Allow forcing global query sketch

marbl · Oct 11, 2024 · 385edae · 385edae
1 parent 51215f5
commit 385edae
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Showing 3 changed files with 19 additions and 11 deletions.
diff --git a/src/map/include/computeMap.hpp b/src/map/include/computeMap.hpp
@@ -818,15 +818,22 @@ namespace skch
         void getSeedHits(Q_Info &Q)
         {
           Q.minmerTableQuery.reserve(param.sketchSize + 1);
-          if (Q.len > 1.5 * param.segLength)
+
+          // Use global sketch of param.sketchSize if 
+          // (a) We are splitting the query into segments
+          // (b) We are not splitting the query, but we want unbiased Jaccard 
+          // (c) We are not splitting the query, but it isn't even longer than param.segLength
+          if (param.split 
+              || param.forceGlobalQuerySketch
+              || Q.len <= param.segLength)
           {
-            CommonFunc::addMinmers(Q.minmerTableQuery, Q.seq, Q.len, param.kmerSize, param.segLength, param.alphabetSize, param.sketchSize, Q.seqCounter);
-            std::sort(Q.minmerTableQuery.begin(), Q.minmerTableQuery.end(), [](const MinmerInfo& l, const MinmerInfo& r) {return l.hash < r.hash;});
-            Q.minmerTableQuery.erase(std::unique(Q.minmerTableQuery.begin(), Q.minmerTableQuery.end()), Q.minmerTableQuery.end());
+            CommonFunc::sketchSequence(Q.minmerTableQuery, Q.seq, Q.len, param.kmerSize, param.alphabetSize, param.sketchSize, Q.seqCounter);
           }
           else
           {
-            CommonFunc::sketchSequence(Q.minmerTableQuery, Q.seq, Q.len, param.kmerSize, param.alphabetSize, param.sketchSize, Q.seqCounter);
+            CommonFunc::addMinmers(Q.minmerTableQuery, Q.seq, Q.len, param.kmerSize, param.segLength, param.alphabetSize, param.sketchSize, Q.seqCounter);
+            std::sort(Q.minmerTableQuery.begin(), Q.minmerTableQuery.end(), [](const MinmerInfo& l, const MinmerInfo& r) {return l.hash < r.hash;});
+            Q.minmerTableQuery.erase(std::unique(Q.minmerTableQuery.begin(), Q.minmerTableQuery.end()), Q.minmerTableQuery.end());
           }
           if(Q.minmerTableQuery.size() == 0) {
             Q.sketchSize = 0;

diff --git a/src/map/include/map_parameters.hpp b/src/map/include/map_parameters.hpp
@@ -54,6 +54,7 @@ struct Parameters
     stdfs::path saveIndexFilename;                    //output file name of index
     stdfs::path loadIndexFilename;                    //input file name of index
     bool split;                                       //Split read mapping (done if this is true)
+    bool forceGlobalQuerySketch;                      //Use the minhash sketch for entire query even if --noSplit is used
     bool lower_triangular;                            // set to true if we should filter out half of the mappings
     bool skip_self;                                   //skip self mappings
     bool skip_prefix;                                 //skip mappings to sequences with the same prefix

diff --git a/src/map/include/parseCmdArgs.hpp b/src/map/include/parseCmdArgs.hpp
@@ -60,7 +60,7 @@ sequences shorter than segment length will be ignored", ArgvParser::OptionRequir
     cmd.defineOption("sketchSize", "Number of sketch elements", ArgvParser::OptionRequiresValue);
     cmd.defineOptionAlternative("sketchSize","J");
 
-    cmd.defineOption("dense", "Use dense sketching to yield higher ANI estimation accuracy. [disabled by default]");
+    cmd.defineOption("dense", "Use dense sketching to yield higher ANI estimation accuracy.");
 
     cmd.defineOption("blockLength", "keep merged mappings supported by homologies of at least this length [default: segmentLength]", ArgvParser::OptionRequiresValue);
     cmd.defineOptionAlternative("blockLength", "l");
@@ -77,7 +77,8 @@ sequences shorter than segment length will be ignored", ArgvParser::OptionRequir
     cmd.defineOption("loadIndex", "Prefix of index files to load, where PREFIX.map and PREFIX.index are the files to be loaded", ArgvParser::OptionRequiresValue);
 
 
-    cmd.defineOption("noSplit", "disable splitting of input sequences during mapping [enabled by default]");
+    cmd.defineOption("noSplit", "disable splitting of input sequences during mapping");
+    cmd.defineOption("unbiasedNoSplit", "same as noSplit, but uses same sketch size for each query, regardless of length. This leads to unbiased Jaccard prediction and faster mappings at a potential loss in mapping accuracy.");
 
     cmd.defineOption("perc_identity", "threshold for identity [default : 85]", ArgvParser::OptionRequiresValue);
     cmd.defineOptionAlternative("perc_identity","pi");
@@ -416,16 +417,15 @@ sequences shorter than segment length will be ignored", ArgvParser::OptionRequir
     else
       parameters.filterMode = filter::MAP;
 
-    if(cmd.foundOption("noSplit"))
+    parameters.forceGlobalQuerySketch = cmd.foundOption("unbiasedNoSplit");
+    parameters.split = !cmd.foundOption("noSplit") && !cmd.foundOption("unbiasedNoSplit");
+    if(!parameters.split)
     {
-      parameters.split = false;
       if (parameters.stage1_topANI_filter)
         std::cerr << "WARNING, skch::parseandSave, hypergeometric filter is incompatible with --noSplit. Disabling hypergeometric filter." << std::endl;
 
       parameters.stage1_topANI_filter = false;
     }
-    else
-      parameters.split = true;
 
     if(cmd.foundOption("noMerge"))
     {