add --min_as option to convolute

src/pineko/cli/convolute.py

@@ -17,6 +17,7 @@
 @click.argument("max_al", type=int)
 @click.option("--xir", default=1.0, help="renormalization scale variation")
 @click.option("--xif", default=1.0, help="factorization scale variation")
+@click.option("--min_as", type=int, help="Minimum exponent of as")
 @click.option(
     "--pdf", default=None, help="if given, print comparison table", show_default=True
 )
@@ -26,14 +27,18 @@
     help="the flavor assumptions to be used",
     show_default=True,
 )
-def subcommand(grid_path, op_path, fktable, max_as, max_al, xir, xif, pdf, assumptions):
+def subcommand(
+    grid_path, op_path, fktable, max_as, max_al, xir, xif, pdf, assumptions, min_as
+):
     """Convolute PineAPPL grid and EKO into an FK table.
 
     GRID_PATH and OP_PATH are the path to the respective elements to convolute, and
     FKTABLE is the path where to dump the output.
 
     MAX_AS and MAX_AL are used to specify the order in QCD and QED
-    couplings (i.e. the maximum power allowed for each correction).
+    couplings (i.e. the maximum power allowed for each correction)
+    e.g., max_as = 1, max_al = 0 would select LO QCD only
+    max_as = 3 instead would select LO, NLO, NNLO QCD
 
     XIR and XIF represent the renormalization and factorization scale in the grid respectively.
 
@@ -49,6 +54,7 @@ def subcommand(grid_path, op_path, fktable, max_as, max_al, xir, xif, pdf, assum
             f"+ {op_path}\n",
             f"= {fktable}\n",
             f"with max_as={max_as}, max_al={max_al}, xir={xir}, xif={xif}",
+            f"min_as: {min_as}" if min_as is not None else "",
         )
         _grid, _fk, comp = evolve.evolve_grid(
             grid,
@@ -60,6 +66,7 @@ def subcommand(grid_path, op_path, fktable, max_as, max_al, xir, xif, pdf, assum
             xif,
             assumptions=assumptions,
             comparison_pdf=pdf,
+            min_as=min_as,
         )
         if comp:
             print(comp.to_string())

src/pineko/evolve.py

@@ -190,6 +190,7 @@ def evolve_grid(
     assumptions="Nf6Ind",
     comparison_pdf=None,
     meta_data=None,
+    min_as=None,
 ):
     """Convolute grid with EKO from file paths.
 
@@ -215,8 +216,18 @@ def evolve_grid(
         if given, a comparison table (with / without evolution) will be printed
     meta_data : None or dict
         if given, additional meta data written to the FK table
+    min_as: None or int
+        minimum power of strong coupling
     """
     order_mask = pineappl.grid.Order.create_mask(grid.orders(), max_as, max_al, True)
+    if min_as is not None and min_as > 1:
+        # If using min_as, we want to ignore only orders below that (e.g., if min_as=2
+        # and max_as=3, we want NNLO and NLO)
+        ignore_orders = pineappl.grid.Order.create_mask(
+            grid.orders(), min_as - 1, max_al, True
+        )
+        order_mask ^= ignore_orders
+
     evol_info = grid.evolve_info(order_mask)
     x_grid = evol_info.x1
     mur2_grid = evol_info.ren1