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Version: Python

Create category histograms

This guide shows you how to use the plot_cat_hist method to create category histograms, which is used to show how frequently a set of discrete values (categories) occur.

Basic category histogram​

When data is sourced from a Deephaven table, the following syntax can be used:

.plot_cat_hist(series_name="series_name", t, category="Category").show()

  • plot_cat_hist is the method used to create a category histogram.
  • series_name is the name (as a string) you want to use to identify the series on the chart itself.
  • t is the table that holds the data you want to plot.
  • category is the name of the column (as a string) containing the discrete values.
  • show() tells Deephaven to draw the plot in the console.
from deephaven import new_table
from deephaven.column import int_col
from deephaven.plot.figure import Figure

source = new_table([int_col("Keys", [3, 2, 2, 1, 1, 1])])


new_plot = (
    Figure()
    .plot_cat_hist(series_name="Category Histogram", t=source, category="Keys")
    .show()
)

From an array​

When data is sourced from an array, the following syntax can be used:

.plot_cat_hist(series_name, category).show()

  • plot_cat_hist is the method used to create a category histogram.
  • series_name is the name (as a string) you want to use to identify the series on the plot itself.
  • category is a list containing the discrete values.
  • show tells Deephaven to draw the plot in the console.
from deephaven.plot.figure import Figure
import numpy as np

values = np.array([3, 2, 2, 1, 1, 1])

new_plot = (
    Figure()
    .plot_cat_hist(series_name="Values", category=list(values))
    .chart_title(title="Count of Values")
    .show()
)