def plot_pct_variance_per_principal_component(dataset, plot_type="bar"):
"""
Generates a plot to visualize the percentage of variance captured
by each principal component in the data set.
Args:
dataset: model.DataSet
The data set whose principal components will be examined. Should not
already be reduced.
plot_type: string
The plot type to generate. Supported plot types are:
'bar': vertical bar chart
'barh': horizontal bar chart
'line': line chart
Default is 'bar'.
Returns:
void, but produces a matplotlib plot.
Raises:
UnsupportedPlotTypeError if plot_type is not recognized.
"""
# Fail early: check plot type here right away even though the plotting
# module will check it later. Don't want a user with a large data set to
# wait for all the processing to occur only to find out they made a typo
# on the plot type.
plotting.verify_supported_series_plot_type(plot_type)
variances = get_pct_variance_per_principal_component(dataset)
plotting.plot_percent_series(variances, plot_type)
def plot_pct_variance_per_principal_component(dataset, plot_type="bar"):
"""
Generates a plot to visualize the percentage of variance captured
by each principal component in the data set.
Args:
dataset: model.DataSet
The data set whose principal components will be examined. Should not
already be reduced.
plot_type: string
The plot type to generate. Supported plot types are:
'bar': vertical bar chart
'barh': horizontal bar chart
'line': line chart
Default is 'bar'.
Returns:
void, but produces a matplotlib plot.
Raises:
UnsupportedPlotTypeError if plot_type is not recognized.
"""
# Fail early: check plot type here right away even though the plotting
# module will check it later. Don't want a user with a large data set to
# wait for all the processing to occur only to find out they made a typo
# on the plot type.
plotting.verify_supported_series_plot_type(plot_type)
variances = get_pct_variance_per_principal_component(dataset)
plotting.plot_percent_series(variances, plot_type)
def test_verify_supported_series_plot_type(self):
# just make sure no exceptions thrown
plotting.verify_supported_series_plot_type("bar")
plotting.verify_supported_series_plot_type("barh")
plotting.verify_supported_series_plot_type("line")
# make sure this does cause an exception
self.assertRaises(errors.UnsupportedPlotTypeError,
plotting.verify_supported_series_plot_type, "turkey")
