[MRG] Doing bounds checking on --scaled via command line

src/sourmash/cli/gather.py

@@ -1,7 +1,7 @@
 """search a metagenome signature against dbs"""
 
 from sourmash.cli.utils import (add_ksize_arg, add_moltype_args,
-                                add_picklist_args)
+                                add_picklist_args, add_scaled_arg)
 
 
 def subparser(subparsers):
@@ -45,10 +45,6 @@ def subparser(subparsers):
         help='output unassigned portions of the query as a signature to the '
         'specified file'
     )
-    subparser.add_argument(
-        '--scaled', metavar='FLOAT', type=float, default=0,
-        help='downsample query to the specified scaled factor'
-    )
     subparser.add_argument(
         '--ignore-abundance',  action='store_true',
         help='do NOT use k-mer abundances if present'
@@ -82,6 +78,7 @@ def subparser(subparsers):
     add_ksize_arg(subparser, 31)
     add_moltype_args(subparser)
     add_picklist_args(subparser)
+    add_scaled_arg(subparser, 0)
 
 
 def main(args):

src/sourmash/cli/index.py

@@ -26,7 +26,7 @@
 """
 
 from sourmash.cli.utils import (add_ksize_arg, add_moltype_args,
-                                add_picklist_args)
+                                add_picklist_args, add_scaled_arg)
 
 
 def subparser(subparsers):
@@ -66,13 +66,10 @@ def subparser(subparsers):
         help='What percentage of internal nodes will not be saved; ranges '
         'from 0.0 (save all nodes) to 1.0 (no nodes saved)'
     )
-    subparser.add_argument(
-        '--scaled', metavar='FLOAT', type=float, default=0,
-        help='downsample signatures to the specified scaled factor'
-    )
     add_ksize_arg(subparser, 31)
     add_moltype_args(subparser)
     add_picklist_args(subparser)
+    add_scaled_arg(subparser, 0)
 
 
 def main(args):

src/sourmash/cli/multigather.py

@@ -1,6 +1,6 @@
 "'sourmash multigather' - gather many signatures against multiple databases."
 
-from sourmash.cli.utils import add_ksize_arg, add_moltype_args
+from sourmash.cli.utils import add_ksize_arg, add_moltype_args, add_scaled_arg
 
 
 def subparser(subparsers):
@@ -28,16 +28,13 @@ def subparser(subparsers):
         '--threshold-bp', metavar='REAL', type=float, default=5e4,
         help='threshold (in bp) for reporting results (default=50,000)'
     )
-    subparser.add_argument(
-        '--scaled', metavar='FLOAT', type=float, default=0,
-        help='downsample query to the specified scaled factor'
-    )
     subparser.add_argument(
         '--ignore-abundance',  action='store_true',
         help='do NOT use k-mer abundances if present'
     )
     add_ksize_arg(subparser, 31)
     add_moltype_args(subparser)
+    add_scaled_arg(subparser, 0)
 
 
 def main(args):

src/sourmash/cli/prefetch.py

@@ -1,7 +1,7 @@
 """search a signature against dbs, find all overlaps"""
 
 from sourmash.cli.utils import (add_ksize_arg, add_moltype_args,
-                                add_picklist_args)
+                                add_picklist_args, add_scaled_arg)
 
 
 def subparser(subparsers):
@@ -54,17 +54,14 @@ def subparser(subparsers):
         help='output matching query hashes as a signature to the '
         'specified file'
     )
-    subparser.add_argument(
-        '--scaled', metavar='FLOAT', type=float, default=None,
-        help='downsample signatures to the specified scaled factor'
-    )
     subparser.add_argument(
         '--md5', default=None,
         help='select the signature with this md5 as query'
     )
     add_ksize_arg(subparser, 31)
     add_moltype_args(subparser)
     add_picklist_args(subparser)
+    add_scaled_arg(subparser, 0)
 
 
 def main(args):

src/sourmash/cli/search.py

@@ -1,7 +1,7 @@
 """search a signature against other signatures"""
 
 from sourmash.cli.utils import (add_ksize_arg, add_moltype_args,
-                                add_picklist_args)
+                                add_picklist_args, add_scaled_arg)
 
 
 def subparser(subparsers):
@@ -46,10 +46,6 @@ def subparser(subparsers):
         help='do NOT use k-mer abundances if present; note: has no effect if '
         '--containment or --max-containment is specified'
     )
-    subparser.add_argument(
-        '--scaled', metavar='FLOAT', type=float, default=0,
-        help='downsample query to this scaled factor (yields greater speed)'
-    )
     subparser.add_argument(
         '-o', '--output', metavar='FILE',
         help='output CSV containing matches to this file'
@@ -61,6 +57,7 @@ def subparser(subparsers):
     add_ksize_arg(subparser, 31)
     add_moltype_args(subparser)
     add_picklist_args(subparser)
+    add_scaled_arg(subparser, 0)
 
 
 def main(args):

src/sourmash/cli/utils.py

@@ -1,6 +1,7 @@
 from glob import glob
 import os
 import argparse
+from sourmash.logging import notify
 
 
 def add_moltype_args(parser):
@@ -93,3 +94,26 @@ def command_list(dirpath):
     basenames = [os.path.splitext(path)[0] for path in filenames if not path.startswith('__')]
     basenames = filter(opfilter, basenames)
     return sorted(basenames)
+
+
+def check_scaled_bounds(arg):
+    actual_min_val = 0
+    min_val = 100
+    max_val = 1e6
+
+    f = float(arg)
+
+    if f < actual_min_val:
+        raise argparse.ArgumentTypeError(f"ERROR: --scaled value must be positive")
+    if f < min_val:
+        notify('WARNING: --scaled value should be >= 100. Continuing anyway.')
+    if f > max_val:
+        notify('WARNING: --scaled value should be <= 1e6. Continuing anyway.')
+    return f
+
+
+def add_scaled_arg(parser, default=None):
+    parser.add_argument(
+        '--scaled', metavar='FLOAT', type=check_scaled_bounds,
+        help='scaled value should be between 100 and 1e6; default={d}'
+    )

src/sourmash/commands.py

@@ -390,6 +390,7 @@ def index(args):
 
             if args.scaled:
                 ss.minhash = ss.minhash.downsample(scaled=args.scaled)
+
             if ss.minhash.track_abundance:
                 ss.minhash = ss.minhash.flatten()
             scaleds.add(ss.minhash.scaled)
@@ -450,15 +451,13 @@ def search(args):
                                              query.minhash.ksize,
                                              sourmash_args.get_moltype(query))
 
-    # downsample if requested
     if args.scaled:
         if not query.minhash.scaled:
             error('cannot downsample a signature not created with --scaled')
             sys.exit(-1)
-
         if args.scaled != query.minhash.scaled:
             notify('downsampling query from scaled={} to {}',
-                   query.minhash.scaled, int(args.scaled))
+            query.minhash.scaled, int(args.scaled))
         query.minhash = query.minhash.downsample(scaled=args.scaled)
 
     # set up the search databases
@@ -646,10 +645,9 @@ def gather(args):
         error('query signature needs to be created with --scaled')
         sys.exit(-1)
 
-    # downsample if requested
     if args.scaled:
         notify('downsampling query from scaled={} to {}',
-               query.minhash.scaled, int(args.scaled))
+        query.minhash.scaled, int(args.scaled))
         query.minhash = query.minhash.downsample(scaled=args.scaled)
 
     # empty?
@@ -868,12 +866,11 @@ def multigather(args):
                 error('query signature needs to be created with --scaled; skipping')
                 continue
 
-            # downsample if requested
             if args.scaled:
                 notify('downsampling query from scaled={} to {}',
-                       query.minhash.scaled, int(args.scaled))
+                query.minhash.scaled, int(args.scaled))
                 query.minhash = query.minhash.downsample(scaled=args.scaled)
-
+ 
             # empty?
             if not len(query.minhash):
                 error('no query hashes!? skipping to next..')
@@ -1137,7 +1134,6 @@ def prefetch(args):
     if query_mh.track_abundance:
         query_mh = query_mh.flatten()
 
-    # downsample if/as requested
     if args.scaled:
         notify(f'downsampling query from scaled={query_mh.scaled} to {int(args.scaled)}')
         query_mh = query_mh.downsample(scaled=args.scaled)

tests/test_prefetch.py

@@ -390,6 +390,48 @@ def test_prefetch_no_db(runtmp, linear_gather):
     assert "ERROR: no databases or signatures to search!?" in c.last_result.err
 
 
+def test_prefetch_check_scaled_bounds_negative(runtmp, linear_gather):
+    c = runtmp
+
+    sig2 = utils.get_test_data('2.fa.sig')
+    sig47 = utils.get_test_data('47.fa.sig')
+    sig63 = utils.get_test_data('63.fa.sig')
+
+    with pytest.raises(ValueError) as exc:
+        c.run_sourmash('prefetch', '-k', '31', sig47, sig63, sig2, sig47,
+                    '--scaled', '-5', linear_gather)
+
+    assert "ERROR: --scaled value must be positive" in str(exc.value)
+
+
+def test_prefetch_check_scaled_bounds_less_than_minimum(runtmp, linear_gather):
+    c = runtmp
+
+    sig2 = utils.get_test_data('2.fa.sig')
+    sig47 = utils.get_test_data('47.fa.sig')
+    sig63 = utils.get_test_data('63.fa.sig')
+
+    with pytest.raises(ValueError) as exc:
+        c.run_sourmash('prefetch', '-k', '31', sig47, sig63, sig2, sig47,
+                    '--scaled', '50', linear_gather)
+
+    assert "WARNING: --scaled value should be >= 100. Continuing anyway." in str(exc.value)
+
+
+def test_prefetch_check_scaled_bounds_more_than_maximum(runtmp, linear_gather):
+    c = runtmp
+
+    sig2 = utils.get_test_data('2.fa.sig')
+    sig47 = utils.get_test_data('47.fa.sig')
+    sig63 = utils.get_test_data('63.fa.sig')
+
+    with pytest.raises(ValueError) as exc:
+        c.run_sourmash('prefetch', '-k', '31', sig47, sig63, sig2, sig47,
+                    '--scaled', '1e9', linear_gather)
+
+    assert "WARNING: --scaled value should be <= 1e6. Continuing anyway." in str(exc.value)
+
+
 def test_prefetch_downsample_scaled(runtmp, linear_gather):
     c = runtmp