New field.timelabel switch

It adds a label with the time of the snapshot on field figures.

Author: amorison

stagpy/config.py

@@ -103,6 +103,7 @@ def _index_collection(arg):
                                 'plot departure from average profile')),
     ('shift', Conf(None, True, None, {'type': int},
                    False, 'Shift plot horizontally')),
+    ('timelabel', switch_opt(False, None, 'add label with time')),
     ('interpolate', switch_opt(True, None, 'apply Gouraud shading')),
     ('colorbar', switch_opt(True, None, 'add color bar to plot')),
     ('ix', Conf(None, True, None, {'type': int},

stagpy/field.py

@@ -209,6 +209,7 @@ def plot_scalar(step, var, field=None, axis=None, **extra):
         axis.set_axis_off()
     else:
         axis.set_aspect(conf.plot.ratio / axis.get_data_ratio())
+
     axis.set_adjustable('box')
     axis.set_xlim(xmin, xmax)
     axis.set_ylim(ymin, ymax)
@@ -290,7 +291,7 @@ def cmd():
     for step in sdat.walk.filter(snap=True):
         for vfig in lovs:
             fig, axes = plt.subplots(ncols=len(vfig), squeeze=False,
-                                     figsize=(12 * len(vfig), 9))
+                                     figsize=(9 * len(vfig), 6))
             for axis, var in zip(axes[0], vfig):
                 if var[0] not in step.fields:
                     print("'{}' field on snap {} not found".format(var[0],
@@ -305,6 +306,11 @@ def cmd():
                         plot_iso(axis, step, var[1])
                     elif valid_field_var(var[1] + '1'):
                         plot_vec(axis, step, var[1])
+            if conf.field.timelabel:
+                time, unit = sdat.scale(step.timeinfo['t'], 's')
+                time = misc.scilabel(time)
+                axes[0, 0].text(0.02, 1.02, '$t={}$ {}'.format(time, unit),
+                                transform=axes[0, 0].transAxes)
             oname = '_'.join(chain.from_iterable(vfig))
             plt.tight_layout(w_pad=3)
             misc.saveplot(fig, oname, step.isnap)

stagpy/misc.py

@@ -33,6 +33,24 @@ def out_name(stem, timestep=None):
     return conf.core.outname + '_' + stem
 
 
+def scilabel(value, precision=2):
+    """Build scientific notation of some value.
+
+    This is dedicated to use in labels displaying scientific values.
+
+    Args:
+        value (float): numeric value to format.
+        precision (int): number of decimal digits.
+
+    Returns:
+        str: the scientific notation the specified value.
+    """
+    fmt = '{{:.{}e}}'.format(precision)
+    man, exp = fmt.format(value).split('e')
+    exp = int(exp)
+    return r'{}\times 10^{{{}}}'.format(man, exp)
+
+
 def saveplot(fig, *name_args, close=True, **name_kwargs):
     """Save matplotlib figure.