First version of SmeftFR converter

setup.py

@@ -33,6 +33,7 @@
             'wcxf2dsixtools = wcxf.cli:wcxf2dsixtools',
             'dsixtools2wcxf = wcxf.cli:dsixtools2wcxf',
             'wcxf2smeftsim = wcxf.cli:smeftsim',
+            'wcxf2smeftfr = wcxf.cli:wcxf2smeftfr',
         ]
       },
     )

wcxf/cli.py

@@ -222,3 +222,18 @@ def dsixtools2wcxf():
     args = parser.parse_args()
     dsixtools.dsixtools2wcxf(tuple(f for f in args.FILE), stream=args.output)
     return 0
+
+
+def wcxf2smeftfr():
+    from wcxf.converters import smeftfr
+    parser = argparse.ArgumentParser(description="""Command line script to convert a WCxf file to a MadGraph param_card file for SmeftFR.""",
+                                     formatter_class=argparse.RawTextHelpFormatter)
+    parser.add_argument("FILE", nargs='?', help="Input file. If \"-\", read from standard input",
+                        type=argparse.FileType('r'), default=sys.stdin)
+    parser.add_argument("--output", nargs='?', help="Output file. If absent, print to standard output",
+                        type=argparse.FileType('w'), default=sys.stdout)
+    args = parser.parse_args()
+    wc = wcxf.WC.load(args.FILE)
+    wc.validate()
+    smeftfr.wcxf2smeftfr(wc, stream=args.output)
+    return 0

wcxf/converters/smeftfr.py

@@ -0,0 +1,45 @@
+import pylha
+import json
+import pkgutil
+from wilson.util import smeftutil
+
+
+smeftfr_info = json.loads(
+    pkgutil.get_data('wcxf', 'data/smeftfr_block_info.json').decode('utf-8')
+)
+
+
+def wcxf2smeftfr_dict(wc):
+    """Take a WC instance and turn it into a dictionary suitable for producing
+    and LHA file for SmeftFR using pylha."""
+    # go from flat dict to dict of arrays, symmetrizing them
+    C = smeftutil.wcxf2arrays_symmetrized(wc.dict)
+    # go back to flat dict but keeping non-redundant WCs an symm. fac.s
+    d = smeftutil.arrays2wcxf(C)
+    # rearrange to dict in right format for SmeftFR
+    card = {}
+    for block_name, block in smeftfr_info.items():
+        card[block_name] = {'values': []}
+        for info in block:
+            line = [*info['index'], d[info['coeff']].real, info['comment']]
+            card[block_name]['values'].append(line)
+    return card
+
+
+def wcxf2smeftfr(wc, stream):
+    """Take a WC instance and dump it into an LHA file (or return as string)
+    in a format suitable for use as `param_card.dat` file for MadGraph
+    with SmeftFR
+    """
+    if (wc.eft, wc.basis) == ('SMEFT', 'Warsaw mass'):
+        wc_m = wc
+    else:
+        if wc.eft != 'SMEFT':
+            raise ValueError("wcxf2smeftfr only support SMEFT Wilson coefficients")
+        else:
+            try:
+                wc_m = wc.translate('Warsaw mass')
+            except ValueError:
+                raise ValueError("wcxf2smeftfr requires a basis that can be translated to the Warsaw mass basis")
+    return pylha.dump({'BLOCK': wcxf2smeftfr_dict(wc_m)},
+                      fmt='lha', stream=stream)