Types of QIIME 2 Actions#
A QIIME 2 plugin action
is any operation that accepts parameters and files (:term:artifact
or metadata) as input, and generates some type of output.
Actions
are interpreted as โcommandsโ by QIIME 2 interfaces and come in three flavors:
A
Method
accepts some combination of QIIME 2Artifacts
andParameters
as input, and produces one or more QIIME 2 artifacts as output. These output artifacts could subsequently be used as input to other QIIME 2Methods
orVisualizers
.Methods
can produce intermediate or terminal outputs in a QIIME 2 analysis. For example, therarefy
method defined in theq2-feature-table
plugin accepts a feature table artifact and sampling depth as input and produces a rarefied feature table artifact as output. This rarefied feature table artifact could then be used in another analysis, such as alpha diversity calculations provided by thealpha
method inq2-diversity
.
A Visualizer
is similar to a Method
in that it accepts some combination of QIIME 2 Artifacts
and Parameters
as input.
In contrast to a method, a visualizer produces exactly one Visualization
as output.
Visualizations, by definition, cannot be used as input to other QIIME 2 methods or visualizers.
Thus, visualizers can only produce terminal output in a QIIME 2 analysis.
A Pipeline
accepts some combination of QIIME 2 Artifacts
and Parameters
as input and produces one or more artifacts and/or visualizations as output.
It does so by incorporating one or more methods
and/or visualizers
into a single registered action
.