+Comparison of results from two sets of the same test executions
+'''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
+
+This algorithm enables comparison of results coming from two sets of the
+same test executions. It is used to quantify performance changes across
+all tests after test environment changes e.g. Operating System
+upgrades/patches, Hardware changes.
+
+It is assumed that each set of test executions includes multiple runs
+of the same tests, 10 or more, to verify test results repeatibility and
+to yield statistically meaningful results data.
+
+Comparison results are presented in a table with a specified number of
+the best and the worst relative changes between the two sets. Following table
+columns are defined:
+
+ - name of the test;
+ - throughput mean values of the reference set;
+ - throughput standard deviation of the reference set;
+ - throughput mean values of the set to compare;
+ - throughput standard deviation of the set to compare;
+ - relative change of the mean values.
+
+**The model**
+
+The model specifies:
+
+ - type: "table" - means this section defines a table.
+ - title: Title of the table.
+ - algorithm: Algorithm which is used to generate the table. The other
+ parameters in this section must provide all information needed by the used
+ algorithm.
+ - output-file-ext: Extension of the output file.
+ - output-file: File which the table will be written to.
+ - reference - the builds which are used as the reference for comparison.
+ - compare - the builds which are compared to the reference.
+ - data: Specify the sources, jobs and builds, providing data for generating
+ the table.
+ - filter: Filter based on tags applied on the input data, if "template" is
+ used, filtering is based on the template.
+ - parameters: Only these parameters will be put to the output data
+ structure.
+ - nr-of-tests-shown: Number of the best and the worst tests presented in the
+ table. Use 0 (zero) to present all tests.
+
+*Example:*
+
+::
+
+ -
+ type: "table"
+ title: "Performance comparison"
+ algorithm: "table_performance_comparison"
+ output-file-ext: ".csv"
+ output-file: "{DIR[DTR,PERF,VPP,IMPRV]}/vpp_performance_comparison"
+ reference:
+ title: "csit-vpp-perf-1801-all - 1"
+ data:
+ csit-vpp-perf-1801-all:
+ - 1
+ - 2
+ compare:
+ title: "csit-vpp-perf-1801-all - 2"
+ data:
+ csit-vpp-perf-1801-all:
+ - 1
+ - 2
+ data:
+ "vpp-perf-comparison"
+ filter: "all"
+ parameters:
+ - "name"
+ - "parent"
+ - "throughput"
+ nr-of-tests-shown: 20
+
+