors = get_data(lowest_order(d))

>>> plot_data(xd,yd,dispname,marker,colors)

"""

d = loadmat(filename)

# ver 7.2 or lower:

d = d['hgS_070000']

xd,yd,dispname,marker,colors = get_data(lowest_order(d))

plot_data(xd,yd,dispname,marker,colors)

if __name__ == "__main__":

import sys

import os

try:

filename = sys.argv[1]

main(filename)

except:

print("Wrong file")

# ----------------------------- EOF loadfig.py --------------------------- #

Alex Liberzon

Turbulence Structure Laboratory [http://www.eng.tau.ac.il/efdl]

School of Mechanical Engineering

Tel Aviv University

Ramat Aviv 69978

Israel

Tel: +972-3-640-8928

Lab: +972-3-640-6860 (telefax)

E-mail: alexlib@...3412...