Hi
I want to apologize if this question was already answered, but I was unable to find this information by searching.
And as I’ve started using Bokeh 2 weeks ago, maybe this is trivial question
I want to access currently zoomed (zoomed by tools), to make “upsampling” data.
I was able to do this using “hidden” TextInput, but I want to ask if there is simpler (cleaner?) way of doing this…
Funny is that in in 0.10 that wasn’t working (value in TextInput was updating, but reading it back by ‘value’ wasn’t showing change - also on change event wasn’t fired, I need to press enter to get it posted), but in 0.11 is working as I wanted…
This is script that I’ve created (last night so sorry if these are errors/stupid things) is almost working properly (reset tool doesn’t fire range event).
(bokeh serve)
···
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from bokeh.plotting import Figure
from bokeh.models.widgets import VBoxForm, TextInput
from bokeh.models import ColumnDataSource, CustomJS
from bokeh.models.glyphs import Quad
import pandas as pd
from bokeh.io import curdoc
import time
AAPL = pd.read_csv(
“http://ichart.yahoo.com/table.csv?s=AAPL&a=0&b=1&c=2000&d=0&e=1&f=2010”,
parse_dates=[‘Date’]
)
def ConvertToEpoch(time_data):
return time.mktime(time_data.timetuple()) * 1000
def update_data(attrname,old,new):
start_x = float(text_start_x.value)
end_x=float(text_end_x.value)
NewestDate_i=0
OldestDate_i=len(AAPL[‘Date’])
for i in range(0,len(AAPL[‘Date’])):
curr_time=ConvertToEpoch(AAPL[‘Date’][i])
if curr_time>start_x and curr_time<end_x:
if NewestDate_i==0:
NewestDate_i=i
OldestDate_i=i
new_step=int((OldestDate_i-NewestDate_i)/PLOT_WIDTH)
if new_step<1: new_step=1
plot_zoomed.y_range.start=min(source_zoomed.data[‘y’])
plot_zoomed.y_range.end=max(source_zoomed.data[‘y’])
source_zoomed.data=dict(x=AAPL[‘Date’][NewestDate_i:OldestDate_i:new_step], y=AAPL[‘Close’][NewestDate_i:OldestDate_i:new_step])
sourceQuad.data = dict(left=[start_x],top=[Max_Y],right=[end_x],bottom=[Min_Y])
def print_value(attrname,old,new):
update_data()
LastElement=len(AAPL[‘Date’])-1
source_small = ColumnDataSource(data=dict(x=AAPL[‘Date’][0:LastElement-1:10], y=AAPL[‘Close’][0:LastElement-1:10]))
source_zoomed = ColumnDataSource(data=dict(x=AAPL[‘Date’][0:LastElement-1:10], y=AAPL[‘Close’][0:LastElement-1:10]))
Min_Y=int(min(source_small.data[‘y’])-10)
Max_Y=int(max(source_small.data[‘y’])+10)
#Range_Y=Range1d(Min_Y,Max_Y)
PLOT_WIDTH=500
sourceQuad = ColumnDataSource(dict(left=[min(source_small.data[‘x’])],top=[Max_Y],right=[max(source_small.data[‘x’])],bottom=[Min_Y]))
toolset = “box_zoom,resize,pan,reset,save,xwheel_zoom”
plot_zoomed = Figure(plot_width=PLOT_WIDTH, plot_height=500, x_axis_type=“datetime”,tools=toolset, lod_factor=10,lod_timeout=100)
plot_zoomed.line(‘x’, ‘y’,source=source_zoomed, color=‘navy’, alpha=0.5)
plot = Figure(plot_width=PLOT_WIDTH, plot_height=250, x_axis_type=“datetime”,toolbar_location=None,lod_factor=10,lod_timeout=100)
plot.line(‘x’, ‘y’,source=source_small, color=‘navy’, alpha=0.5)
plot.y_range.start=Min_Y
plot.y_range.end=Max_Y
glyph = Quad(left=“left”, right=“right”, top=“top”, bottom=“bottom”, fill_color="#b3de69", fill_alpha=0.1)
plot.add_glyph(sourceQuad, glyph)
RangeStartX=0
RangeEndX=1
text_start_x = TextInput(title=“X range start”, name=‘x_range_start’, value=“0”)
text_end_x = TextInput(title=“X range end”, name=‘x_range_end’, value=“1”)
text_start_x.on_change(‘value’, update_data)
text_end_x.on_change(‘value’, update_data)
toolset = “box_zoom,resize,pan,reset,save,x_wheel_zoom”
plot_zoomed.x_range.callback = CustomJS(args=dict(xrange=plot_zoomed.x_range,start_x=text_start_x,end_x=text_end_x),code="""
var start = xrange.get(“start”);
var end = xrange.get(“end”);
start_x.set(“value”,start.toString());
end_x.set(“value”,end.toString());
start_x.trigger(‘change’);
end_x.trigger(‘change’);
“”")
curdoc().add_root(VBoxForm(children=[plot_zoomed,plot], width=1000))
============================
Regards
Ser