--- /dev/null
+package jalview.analysis.scoremodels;
+
+import jalview.api.analysis.SimilarityParamsI;
+
+/**
+ * A class to hold parameters that configure the pairwise similarity
+ * calculation. Based on the paper
+ *
+ * <pre>
+ * Quantification of the variation in percentage identity for protein sequence alignments
+ * Raghava, GP and Barton, GJ
+ * BMC Bioinformatics. 2006 Sep 19;7:415
+ * </pre>
+ *
+ * @see https://www.ncbi.nlm.nih.gov/pubmed/16984632
+ */
+public class SimilarityParams implements SimilarityParamsI
+{
+ /**
+ * Based on Jalview's Comparison.PID method, which includes gaps and counts
+ * them as matching; it counts over the length of the shorter sequence
+ */
+ public static final SimilarityParamsI Jalview = new SimilarityParams(
+ true, true, true, true);
+
+ /**
+ * 'SeqSpace' mode PCA calculation includes gaps but does not count them as
+ * matching; it uses the longest sequence length
+ */
+ public static final SimilarityParamsI SeqSpace = new SimilarityParams(
+ true, false, true, true);
+
+ /**
+ * as described in the Raghava-Barton paper
+ * <ul>
+ * <li>ignores gap-gap</li>
+ * <li>does not score gap-residue</li>
+ * <li>includes gap-residue in lengths</li>
+ * <li>matches on longer of two sequences</li>
+ * </ul>
+ */
+ public static final SimilarityParamsI PID1 = new SimilarityParams(false,
+ false, true, false);
+
+ /**
+ * as described in the Raghava-Barton paper
+ * <ul>
+ * <li>ignores gap-gap</li>
+ * <li>ignores gap-residue</li>
+ * <li>matches on longer of two sequences</li>
+ * </ul>
+ */
+ public static final SimilarityParamsI PID2 = new SimilarityParams(false,
+ false, false, false);
+
+ /**
+ * as described in the Raghava-Barton paper
+ * <ul>
+ * <li>ignores gap-gap</li>
+ * <li>ignores gap-residue</li>
+ * <li>matches on shorter of sequences only</li>
+ * </ul>
+ */
+ public static final SimilarityParamsI PID3 = new SimilarityParams(false,
+ false, false, true);
+
+ /**
+ * as described in the Raghava-Barton paper
+ * <ul>
+ * <li>ignores gap-gap</li>
+ * <li>does not score gap-residue</li>
+ * <li>includes gap-residue in lengths</li>
+ * <li>matches on shorter of sequences only</li>
+ * </ul>
+ */
+ public static final SimilarityParamsI PID4 = new SimilarityParams(false,
+ false, true, true);
+
+ private boolean includeGappedColumns;
+
+ private boolean matchGaps;
+
+ private boolean includeGaps;
+
+ private boolean denominateByShortestLength;
+
+ /**
+ * Constructor
+ *
+ * @param includeGapGap
+ * @param matchGapResidue
+ * @param includeGapResidue
+ * if true, gapped positions are counted for normalisation by length
+ * @param shortestLength
+ * if true, the denominator is the shorter sequence length (possibly
+ * including gaps)
+ */
+ public SimilarityParams(boolean includeGapGap, boolean matchGapResidue,
+ boolean includeGapResidue, boolean shortestLength)
+ {
+ includeGappedColumns = includeGapGap;
+ matchGaps = matchGapResidue;
+ includeGaps = includeGapResidue;
+ denominateByShortestLength = shortestLength;
+ }
+
+ @Override
+ public boolean includeGaps()
+ {
+ return includeGaps;
+ }
+
+ @Override
+ public boolean denominateByShortestLength()
+ {
+ return denominateByShortestLength;
+ }
+
+ @Override
+ public boolean includeGappedColumns()
+ {
+ return includeGappedColumns;
+ }
+
+ @Override
+ public boolean matchGaps()
+ {
+ return matchGaps;
+ }
+}