plot a merged port and sidescan, cropping to a user-specified maximum range

plot_merge_crop.py

import matplotlib.pyplot as plt
import os
import numpy as np
from scipy.io import loadmat

sonpath = '/home/mydata/sonpath'
humfile = '/home/mydata/humfile.DAT'

# maximum range in m to shwo
maxy = 35

# if son path name supplied has no separator at end, put one on
if sonpath[-1]!=os.sep:
   sonpath = sonpath + os.sep

base = humfile.split('.DAT') # get base of file name for output
base = base[0].split(os.sep)[-1]

# remove underscores, negatives and spaces from basename
if base.find('_')>-1:
   base = base[:base.find('_')]
if base.find('-')>-1:
   base = base[:base.find('-')]
if base.find(' ')>-1:
   base = base[:base.find(' ')]
if base.find('.')>-1:
   base = base[:base.find('.')]

meta = loadmat(os.path.normpath(os.path.join(sonpath,base+'meta.mat')))
shape_port = np.squeeze(meta['shape_port'])
shape_star = np.squeeze(meta['shape_star'])

with open(os.path.normpath(os.path.join(sonpath,base+'_data_port_lw.dat')), 'r') as ff:
     port_fpw = np.memmap(ff, dtype='float32', mode='r', shape=tuple(shape_port))

with open(os.path.normpath(os.path.join(sonpath,base+'_data_star_lw.dat')), 'r') as ff:
     star_fpw = np.memmap(ff, dtype='float32', mode='r', shape=tuple(shape_star))

Zdist = meta['dist_m']
extent = shape_port[0]
ft = np.squeeze(1/meta['pix_m'])

fig = plt.figure()
plt.imshow(np.vstack((np.flipud(port_fpw), star_fpw)), cmap='gray', extent=[np.min(Zdist), np.max(Zdist), -extent*(1/ft), extent*(1/ft)])
plt.ylabel('Range (m)'), plt.xlabel('Distance along track (m)')

plt.axis('normal'); plt.axis('tight')
plt.ylim(-maxy, maxy)

plt.savefig(os.path.normpath(os.path.join(sonpath,'merged_cropped')),bbox_inches='tight',dpi=400)
del fig