Merge pull request #478 from NCAR/clean-up

Clean up plotting bugs

Gallery/Contours/NCL_ce_3_1.py

@@ -56,14 +56,19 @@
 # Contourf-plot data
 heatmap = t.plot.contourf(ax=ax,
                           transform=projection,
-                          levels=40,
+                          levels=np.arange(0, 32, .5),
                           vmin=0,
                           vmax=32,
                           cmap=newcmp,
                           add_colorbar=False)
 
 # Add colorbar
-cbar = plt.colorbar(heatmap, ticks=np.arange(0, 32, 2))
+cbar = plt.colorbar(heatmap,
+                    shrink=0.8,
+                    drawedges=True,
+                    ticks=np.arange(0, 32, 2),
+                    extendrect=True,
+                    extendfrac='auto')
 cbar.ax.set_yticklabels([str(i) for i in np.arange(0, 32, 2)])
 
 # Usa geocat.viz.util convenience function to set axes parameters without calling several matplotlib functions

Gallery/Contours/NCL_ce_3_2.py

@@ -56,14 +56,19 @@
 # Contourf-plot data
 heatmap = t.plot.contourf(ax=ax,
                           transform=projection,
-                          levels=40,
+                          levels=np.arange(0, 32, .5),
                           vmin=0,
                           vmax=32,
                           cmap=newcmp,
                           add_colorbar=False)
 
 # Add colorbar
-cbar = plt.colorbar(heatmap, ticks=np.arange(0, 32, 2))
+cbar = plt.colorbar(heatmap,
+                    shrink=0.8,
+                    drawedges=True,
+                    ticks=np.arange(0, 32, 2),
+                    extendrect=True,
+                    extendfrac='auto')
 cbar.ax.set_yticklabels([str(i) for i in np.arange(0, 32, 2)])
 
 # Adjust tick label size

Gallery/Contours/NCL_color_1.py

@@ -3,7 +3,6 @@
 ===============
 This script illustrates the following concepts:
    - Recreating a default NCL colormap
-   - Using Geocat-Viz Contour
 
 See following URLs to see the reproduced NCL plot & script:
     - Original NCL script: https://www.ncl.ucar.edu/Applications/Scripts/color_1.ncl
@@ -19,8 +18,10 @@
 # Import packages:
 
 import matplotlib.pyplot as plt
-import xarray as xr
+import cartopy.crs as ccrs
 import cmaps
+import numpy as np
+import xarray as xr
 
 import geocat.viz as gv
 import geocat.datafiles as gdf
@@ -30,16 +31,78 @@
 
 # Open a netCDF data file using xarray default engine and load the data into xarray
 ds = xr.open_dataset(gdf.get("netcdf_files/uv300.nc")).isel(time=1)
+U = ds.U
+
+# Use geocat-viz utility function to handle the no-shown-data
+# artifact of 0 and 360-degree longitudes
+U = gv.xr_add_cyclic_longitudes(U, 'lon')
 
 ###############################################################################
-# Plot with geocat.viz
+# Generate figure (set its size (width, height) in inches)
+plt.figure(figsize=(12, 8))
+
+# Generate axes, using Cartopy
+projection = ccrs.PlateCarree()
+ax = plt.axes(projection=projection)
+
+# Use global map and draw coastlines
+ax.set_global()
+ax.coastlines()
+
+# Import the default NCL colormap
+newcmp = cmaps.ncl_default
+
+# Contourf-plot data (for filled contours)
+# Note, min-max contour levels are hard-coded. contourf's automatic contour value selector produces fractional values.
+p = U.plot.contourf(ax=ax,
+                    vmin=-16.0,
+                    vmax=44,
+                    levels=16,
+                    cmap=newcmp,
+                    add_colorbar=False,
+                    transform=projection,
+                    extend='neither')
+
+# Contour-plot data (for contour lines)
+# Note, min-max contour levels are hard-coded. contourf's automatic contour value selector produces fractional values.
+U.plot.contour(ax=ax,
+               vmin=-16.0,
+               vmax=44,
+               levels=16,
+               colors='black',
+               linewidths=0.5,
+               transform=projection)
+
+# Add horizontal colorbar
+cbar = plt.colorbar(p,
+                    orientation='horizontal',
+                    shrink=0.75,
+                    drawedges=True,
+                    aspect=16,
+                    pad=0.075)
+cbar.ax.tick_params(labelsize=14)
+cbar.set_ticks(np.linspace(-12, 40, 14))
+
+# Use geocat.viz.util convenience function to set axes tick values
+gv.set_axes_limits_and_ticks(ax,
+                             xticks=np.linspace(-180, 180, 13),
+                             yticks=np.linspace(-90, 90, 7))
+
+# Use geocat.viz.util convenience function to make plots look like NCL plots by using latitude, longitude tick labels
+gv.add_lat_lon_ticklabels(ax)
 
-fig = plt.figure(figsize=(12, 8))
+# Use geocat.viz.util convenience function to add minor and major tick lines
+gv.add_major_minor_ticks(ax, labelsize=14)
 
-gv.Contour(ds.U,
-           main_title="Default Color",
-           fig=fig,
-           other=fig,
-           cmap=cmaps.ncl_default)
+# Use geocat.viz.util convenience function to add titles to left and right of the plot axis.
+gv.set_titles_and_labels(ax,
+                         maintitle="NCL Default Colors",
+                         lefttitle=U.long_name,
+                         lefttitlefontsize=16,
+                         righttitle=U.units,
+                         righttitlefontsize=16,
+                         xlabel="",
+                         ylabel="")
 
+# Show the plot
 plt.show()

Gallery/Contours/NCL_conLev_4.py

@@ -75,7 +75,14 @@
     add_labels=False)
 
 # Add horizontal colorbar
-cbar = plt.colorbar(p, orientation='horizontal', shrink=0.5)
+cbar = plt.colorbar(p,
+                    orientation='horizontal',
+                    shrink=0.6,
+                    extendrect=True,
+                    extendfrac='auto',
+                    pad=0.075,
+                    aspect=15,
+                    drawedges=True)
 cbar.ax.tick_params(labelsize=11)
 cbar.set_ticks([-12, -10, -8, -6, -4, -2, -1, 1, 2, 4, 6, 8, 10, 12])
 

Gallery/Contours/NCL_conwomap_2.py

@@ -65,7 +65,7 @@
                add_labels=False)
 
 # Add horizontal colorbar
-cbar = plt.colorbar(p, orientation='horizontal', shrink=0.5)
+cbar = plt.colorbar(p, orientation='horizontal', shrink=0.5, drawedges=True)
 cbar.ax.tick_params(labelsize=16)
 cbar.set_ticks(np.linspace(0, 9, 10))
 

Gallery/Contours/NCL_eof_1_1.py

@@ -232,7 +232,9 @@ def make_contour_plot(ax, dataset):
                     orientation='horizontal',
                     shrink=0.9,
                     pad=0.05,
-                    fraction=.02)
+                    fraction=.02,
+                    extendrect=True,
+                    extendfrac='auto')
 cbar.ax.tick_params(labelsize=8)
 
 # Set a common title

Gallery/Contours/NCL_lb_2.py

@@ -38,7 +38,7 @@
 # Plot:
 
 # Generate figure (set its size (width, height) in inches)
-fig = plt.figure(figsize=(10, 10))
+fig = plt.figure(figsize=(12, 6))
 
 # Generate axes using Cartopy and draw coastlines
 ax = plt.axes(projection=ccrs.PlateCarree())
@@ -48,19 +48,26 @@
 newcmp = cmaps.wgne15
 
 # Contourf-plot data (for filled contours)
-a = wrap_v.plot.contourf(levels=14,
+a = wrap_v.plot.contourf(levels=np.arange(-24, 25, 4),
                          cmap=newcmp,
                          add_colorbar=False,
                          add_labels=False)
 # Contour-plot data (for borderlines)
-wrap_v.plot.contour(levels=14, linewidths=0.5, cmap='black', add_labels=False)
+wrap_v.plot.contour(levels=np.arange(-24, 25, 4),
+                    linewidths=0.5,
+                    cmap='black',
+                    add_labels=False)
 
 # Add vertical colorbar
-clabels = [
-    "-70", "-50", "-30", "-10", "10", "30", "50", "70", "90", "110", "130",
-    "150"
-]
-cbar = fig.colorbar(a, label='', ticks=np.linspace(-24, 24, 12), shrink=0.4)
+cbar = plt.colorbar(a,
+                    ticks=np.arange(-20, 25, 4),
+                    shrink=0.8,
+                    aspect=10,
+                    extendrect=True,
+                    extendfrac='auto')
+
+# Change the colorbar tick labels
+clabels = np.arange(-70, 151, 20)
 cbar.ax.set_yticklabels(clabels)
 
 # Use geocat.viz.util convenience function to set axes limits & tick values without calling several matplotlib functions

Gallery/Contours/NCL_lb_4.py

@@ -3,12 +3,12 @@
 ===========
 This script illustrates the following concepts:
    - Drawing a horizontal colorbar
-   - Changing the labelbar labels
-   - Adding a title to a labelbar
-   - Changing the font of the labelbar's labels
-   - Making the labelbar label fonts smaller
-   - Centering the labels inside each box in a labelbar
-   - Adding a vertical title to a labelbar
+   - Changing the colorbar labels
+   - Adding a title to a colorbar
+   - Changing the font of the colorbar's labels
+   - Making the colorbar label fonts smaller
+   - Centering the labels inside each box in a colorbar
+   - Adding a vertical title to a colorbar
 
 See following URLs to see the reproduced NCL plot & script:
     - Original NCL script: https://www.ncl.ucar.edu/Applications/Scripts/lb_4.ncl
@@ -116,18 +116,22 @@
 cbar.ax.get_xaxis().set_ticks([])
 
 # Draw text in the center of each box
-offset = 1 / 13 / 2
+# The origin of the colorbar xaxis starts at right edge of the leftmost box
+# The offset moves the test left to the center of each box
+# The i/11 comes from the 11 main boxes on the colorbar since the boxes on each
+# end are the extensions for values that fall outside the colorbar rand
+offset = 3 / 22
 for i in range(1, 14):
-    cbar.ax.text(i / 13 - offset,
+    cbar.ax.text(i / 11 - offset,
                  0.45,
                  i,
                  horizontalalignment='center',
                  verticalalignment='center',
                  fontweight='bold',
                  transform=cbar.ax.transAxes)
 
-# Draw the colorbar title
-cbar.ax.text(1.1,
+# Draw the colorbar units
+cbar.ax.text(1.15,
              0.5,
              V.units,
              horizontalalignment='center',

Gallery/Contours/NCL_proj_1.py → Gallery/MapProjections/NCL_proj_1.py

@@ -65,7 +65,8 @@
                     shrink=0.8,
                     pad=0.05,
                     extendrect=True,
-                    ticks=cbar_ticks)
+                    ticks=cbar_ticks,
+                    drawedges=True)
 
 cbar.ax.tick_params(labelsize=10)
 

Gallery/Overlays/NCL_overlay_11a.py

@@ -157,7 +157,7 @@
                     ticks=clevs[1:-1],
                     drawedges=True,
                     orientation='horizontal')
-cbar.ax.tick_params(labelsize=12)
+cbar.ax.tick_params(labelsize=12, rotation=45)
 
 # Add the land mask feature on top of the contour plot (higher zorder)
 ax.add_feature(land_mask, zorder=2)

Gallery/Overlays/NCL_overlay_12.py

@@ -189,9 +189,8 @@
 # Manually set color bar tick length and tick labels padding.
 clb2.ax.yaxis.set_tick_params(length=0, pad=18, labelsize=14)
 
-# Center align colorbar tick labels
-ticklabs = clb2.ax.get_yticklabels()
-clb2.ax.set_yticklabels(ticklabs, ha='center')
+# Add tick labels and center align them
+clb2.ax.set_yticklabels(levels, ha='center')
 
 #
 # Set axes features (tick formats and main title)

Gallery/Panels/NCL_panel_18.py

@@ -141,11 +141,9 @@
                     drawedges=True,
                     format='%.1f')
 
-# Right align colorbar tick labels
+# Remove colorbar tick marks and adjust label spacing
 for cab in [cab1, cab2]:
-    ticklabs = cab.ax.get_yticklabels()
-    cab.ax.set_yticklabels(ticklabs, ha='right')
-    cab.ax.yaxis.set_tick_params(pad=30, length=0)
+    cab.ax.yaxis.set_tick_params(pad=10, length=0)
 
 # Generate plot
 plt.show()

Gallery/Panels/NCL_panel_3.py

@@ -44,7 +44,7 @@ def plot_labelled_filled_contours(data, ax=None):
     contours, and the contour labels."""
 
     # Import an NCL colormap, truncating it by using geocat.viz.util convenience function
-    newcmp = gv.truncate_colormap(cmaps.gui_default, minval=0.03, maxval=0.9)
+    newcmp = gv.truncate_colormap(cmaps.gui_default, minval=0.03, maxval=0.8)
 
     handles = dict()
     handles["filled"] = data.plot.contourf(
@@ -124,12 +124,15 @@ def plot_labelled_filled_contours(data, ax=None):
 plot_labelled_filled_contours(ds.V, ax=ax[1])
 
 # Add horizontal colorbar
-cbar = plt.colorbar(handles["filled"],
-                    ax=ax,
-                    orientation="horizontal",
-                    ticks=levels[:-1],
-                    drawedges=True,
-                    aspect=30)
+cbar = plt.colorbar(
+    handles["filled"],
+    ax=ax,
+    orientation="horizontal",
+    ticks=levels[:-1],  # keep the last colorbar tick from showing
+    drawedges=True,
+    extendrect=True,
+    extendfrac='auto',
+    aspect=30)
 cbar.ax.tick_params(labelsize=10)
 
 # Show the plot