tsview: new "narrow" slider

+ tsview: switch to a new look of "slider" in tsview.py. The main changes are:

1. use a narrower slider on the Y-axis, for a more compact looking.

2. The slider is solely based on image number, instead of time, to be agnostic against TS files with different time gaps.

3. Plot the reference date as a "gray" dot on the slider, to be more visible.

4. use subplot() with tight_layout() to better scale the subplots

+ utils.ptime: add get_compact_isoformat()

mintpy/tsview.py

@@ -787,17 +787,15 @@ def plot(self):
                 disp_cbar=True,
                 disp_slider=True,
                 print_msg=self.print_msg)
-        self.fig_img = plt.figure(self.figname_img, figsize=self.figsize_img)
+        subplot_kw = dict(projection=self.map_proj_obj) if self.map_proj_obj is not None else {}
+        self.fig_img, self.ax_img = plt.subplots(figsize=self.figsize_img, **subplot_kw)
 
         # Figure 1 - Axes 1 - Displacement Map
-        axes_kw = dict(projection=self.map_proj_obj) if self.map_proj_obj is not None else {}
-        self.ax_img = self.fig_img.add_axes([0.125, 0.25, 0.75, 0.65], **axes_kw)
         img_data = np.array(self.ts_data[0][self.idx, :, :])
         img_data[self.mask == 0] = np.nan
         self.plot_init_image(img_data)
 
         # Figure 1 - Axes 2 - Time Slider
-        self.ax_tslider = self.fig_img.add_axes([0.125, 0.05, 0.75, 0.15])
         self.plot_init_time_slider(init_idx=self.idx, ref_idx=self.ref_idx)
         self.tslider.on_changed(self.update_time_slider)
 
@@ -851,7 +849,7 @@ def update_image(self, event):
 
             if idx is not None and idx != self.idx:
                 # update title
-                disp_date = self.dates[idx].strftime('%Y-%m-%d')
+                disp_date = self.dates[idx].strftime(self.disp_date_format)
                 sub_title = 'N = {n}, Time = {t}'.format(n=idx, t=disp_date)
                 self.ax_img.set_title(sub_title, fontsize=self.font_size)
 
@@ -864,8 +862,8 @@ def update_image(self, event):
                     data_img = ut.wrap(data_img, wrap_range=self.wrap_range)
 
                 # update
-                self.tslider.set_val(self.yearList[idx]) # update slider
-                self.img.set_data(data_img)              # update image
+                self.tslider.set_val(idx)         # update slider
+                self.img.set_data(data_img)       # update image
                 self.idx = idx
                 self.fig_img.canvas.draw_idle()
                 self.fig_img.canvas.flush_events()
@@ -874,38 +872,40 @@ def update_image(self, event):
 
     def update_time_slider(self, val):
         """Update Displacement Map using Slider"""
-        idx = np.argmin(np.abs(np.array(self.yearList) - self.tslider.val))
+        self.idx = self.tslider.val
+
         # update title
-        disp_date = self.dates[idx].strftime('%Y-%m-%d')
-        sub_title = 'N = {n}, Time = {t}'.format(n=idx, t=disp_date)
+        disp_date = self.dates[self.idx].strftime(self.disp_date_format)
+        sub_title = 'N = {n}, Time = {t}'.format(n=self.idx, t=disp_date)
         self.ax_img.set_title(sub_title, fontsize=self.font_size)
 
-        # read data
-        data_img = np.array(self.ts_data[0][idx, :, :])
+        # read/update 2D image data
+        data_img = np.array(self.ts_data[0][self.idx, :, :])
         data_img[self.mask == 0] = np.nan
         if self.wrap:
             if self.disp_unit_img == 'radian':
                 data_img *= self.range2phase
             data_img = ut.wrap(data_img, wrap_range=self.wrap_range)
-
-        # update data
         self.img.set_data(data_img)
-        self.idx = idx
+
+        # update figure
         self.fig_img.canvas.draw_idle()
         self.fig_img.canvas.flush_events()
         return
 
 
     ##---------- plot functions
     def plot_init_image(self, img_data):
+        """Plot the initial 2D image."""
         # prepare data
         if self.wrap:
             if self.disp_unit_img == 'radian':
                 img_data *= self.range2phase
             img_data = ut.wrap(img_data, wrap_range=self.wrap_range)
 
         # Title and Axis Label
-        disp_date = self.dates[self.idx].strftime('%Y-%m-%d')
+        self.disp_date_format = ptime.get_compact_isoformat(self.date_list[0])
+        disp_date = self.dates[self.idx].strftime(self.disp_date_format)
         self.fig_title = 'N = {}, Time = {}'.format(self.idx, disp_date)
 
         # Initial Pixel of interest
@@ -918,39 +918,31 @@ def plot_init_image(self, img_data):
 
         # call view.py to plot
         self.img, self.cbar_img = view.plot_slice(self.ax_img, img_data, self.atr, self)[2:4]
+        self.fig_img.canvas.set_window_title(self.figname_img)
+        self.fig_img.tight_layout(rect=(0,0,1,0.97))
+
         return self.img, self.cbar_img
 
 
     def plot_init_time_slider(self, init_idx=-1, ref_idx=None):
-        val_step = np.min(np.diff(self.yearList))
-        val_min = self.yearList[0]
-        val_max = self.yearList[-1]
+        """Plot the initial slider."""
+        # initiate axes
+        self.fig_img.subplots_adjust(bottom=0.16)
+        self.ax_tslider = self.fig_img.add_axes([0.125, 0.05, 0.75, 0.03])
 
+        # plot slider
         self.tslider = widgets.Slider(
-            self.ax_tslider,
-            label='Time',
-            valinit=self.yearList[init_idx],
-            valmin=val_min,
-            valmax=val_max,
-            valstep=np.array(self.yearList),
-        )
-
-        # plot vertical lines to mark the acquisition times
-        bar_width = val_step / 6.
-        num_val = len(self.yearList)
-        if num_val <= 100:
-            ymin, ymax = 0.25, 0.5
-            kwargs = dict(bottom=ymin, ecolor=None)
-            xdate = np.array(self.yearList)
-            self.tslider.ax.bar(xdate, np.ones(num_val)*ymax, width=bar_width, facecolor='black', **kwargs)
-            if ref_idx is not None:
-                self.tslider.ax.bar(xdate[ref_idx], ymax, width=bar_width*3, facecolor='crimson', **kwargs)
+            ax=self.ax_tslider,
+            label='Image',
+            valinit=init_idx,
+            valmin=0,
+            valmax=self.num_date-1,
+            valstep=1)
+
+        # plot reference date as a gray dot
+        if ref_idx is not None:
+            self.tslider.ax.scatter(ref_idx, 0.5, s=8**2, marker='o', color='gray', edgecolors='w')
 
-        # axis format
-        self.tslider.ax.set_xlim([val_min - bar_width / 2, val_max + bar_width / 2])
-        self.tslider.ax.set_ylim([0, 1])
-        self.tslider.ax.set_yticks([])
-        self.tslider.valtext.set_visible(False)   #hide slider values
         return self.tslider
 
 

mintpy/utils/plot.py

@@ -124,7 +124,7 @@ def add_inner_title(ax, title, loc, prop=None, **kwargs):
 
 
 def auto_figure_size(ds_shape, scale=1.0, disp_cbar=False, disp_slider=False,
-                     cbar_ratio=0.25, slider_ratio=0.30, print_msg=True):
+                     cbar_ratio=0.25, slider_ratio=0.15, print_msg=True):
     """Get auto figure size based on input data shape
     Adjust if display colobar on the right and/or slider on the bottom
 

mintpy/utils/ptime.py

@@ -15,6 +15,20 @@
 
 
 ################################################################
+def get_compact_isoformat(date_str):
+    """Get the "compact-looking" isoformat of the input datetime string.
+    Parameters: date_str   - str, an example date string
+    Returns:    iso_format - str, date string in "compact" iso format
+    """
+    date_str = date_str[0] if isinstance(date_str, list) else date_str
+    iso_format = get_date_str_format(date_str)
+    iso_format = iso_format.replace('y', 'Y')
+    iso_format = iso_format.replace('%Y%m%d', '%Y-%m-%d')
+    iso_format = iso_format.replace('%H%M%S', '%H:%M:%S')
+    iso_format = iso_format.replace('%H%M',   '%H:%M')
+    return iso_format
+
+
 def get_date_str_format(date_str):
     """Get the datetime string format as defined in:
     https://docs.python.org/3.7/library/datetime.html#strftime-and-strptime-behavior
@@ -25,8 +39,7 @@ def get_date_str_format(date_str):
                             YYMMDD
     Returns:    date_str_format - str, datetime string format
     """
-    if isinstance(date_str, list):
-        date_str = date_str[0]
+    date_str = date_str[0] if isinstance(date_str, list) else date_str
 
     try:
         date_str = date_str.decode('utf8')