Interactive example gallery pages

docs/examples/interactive_examples/interactive_singlediode.py

@@ -0,0 +1,127 @@
+from bokeh.io import curdoc
+from bokeh.layouts import column, row
+from bokeh.models import (
+    ColumnDataSource, Select, CustomJS, ColorBar, LinearColorMapper
+)
+from bokeh.transform import transform
+from bokeh.plotting import figure, show
+
+import pandas as pd
+import numpy as np
+from pvlib import pvsystem
+
+irradiance_range = np.arange(0, 1300, 50)
+temperature_range = np.arange(-10, 70, 10)
+
+parameters = {
+    'alpha_sc': 0.004539,
+    'a_ref': 2.6373,
+    'I_L_ref': 5.114,
+    'I_o_ref': 8.196e-10,
+    'R_s': 1.065,
+    'R_sh_ref': 381.68,
+}
+
+dataset = []
+for irrad in irradiance_range:
+    for temp in temperature_range:
+
+        IL, I0, Rs, Rsh, nNsVth = pvsystem.calcparams_desoto(
+            irrad,
+            temp,
+            alpha_sc=parameters['alpha_sc'],
+            a_ref=parameters['a_ref'],
+            I_L_ref=parameters['I_L_ref'],
+            I_o_ref=parameters['I_o_ref'],
+            R_sh_ref=parameters['R_sh_ref'],
+            R_s=parameters['R_s'],
+            EgRef=1.121,
+            dEgdT=-0.0002677
+        )
+        curve_info = pvsystem.singlediode(
+            photocurrent=IL,
+            saturation_current=I0,
+            resistance_series=Rs,
+            resistance_shunt=Rsh,
+            nNsVth=nNsVth,
+            ivcurve_pnts=100,
+            method='lambertw'
+        )
+        data = {
+            'Geff': irrad,
+            'Tcell': temp,
+            'IL': IL,
+            'I0': I0,
+            'Rs': Rs,
+            'Rsh': Rsh,
+            'nNsVth': nNsVth,
+            'Isc': curve_info['i_sc'],
+            'Voc': curve_info['v_oc'],
+            'Imp': curve_info['i_mp'],
+            'Vmp': curve_info['v_mp'],
+            'Pmp': curve_info['p_mp'],
+        }
+        dataset.append(data)
+
+df = pd.DataFrame(dataset)
+source = ColumnDataSource(df)
+
+# default plot is Pmp vs Geff, colored by Tcell
+source.data['x'] = source.data['Geff']
+source.data['y'] = source.data['Pmp']
+source.data['c'] = source.data['Tcell']
+
+colormapper = LinearColorMapper(palette='Viridis256',
+                                low=df['Tcell'].min(),
+                                high=df['Tcell'].max())
+
+tooltips = [(label, "@"+label) for label in df.columns]
+
+# scatter plot using the 'x', 'y', and 'c' columns
+plot = figure(tooltips=tooltips)
+plot.circle(source=source, x='x', y='y',
+            fill_color=transform('c', colormapper),
+            radius=5, radius_units='screen')
+plot.xaxis[0].axis_label = 'Geff'
+plot.yaxis[0].axis_label = 'Pmp'
+
+color_bar = ColorBar(color_mapper=colormapper, location=(0,0))
+plot.add_layout(color_bar, 'right')
+
+# set the x/y/c values when the user changes the selections
+callback = CustomJS(args=dict(source=source,
+                              colormapper=colormapper,
+                              xaxis=plot.xaxis[0],
+                              yaxis=plot.yaxis[0]),
+                    code="""
+    var name = cb_obj.title;
+    var src = cb_obj.value;
+    if(name == 'X-var:'){
+        var dest = 'x';
+        xaxis.axis_label = src;
+    } else if(name == 'Y-var:'){
+        var dest = 'y';
+        yaxis.axis_label = src;
+    } else if(name == 'Color-var:'){
+        var dest = 'c';
+        cmap.low = Math.min(source.data[src]);
+        cmap.high = Math.max(source.data[src]);
+    } else {
+        throw "bad source object name!";
+    }
+    source.data[dest] = source.data[src];
+    source.change.emit();
+""")
+
+# controls:
+options = list(df.columns)
+xselect = Select(title="X-var:", value="Geff", options=options)
+yselect = Select(title="Y-var:", value="Pmp", options=options)
+cselect = Select(title="Color-var:", value="Tcell", options=options)
+
+xselect.js_on_change('value', callback)
+yselect.js_on_change('value', callback)
+cselect.js_on_change('value', callback)
+
+layout = row(column(xselect, yselect, cselect, width=100), plot)
+show(layout)

docs/examples/interactive_examples/interactive_tracking.py

@@ -0,0 +1,166 @@
+from bokeh.layouts import column, row
+from bokeh.models import (
+    ColumnDataSource, Slider, CustomJS, Span
+)
+from bokeh.plotting import figure, show
+
+import pandas as pd
+import numpy as np
+import pvlib
+
+times = pd.date_range('2019-06-01 05:15', '2019-06-01 21:00',
+                      freq='1min', closed='left', tz='US/Eastern')
+location = pvlib.location.Location(40, -80)
+solpos = location.get_solarposition(times)
+
+theta = pvlib.tracking.singleaxis(
+    solpos['zenith'],
+    solpos['azimuth'],
+    axis_tilt=0,
+    axis_azimuth=0,
+    max_angle=90,
+    backtrack=True,
+    gcr=0.5,
+)['tracker_theta'].fillna(0)
+
+# prevent weird shadows at night
+solpos['elevation'] = solpos['elevation'].clip(lower=0)
+
+curves_source = ColumnDataSource(data={
+    'times': times,
+    'tracker_theta': theta,  # degrees
+    'solar_elevation': np.radians(solpos['elevation']),
+    'solar_azimuth': np.radians(solpos['azimuth']),
+})
+
+source = ColumnDataSource(data={
+    # backtracking positions
+    'tracker1_x': [-1.5, -0.5],
+    'tracker1_y': [0.0, 0.0],
+    'tracker2_x': [0.5, 1.5],
+    'tracker2_y': [0.0, 0.0],
+
+    # ground line
+    'ground_x': [-3, 3],
+    'ground_y': [-1, -1],
+
+    # racking posts
+    'post1_x': [-1, -1],
+    'post1_y': [-1, 0],
+    'post2_x': [1, 1],
+    'post2_y': [-1, 0],
+})
+
+shadow_source = ColumnDataSource(data={
+    'xs': [[]],
+    'ys': [[]],
+})
+
+# Set up Scene diagram
+scene = figure(plot_height=350, plot_width=350, title="Tracker Position",
+               x_range=[-3, 3], y_range=[-3, 3])
+
+plot_args = dict(
+    source=source,
+    line_width=3,
+    line_alpha=1.0,
+)
+
+scene.line('tracker1_x', 'tracker1_y', **plot_args)
+scene.line('tracker2_x', 'tracker2_y', **plot_args)
+
+scene.line('ground_x', 'ground_y', source=source, line_width=1, line_color='black')
+scene.line('post1_x', 'post1_y', source=source, line_width=5, line_color='black')
+scene.line('post2_x', 'post2_y', source=source, line_width=5, line_color='black')
+
+scene.patches(xs="xs", ys="ys", fill_color="#333333", alpha=0.2, source=shadow_source)
+
+# Set up daily tracker angle curve
+curves = figure(plot_height=350, plot_width=350, title="Tracker Angle",
+                x_axis_type='datetime')
+
+curves_args = dict(
+    source=curves_source,
+    line_width=3,
+    line_alpha=1.0,
+)
+curves.line('times', 'tracker_theta', **curves_args)
+
+scrubber = Span(location=0,
+                dimension='height', line_color='black',
+                line_dash='dashed', line_width=3)
+curves.add_layout(scrubber)
+
+time_slider = Slider(title="Minute of Day", value=0, start=0, end=len(times)-1, step=1)
+
+time_slider.callback = CustomJS(args=dict(span=scrubber,
+                                          slider=time_slider,
+                                          curves_source=curves_source,
+                                          position_source=source,
+                                          shadow_source=shadow_source),
+                                code="""
+    // update time scrubber position and scene geometry
+
+    // update time scrubber position
+    var idx = slider.value;
+    span.location = curves_source.data['times'][idx];
+
+    // update tracker positions
+    var tracker_theta = curves_source.data['tracker_theta'][idx];
+    var dx = 0.5 * Math.cos(3.14159/180 * tracker_theta);
+    var dy = 0.5 * Math.sin(3.14159/180 * tracker_theta);
+    var data = position_source.data;
+    data['tracker1_x'] = [-1 - dx, -1 + dx];
+    data['tracker1_y'] = [ 0 - dy,  0 + dy];
+    data['tracker2_x'] = [ 1 - dx,  1 + dx];
+    data['tracker2_y'] = [ 0 - dy,  0 + dy];
+    position_source.change.emit();
+
+    // update shadow patches
+    var solar_elevation = curves_source.data['solar_elevation'][idx];
+    var solar_azimuth = curves_source.data['solar_azimuth'][idx];
+    var z = Math.sin(solar_elevation);
+    var x = -Math.cos(solar_elevation)*Math.sin(solar_azimuth);
+
+    // shadow length
+    z = z * 10;
+    x = x * 10;
+
+    var shadow1_x = [
+            data['tracker1_x'][0],
+            data['tracker1_x'][1],
+            data['tracker1_x'][1] - x,
+            data['tracker1_x'][0] - x
+    ];
+    var shadow1_y = [
+            data['tracker1_y'][0],
+            data['tracker1_y'][1],
+            data['tracker1_y'][1] - z,
+            data['tracker1_y'][0] - z
+    ];
+    var shadow2_x = [
+            data['tracker2_x'][0],
+            data['tracker2_x'][1],
+            data['tracker2_x'][1] - x,
+            data['tracker2_x'][0] - x
+    ];
+    var shadow2_y = [
+            data['tracker2_y'][0],
+            data['tracker2_y'][1],
+            data['tracker2_y'][1] - z,
+            data['tracker2_y'][0] - z
+    ];
+    shadow_source.data = {
+        'xs': [shadow1_x, shadow2_x],
+        'ys': [shadow1_y, shadow2_y],
+    };
+    shadow_source.change.emit();
+
+""")
+
+layout = column(
+    time_slider,
+    row(scene, curves)
+)
+
+show(layout)

docs/examples/plot_single_axis_tracking.py

@@ -20,6 +20,7 @@
 # towards the sun as much as possible in order to maximize the cross section
 # presented towards incoming beam irradiance.
 
+# sphinx_gallery_thumbnail_number = 2
 from pvlib import solarposition, tracking
 import pandas as pd
 import matplotlib.pyplot as plt
@@ -75,3 +76,12 @@
 
 plt.legend()
 plt.show()
+
+#%%
+# Interactive Demo
+# ----------------
+#
+# Drag the slider below to see how backtracking in morning and evening keeps
+# each row's shadows tangent to the next row without any overlap.
+#
+#  .. bokeh-plot:: ../../examples/interactive_examples/interactive_tracking.py