I have a dataframe of multiple columns. First two columns are x and y coordinates and the rest columns are different property values for (x,y) pairs.
import pandas as pd
import numpy as np
df = pd.DataFrame()
df['x'] = np.random.randint(1,1000,100)
df['y'] = np.random.randint(1,1000,100)
df['val1'] = np.random.randint(1,1000,100)
df['val2'] = np.random.randint(1,1000,100)
df['val3'] = np.random.randint(1,1000,100)
print df.head()
x y val1 val2 val3
0 337 794 449 969 933
1 19 563 592 677 886
2 512 467 664 160 16
3 36 112 91 230 910
4 972 572 336 879 860
Using customJS in Bokeh, I would like to change the value of color in 2-D heatmap by providing a drop down menu.
from bokeh.plotting import figure
from bokeh.models import ColumnDataSource
from bokeh.models import LinearColorMapper
from bokeh.palettes import RdYlBu11 as palette
p = figure()
source = ColumnDataSource(df)
color_mapper = LinearColorMapper(palette=palette)
p.patches('x', 'y', source=source,\
fill_color={'field': 'val1', 'transform':color_mapper})
show(p)
The above commands plot a color map whose color is determined by the column 'val1'. I would like to plot different columns (either val1, val2, or val3) based on whatever is selected in the drop down menu.
I can create a drop down widget in bokeh by doing
from bokeh.models.widgets import Select
select = Select(title="Option:", value="val1", options=["val1","val2","val3"])
But, I'm not quite sure how I can use the selected value to update the plot by using callback.
Could someone give me a guideline here?
Thanks.