How do I use custom labels for ticks in Bokeh? - bokeh

Question

I understand how you specify specific ticks to show in Bokeh, but my question is if there is a way to assign a specific label to show versus the position. So for example
plot.xaxis[0].ticker=FixedTicker(ticks=[0,1])
will only show the x-axis labels at 0 and 1, but what if instead of showing 0 and 1 I wanted to show Apple and Orange. Something like
plot.xaxis[0].ticker=FixedTicker(ticks=[0,1], labels=['Apple', 'Orange'])
A histogram won't work for the data I am plotting. Is there anyway to use custom labels in Bokeh like this?

Answer 1

Fixed ticks can just be passed directly as the "ticker" value, and major label overrides can be provided to explicitly supply custom labels for specific values:
from bokeh.plotting import figure, output_file, show
p = figure()
p.circle(x=[1,2,3], y=[4,6,5], size=20)
p.xaxis.ticker = [1, 2, 3]
p.xaxis.major_label_overrides = {1: 'A', 2: 'B', 3: 'C'}
output_file("test.html")
show(p)

Answer 2

EDIT: Updated for Bokeh 0.12.5 but also see simpler method in the other answer.
This worked for me:
import pandas as pd
from bokeh.charts import Bar, output_file, show
from bokeh.models import TickFormatter
from bokeh.core.properties import Dict, Int, String
class FixedTickFormatter(TickFormatter):
"""
Class used to allow custom axis tick labels on a bokeh chart
Extends bokeh.model.formatters.TickFormatte
"""
JS_CODE = """
import {Model} from "model"
import * as p from "core/properties"
export class FixedTickFormatter extends Model
type: 'FixedTickFormatter'
doFormat: (ticks) ->
labels = #get("labels")
return (labels[tick] ? "" for tick in ticks)
#define {
labels: [ p.Any ]
}
"""
labels = Dict(Int, String, help="""
A mapping of integer ticks values to their labels.
""")
__implementation__ = JS_CODE
skills_list = ['cheese making', 'squanching', 'leaving harsh criticisms']
pct_counts = [25, 40, 1]
df = pd.DataFrame({'skill':skills_list, 'pct jobs with skill':pct_counts})
p = Bar(df, 'index', values='pct jobs with skill', title="Top skills for ___ jobs", legend=False)
label_dict = {}
for i, s in enumerate(skills_list):
label_dict[i] = s
p.xaxis[0].formatter = FixedTickFormatter(labels=label_dict)
output_file("bar.html")
show(p)

Answer 3

This can be dealt with as categorical data, see bokeh documentation.
from bokeh.plotting import figure, show
categories = ['A', 'B','C' ]
p = figure(x_range=categories)
p.circle(x=categories, y=[4, 6, 5], size=20)
show(p)