# core-features: Identify core features in table¶

#### Docstring:

Usage: qiime feature-table core-features [OPTIONS]

Identify "core" features, which are features observed in a user-defined
fraction of the samples. Since the core features are a function of the
fraction of samples that the feature must be observed in to be considered
core, this is computed over a range of fractions defined by the
min_fraction, max_fraction, and steps parameters.

Inputs:
--i-table ARTIFACT FeatureTable[Frequency]
The feature table to use in core features
calculations.                                [required]
Parameters:
--p-min-fraction PROPORTION Range(0.0, 1.0, inclusive_start=False)
The minimum fraction of samples that a feature must be
observed in for that feature to be considered a core
feature.                                 [default: 0.5]
--p-max-fraction PROPORTION Range(0.0, 1.0, inclusive_end=True)
The maximum fraction of samples that a feature must be
observed in for that feature to be considered a core
feature.                                 [default: 1.0]
--p-steps INTEGER    The number of steps to take between min-fraction and
Range(2, None)     max-fraction for core features calculations. This
parameter has no effect if min-fraction and
max-fraction are the same value.        [default: 11]
Outputs:
--o-visualization VISUALIZATION
[required]
Miscellaneous:
--output-dir PATH    Output unspecified results to a directory
--verbose / --quiet  Display verbose output to stdout and/or stderr during
execution of this action. Or silence output if
execution is successful (silence is golden).
--examples           Show usage examples and exit.
--citations          Show citations and exit.
--help               Show this message and exit.

#### Import:

from qiime2.plugins.feature_table.visualizers import core_features


#### Docstring:

Identify core features in table

Identify "core" features, which are features observed in a user-defined
fraction of the samples. Since the core features are a function of the
fraction of samples that the feature must be observed in to be considered
core, this is computed over a range of fractions defined by the
min_fraction, max_fraction, and steps parameters.

Parameters
----------
table : FeatureTable[Frequency]
The feature table to use in core features calculations.
min_fraction : Float % Range(0.0, 1.0, inclusive_start=False), optional
The minimum fraction of samples that a feature must be observed in for
that feature to be considered a core feature.
max_fraction : Float % Range(0.0, 1.0, inclusive_end=True), optional
The maximum fraction of samples that a feature must be observed in for
that feature to be considered a core feature.
steps : Int % Range(2, None), optional
The number of steps to take between min_fraction and max_fraction
for core features calculations. This parameter has no effect if
min_fraction and max_fraction are the same value.

Returns
-------
visualization : Visualization