Add initial app

Author: NicholasCote

web-app/app.py

@@ -0,0 +1,95 @@
+import panel as pn
+import xarray as xr
+import holoviews as hv
+from holoviews import opts
+import hvplot.xarray
+
+hv.extension("bokeh")
+
+## Load data
+
+rda_url = 'https://data.rda.ucar.edu/'
+annual_means = rda_url + 'pythia_era5_24/annual_means/'
+xrds = xr.open_dataset(annual_means + "temp_2m_annual_1940_2023.zarr", engine= 'zarr')
+xrds.load()
+
+xrds['VAR_2T_ANOM_FROM_1940'] = xrds['VAR_2T'] - xrds['VAR_2T'][0]
+
+## Widget configuration
+w_time = pn.widgets.IntSlider(name='Year', start=0, end=83)
+
+w_var = pn.widgets.Select(name='Data Variable', options=list(xrds.data_vars))
+
+dataset_controls = pn.WidgetBox(
+                                '## Dataset Controls', 
+                                w_var, 
+                                )
+
+w_cmap = pn.widgets.Select(name='Colormap', options=['inferno', 'plasma', 'coolwarm'])
+
+w_plot_type = pn.widgets.Select(name='Plot Type', options=['Color Plot', 'Contour', 'Filled Contour'])
+
+plot_controls = pn.WidgetBox(
+                            '## Plot Controls',
+                            w_plot_type,
+                            w_cmap, 
+                            )
+
+w_player = pn.widgets.Player(
+    value=0,
+    start=0,
+    end=83,
+    name="Year",
+    loop_policy="loop",
+    interval=300,
+    align="center",
+    width_policy='fit'
+)
+
+## Function to create the plot
+
+def plot_ds(time, var, cmap, plot_type):
+    clim = (xrds[var].values.min(), xrds[var].values.max())
+    
+    if plot_type == "Color Plot":
+        return xrds[var].isel(time=time).hvplot(cmap=cmap, 
+                                                              title=str(f"{var} year {time}"),
+                                                              clim=clim,
+                                                              dynamic=False,
+                                                              rasterize=True,
+                                                              precompute=True,
+                                               ).opts(framewise=False)
+    
+    elif plot_type == "Contour":
+        return xrds[var].isel(time=time).hvplot.contour(cmap=cmap,
+                                          dynamic=False,
+                                          rasterize=True,
+                                          title=str(f"{var} Year: {time}"),
+                                          clim=clim,
+                                          precompute=True,).opts(framewise=False)
+    elif plot_type == "Filled Contour":
+        return xrds[var].isel(time=time).hvplot.contourf(cmap=cmap,
+                                          dynamic=False,
+                                          rasterize=True,
+                                          title=str(f"{var} Year: {time}"),
+                                          clim=(200, 300),
+                                          precompute=True,).opts(framewise=False)     
+
+## Panel App configuration
+
+controls = pn.Column(dataset_controls, plot_controls)
+
+app = pn.Row(
+    controls,
+    pn.Column(pn.panel(
+        hv.DynamicMap(pn.bind(
+            plot_ds, 
+            time=w_player,
+            var=w_var,
+            cmap=w_cmap,
+            plot_type = w_plot_type
+        )
+                     )
+    ),
+             w_player)
+).servable()