Cannot pickle figure or axes (TypeError: instancemethod) #3392
Description
Couple of issues I've found.
def latex_float(f, pos=0):
float_str = "{0:.2g}".format(f)
if "e" in float_str:
base, exponent = float_str.split("e")
return r"${0} \times 10^{{{1}}}$".format(base, int(exponent))
else:
return r"${}$".format(float_str)
formatter = FuncFormatter(latex_float)
corr = np.corrcoef(data['x'], data['y'])[0,1]
fig, ax = pl.subplots(figsize=figsize)
hist, _, _, im = ax.hist2d(data['x'], data['y'], norm=LogNorm(), bins=(bins_x, bins_y) , alpha=0.75, cmap = cmap)
cbar = fig.colorbar(im, ticks=[0., 1., 2., 5., 10., 20., 50., 100., 200., 500., 1000., 2000., 5000.], format=formatter)
cbar.set_label('number density', fontsize=labelsize, labelpad=79)
cbar.ax.tick_params(labelsize=labelsize-6, width=3, length=15)
cbar.ax.minorticks_on()
ax.set_xlabel(label_x, fontsize=labelsize)
ax.set_ylabel(label_y, fontsize=labelsize)
ax.grid(True, which='both', linewidth=3, linestyle='--', alpha=0.5)
ax.text(0.95, 0.05, '$\mathrm{{Corr}} = {:0.4f}$'.format(corr), transform=ax.transAxes, fontsize=labelsize, verticalalignment='bottom', horizontalalignment='right', bbox=textprops)
ax.tick_params(axis='both', which='major', labelsize=labelsize-6)
pickle.dump(ax, file('ZH_ax.pkl', 'w+'))
fig.close()As it is, the code gives the following error:
Traceback (most recent call last):
File "make_plots_new.py", line 124, in <module>
pickle.dump(fig, file('ZH_ax.pkl', 'w+'))
File "/lib/python2.7/copy_reg.py", line 70, in _reduce_ex
raise TypeError, "can't pickle %s objects" % base.__name__
TypeError: can't pickle instancemethod objects
If I exclude the label formatter function in the colorbar, I get an error of
Traceback (most recent call last):
File "make_plots_new.py", line 124, in <module>
pickle.dump(fig, file('ZH_ax.pkl', 'w+'))
cPickle.UnpickleableError: Cannot pickle <type 'Image'> objects
How can one pickle?