[MRG] Fix error when --scaled 1 is set.

sourmash_lib/__init__.py

@@ -5,6 +5,7 @@
 from __future__ import print_function
 import re
 import math
-from ._minhash import MinHash, dotproduct
+from ._minhash import (MinHash, get_minhash_default_seed, get_minhash_max_hash)
 
-DEFAULT_SEED=MinHash(1,1).seed
+DEFAULT_SEED = get_minhash_default_seed()
+MAX_HASH = get_minhash_max_hash()

sourmash_lib/_minhash.pyx

@@ -12,9 +12,22 @@ from ._minhash cimport KmerMinHash, KmerMinAbundance, _hash_murmur
 import math
 
 
+# default MurmurHash seed
 cdef uint32_t MINHASH_DEFAULT_SEED = 42
 
 
+def get_minhash_default_seed():
+    return MINHASH_DEFAULT_SEED
+
+
+# we use the 64-bit hash space of MurmurHash only
+cdef uint64_t MINHASH_MAX_HASH = 2**64 - 1
+
+
+def get_minhash_max_hash():
+    return MINHASH_MAX_HASH
+
+
 cdef bytes to_bytes(s):
     if not isinstance(s, (basestring, bytes)):
         raise TypeError("Requires a string-like sequence")

sourmash_lib/commands.py

@@ -179,8 +179,9 @@ def compute(args):
     def make_estimators():
         seed = args.seed
         max_hash = 0
-        if args.scaled:
-            max_hash = 2**64 / float(args.scaled)
+        if args.scaled and args.scaled > 1:
+            max_hash = sourmash_lib.MAX_HASH / float(args.scaled)
+            max_hash = int(round(max_hash, 0))
 
         # one estimator for each ksize
         Elist = []
@@ -222,8 +223,6 @@ def save_siglist(siglist, output_fp, filename=None):
             with open(filename, 'w') as fp:
                 sig.save_signatures(siglist, fp)
 
-    notify('Computing signature for ksizes: {}', str(ksizes))
-
     if args.track_abundance:
         print('Tracking abundance of input k-mers.',
               file=sys.stderr)
@@ -705,7 +704,7 @@ def sbt_gather(args):
     orig_mins = orig_query.estimator.get_hashes()
 
     # calculate the band size/resolution R for the genome
-    R_metagenome = 2**64 / float(orig_query.estimator.max_hash)
+    R_metagenome = sourmash_lib.MAX_HASH / float(orig_query.estimator.max_hash)
 
     # define a function to do a 'best' search and get only top match.
     def find_best(tree, query):
@@ -752,7 +751,8 @@ def build_new_signature(mins):
         # based either on an explicit --scaled parameter, or on genome
         # cardinality (deprecated)
         if best_leaf.estimator.max_hash:
-            R_genome = 2**64 / float(best_leaf.estimator.max_hash)
+            R_genome = sourmash_lib.MAX_HASH / \
+              float(best_leaf.estimator.max_hash)
         elif best_leaf.estimator.hll:
             genome_size = best_leaf.estimator.hll.estimate_cardinality()
             genome_max_hash = max(found_mins)
@@ -765,7 +765,7 @@ def build_new_signature(mins):
         # pick the highest R / lowest resolution
         R_comparison = max(R_metagenome, R_genome)
 
-        new_max_hash = 2**64 / float(R_comparison)
+        new_max_hash = sourmash_lib.MAX_HASH / float(R_comparison)
         query_mins = set([ i for i in query_mins if i < new_max_hash ])
         found_mins = set([ i for i in found_mins if i < new_max_hash ])
         orig_mins = set([ i for i in orig_mins if i < new_max_hash ])

tests/test_sourmash.py

@@ -320,6 +320,44 @@ def test_do_sourmash_compute_multik_outfile():
         assert 31 in ksizes
 
 
+def test_do_sourmash_compute_with_scaled_1():
+    with utils.TempDirectory() as location:
+        testdata1 = utils.get_test_data('short.fa')
+        outfile = os.path.join(location, 'FOO.xxx')
+        status, out, err = utils.runscript('sourmash',
+                                           ['compute', '-k', '21,31',
+                                            '--scaled', '1',
+                                            testdata1, '-o', outfile],
+                                            in_directory=location)
+        assert os.path.exists(outfile)
+
+        siglist = list(signature.load_signatures(outfile))
+        assert len(siglist) == 2
+
+        max_hashes = [ x.estimator.max_hash for x in siglist ]
+        assert len(max_hashes) == 2
+        assert set(max_hashes) == { 0 }
+
+
+def test_do_sourmash_compute_with_scaled_2():
+    with utils.TempDirectory() as location:
+        testdata1 = utils.get_test_data('short.fa')
+        outfile = os.path.join(location, 'FOO.xxx')
+        status, out, err = utils.runscript('sourmash',
+                                           ['compute', '-k', '21,31',
+                                            '--scaled', '2',
+                                            testdata1, '-o', outfile],
+                                            in_directory=location)
+        assert os.path.exists(outfile)
+
+        siglist = list(signature.load_signatures(outfile))
+        assert len(siglist) == 2
+
+        max_hashes = [ x.estimator.max_hash for x in siglist ]
+        assert len(max_hashes) == 2
+        assert set(max_hashes) == set([ int(2**64 /2.) ])
+
+
 def test_do_sourmash_compute_with_scaled():
     with utils.TempDirectory() as location:
         testdata1 = utils.get_test_data('short.fa')
@@ -944,10 +982,10 @@ def test_sbt_gather_metagenome():
         testdata_sigs = glob.glob(testdata_glob)
 
         query_sig = utils.get_test_data('gather/combined.sig')
-        
+
         cmd = ['sbt_index', 'gcf_all', '-k', '21']
         cmd.extend(testdata_sigs)
-        
+
         status, out, err = utils.runscript('sourmash', cmd,
                                            in_directory=location)
 
@@ -995,37 +1033,6 @@ def test_sbt_gather_error_no_cardinality_query():
         assert "query signature needs to be created with --scaled" in err
 
 
-def test_sbt_gather_error_no_cardinality():
-    with utils.TempDirectory() as location:
-        testdata1 = utils.get_test_data('short.fa')
-        testdata2 = utils.get_test_data('short2.fa')
-        status, out, err = utils.runscript('sourmash',
-                                           ['compute', testdata1, testdata2],
-                                           in_directory=location)
-
-        status, out, err = utils.runscript('sourmash',
-                                           ['compute', testdata2,
-                                            '--scaled', '10',
-                                            '-o', 'query.fa.sig'],
-                                           in_directory=location)
-
-        status, out, err = utils.runscript('sourmash',
-                                           ['sbt_index', 'zzz',
-                                            'short.fa.sig',
-                                            'short2.fa.sig'],
-                                           in_directory=location)
-
-        assert os.path.exists(os.path.join(location, 'zzz.sbt.json'))
-
-        status, out, err = utils.runscript('sourmash',
-                                           ['sbt_gather', 'zzz',
-                                            'query.fa.sig'],
-                                           in_directory=location,
-                                           fail_ok=True)
-        assert status == -1, (status, out, err)
-        assert "Best hash match in sbt_gather has no cardinality" in err
-
-
 def test_sbt_categorize():
     with utils.TempDirectory() as location:
         testdata1 = utils.get_test_data('genome-s10.fa.gz.sig')