Add default values to movement model attributes.

epymorph/data/mm/centroids.movement

@@ -1,13 +1,13 @@
 [move-steps: per-day=2; duration=[1/3, 2/3]]
 
-[attrib: source=geo; name=population; shape=N; dtype=int;
-    description="The total population at each node."]
+[attrib: source=geo; name=population; shape=N; dtype=int; default_value=None;
+    comment="The total population at each node."]
 
-[attrib: source=geo; name=centroid; shape=N; dtype=[(longitude, float), (latitude, float)];
-    description="The centroids for each node as (longitude, latitude) tuples."]
+[attrib: source=geo; name=centroid; shape=N; dtype=[(longitude, float), (latitude, float)]; default_value=None;
+    comment="The centroids for each node as (longitude, latitude) tuples."]
 
-[attrib: source=params; name=phi; shape=S; dtype=float;
-    description="Influences the distance that movers tend to travel."]
+[attrib: source=params; name=phi; shape=S; dtype=float; default_value=40.0;
+    comment="Influences the distance that movers tend to travel."]
 
 [predef: function = 
 def centroids_movement():

epymorph/data/mm/flat.movement

@@ -4,11 +4,11 @@
 
 [move-steps: per-day=2; duration=[1/3, 2/3]]
 
-[attrib: source=geo; name=population; shape=N; dtype=int;
-    description="The total population at each node."]
+[attrib: source=geo; name=population; shape=N; dtype=int; default_value=None;
+    comment="The total population at each node."]
 
-[attrib: source=params; name=commuter_proportion; shape=S; dtype=float;
-    description="The ratio of the total population that is assumed to be commuters."]
+[attrib: source=params; name=commuter_proportion; shape=S; dtype=float; default_value=0.2;
+    comment="The ratio of the total population that is assumed to be commuters."]
 
 [predef: function=
 def flat_predef():

epymorph/data/mm/icecube.movement

@@ -4,8 +4,8 @@
 
 [move-steps: per-day=2; duration=[2/3, 1/3]]
 
-[attrib: source=geo; name=population; shape=N; dtype=int;
-    description="The total population at each node."]
+[attrib: source=geo; name=population; shape=N; dtype=int; default_value=None;
+    comment="The total population at each node."]
 
 [mtype: days=all; leave=1; duration=0d; return=2; function=
 def icecube(t, src):

epymorph/data/mm/no.movement

@@ -5,6 +5,6 @@
 [move-steps: per-day=1; duration=[1]]
 
 [mtype: days=all; leave=1; duration=0d; return=1; function=
-def f(t, src, dst):
+def no(t, src, dst):
     return 0
 ]

epymorph/data/mm/pei.movement

@@ -6,14 +6,14 @@
 
 [move-steps: per-day=2; duration=[1/3, 2/3]]
 
-[attrib: source=geo; name=commuters; shape=NxN; dtype=int;
-    description="A node-to-node commuters matrix."]
+[attrib: source=geo; name=commuters; shape=NxN; dtype=int; default_value=None;
+    comment="A node-to-node commuters matrix."]
 
-[attrib: source=params; name=move_control; shape=S; dtype=float;
-    description="A factor which modulates the number of commuters by conducting a binomial draw with this probability and the expected commuters from the commuters matrix."]
+[attrib: source=params; name=move_control; shape=S; dtype=float; default_value=0.9;
+    comment="A factor which modulates the number of commuters by conducting a binomial draw with this probability and the expected commuters from the commuters matrix."]
 
-[attrib: source=params; name=theta; shape=S; dtype=float;
-    description="A factor which allows for randomized movement by conducting a poisson draw with this factor times the average number of commuters between two nodes from the commuters matrix."]
+[attrib: source=params; name=theta; shape=S; dtype=float; default_value=0.1;
+    comment="A factor which allows for randomized movement by conducting a poisson draw with this factor times the average number of commuters between two nodes from the commuters matrix."]
 
 [predef: function = 
 def pei_movement():

epymorph/data/mm/sparsemod.movement

@@ -4,14 +4,14 @@
 
 [move-steps: per-day=2; duration=[1/3, 2/3]]
 
-[attrib: source=geo; name=centroid; shape=N; dtype=[(longitude, float), (latitude, float)];
-    description="The centroids for each node as (longitude, latitude) tuples."]
+[attrib: source=geo; name=centroid; shape=N; dtype=[(longitude, float), (latitude, float)]; default_value=None;
+    comment="The centroids for each node as (longitude, latitude) tuples."]
 
-[attrib: source=geo; name=commuters; shape=NxN; dtype=int;
-    description="A node-to-node commuters matrix."]
+[attrib: source=geo; name=commuters; shape=NxN; dtype=int; default_value=None;
+    comment="A node-to-node commuters matrix."]
 
-[attrib: source=params; name=phi; shape=S; dtype=float;
-    description="Influences the distance that movers tend to travel."]
+[attrib: source=params; name=phi; shape=S; dtype=float; default_value=40.0;
+    comment="Influences the distance that movers tend to travel."]
 
 [predef: function = 
 def sparsemod_predef():

epymorph/movement/parser.py

@@ -2,11 +2,14 @@
 from typing import Literal, NamedTuple, cast
 
 import pyparsing as P
+import sympy
 from numpy.typing import DTypeLike
+from pyparsing import pyparsing_common as PC
 
 import epymorph.movement.parser_util as p
 from epymorph.data_shape import DataShape
 from epymorph.error import MmParseException
+from epymorph.sympy_shim import to_symbol
 
 # A MovementSpec has the following object structure:
 #
@@ -28,7 +31,7 @@ class MoveSteps(NamedTuple):
 
 
 move_steps: P.ParserElement = p.tag('move-steps', [
-    p.field('per-day', p.integer)('num_steps'),
+    p.field('per-day', PC.integer)('num_steps'),
     p.field('duration', p.num_list)('steps')
 ])
 
@@ -49,26 +52,46 @@ class Attribute(NamedTuple):
     """The data model for an Attribute clause."""
     # TODO: maybe replace with epymorph.simulation.AttributeDef in v0.5
     name: str
-    shape: DataShape
-    dtype: DTypeLike  # TODO: replace with DataDType in v0.5?
     source: Literal['geo', 'params']
-    description: str
+    dtype: DTypeLike  # TODO: replace with DataDType in v0.5?
+    shape: DataShape
+    symbol: sympy.Symbol
+    default_value: int | float | str \
+        | tuple[int | float | str, ...] \
+        | None
+    comment: str | None
 
 
 attribute: P.ParserElement = p.tag('attrib', [
     p.field('source', P.one_of('geo params')),
     p.field('name', p.name),
     p.field('shape', p.shape),
     p.field('dtype', p.dtype),
-    p.field('description', p.quoted),
+    p.field('default_value', p.scalar_value | p.none),
+    p.field('comment', p.quoted),
 ])
 
 
 @attribute.set_parse_action
 def marshal_attribute(results: P.ParseResults):
     """Convert a pyparsing result to an Attribute."""
     fields = results.as_dict()
-    return Attribute(fields['name'], fields['shape'], fields['dtype'][0], fields['source'], fields['description'])
+    dtype = fields['dtype'][0]
+    default_value = fields['default_value'][0]
+
+    # We can coerce integers to floats for convenience.
+    if dtype == float and isinstance(default_value, int):
+        default_value = float(default_value)
+
+    return Attribute(
+        name=fields['name'],
+        source=fields['source'],
+        dtype=dtype,
+        shape=fields['shape'],
+        symbol=to_symbol(fields['name']),
+        default_value=default_value,
+        comment=fields['comment'],
+    )
 
 
 ############################################################
@@ -125,9 +148,9 @@ class DailyClause(NamedTuple):
 
 daily: P.ParserElement = p.tag('mtype', [
     p.field('days', ('all' | day_list)),
-    p.field('leave', p.integer),
+    p.field('leave', PC.integer),
     p.field('duration', p.duration),
-    p.field('return', p.integer),
+    p.field('return', PC.integer),
     p.field('function', p.fn_body)
 ])
 """

epymorph/movement/parser_util.py

@@ -6,6 +6,7 @@
 
 import numpy as np
 import pyparsing as P
+from pyparsing import pyparsing_common as PC
 
 from epymorph.data_shape import parse_shape
 
@@ -15,9 +16,14 @@
 E = P.ParserElement
 _ = P.Suppress
 l = P.Literal
-fnumber = P.pyparsing_common.fnumber
-fraction = P.pyparsing_common.fraction
-integer = P.pyparsing_common.integer
+none = l('None')
+
+
+@none.set_parse_action
+def marshal_none(_results: P.ParseResults):
+    """Marshal a None value."""
+    return P.ParseResults([None])
+
 
 quoted = P.QuotedString(quote_char='"', unquote_results=True) |\
     P.QuotedString(quote_char="'", unquote_results=True)
@@ -55,7 +61,7 @@ def combine(p1, p2):
     return bracketed(_(l(tag_name) + l(":")) - field_list)
 
 
-num_list: E = bracketed(P.delimited_list(fraction | fnumber))
+num_list: E = bracketed(P.delimited_list(PC.fraction | PC.fnumber))
 """Parser for a list of numbers in brackets, like: `[1,2,3]`"""
 
 
@@ -74,7 +80,7 @@ def to_days(self) -> int:
             raise ValueError(f"unsupported unit {self.unit}")
 
 
-duration = P.Group(integer + P.one_of('d w'))
+duration = P.Group(PC.integer + P.one_of('d w'))
 """Parser for a duration expression."""
 
 
@@ -100,6 +106,9 @@ def my_function():
 """
 
 
+# Shapes
+
+
 shape = P.one_of("S T N TxN NxN")
 """
 Describes the dimensions of an array in terms of the simulation.
@@ -117,6 +126,9 @@ def marshal_shape(results: P.ParseResults):
     return P.ParseResults(parse_shape(value))
 
 
+# dtypes
+
+
 base_dtype = P.one_of('int float str')
 """One of epymorph's base permitted data types."""
 
@@ -151,7 +163,24 @@ def marshal_struct_dtype_field(results: P.ParseResults):
 @struct_dtype.set_parse_action
 def marshal_struct_dtype(results: P.ParseResults):
     """Convert a pyparsing results to a structured dtype object."""
-    return np.dtype(results.as_list())
+    return [results.as_list()]
 
 
 dtype = base_dtype | struct_dtype
+
+
+# Scalar Values
+
+
+base_scalar = quoted | PC.number
+
+tuple_scalar = _('(') + P.delimited_list(base_scalar, ',') + _(')')
+
+
+@tuple_scalar.set_parse_action
+def marshal_tuple_scalar(results: P.ParseResults):
+    """Convert a pyparsing result to a tuple of values."""
+    return tuple(results.as_list())
+
+
+scalar_value = tuple_scalar | base_scalar

epymorph/movement/test/parser_test.py

@@ -9,6 +9,7 @@
 from epymorph.movement.parser import (Attribute, DailyClause, MoveSteps,
                                       attribute, daily, move_steps)
 from epymorph.movement.parser_util import Duration
+from epymorph.sympy_shim import to_symbol
 
 
 class TestMoveSteps(unittest.TestCase):
@@ -45,28 +46,33 @@ def test_failures(self):
 class TestAttribute(unittest.TestCase):
     def test_successful(self):
         cases = [
-            '[attrib: source=geo; name=commuters; shape=NxN; dtype=int; description="hey1"]',
-            '[attrib: source=params; name=move_control; shape=TxN; dtype=float; description="hey2"]',
-            '[attrib: source=params; name=move_control; shape=TxN; dtype=float;\n    description="hey3"]',
-            '[attrib:\nsource=params;\nname=theta;\nshape=S;\ndtype=str;\ndescription="hey4"]',
-            '[attrib: source=geo; name=centroids; shape=N; dtype=[(longitude, float), (latitude, float)]; description="hey5"]',
+            '[attrib: source=geo; name=commuters; shape=NxN; dtype=int; default_value=None; comment="hey1"]',
+            '[attrib: source=params; name=move_control; shape=TxN; dtype=float; default_value=42; comment="hey2"]',
+            '[attrib: source=params; name=move_control; shape=TxN; dtype=float; default_value=-32.7;\n    comment="hey3"]',
+            '[attrib:\nsource=params;\nname=theta;\nshape=S;\ndtype=str;\ndefault_value="hi";\ncomment="hey4"]',
+            '[attrib: source=geo; name=centroids; shape=N; dtype=[(longitude, float), (latitude, float)]; default_value=(1.0, 2.0); comment="hey5"]',
         ]
         exps = [
-            Attribute('commuters', Shapes.NxN, np.int64, 'geo', 'hey1'),
-            Attribute('move_control', Shapes.TxN, np.float64, 'params', 'hey2'),
-            Attribute('move_control', Shapes.TxN, np.float64, 'params', 'hey3'),
-            Attribute('theta', Shapes.S, np.str_, 'params', 'hey4'),
-            Attribute('centroids', Shapes.N, CentroidDType, 'geo', 'hey5'),
+            Attribute('commuters', 'geo', np.int64, Shapes.NxN,
+                      to_symbol('commuters'), None, 'hey1'),
+            Attribute('move_control', 'params', np.float64, Shapes.TxN,
+                      to_symbol('move_control'), 42.0, 'hey2'),
+            Attribute('move_control', 'params', np.float64, Shapes.TxN,
+                      to_symbol('move_control'), -32.7, 'hey3'),
+            Attribute('theta', 'params', np.str_, Shapes.S,
+                      to_symbol('theta'), 'hi', 'hey4'),
+            Attribute('centroids', 'geo', CentroidDType, Shapes.N,
+                      to_symbol('centroids'), (1.0, 2.0), 'hey5'),
         ]
         for c, e in zip(cases, exps):
             a = attribute.parse_string(c)[0]
             self.assertEqual(a, e, f"{str(a)} did not match {str(e)}")
 
     def test_failures(self):
         cases = [
-            '[attrib: source=blah; name=commuters; shape=NxN; dtype=int; description="hey1"]',
-            '[attrib: source=params; name=move_control; shape=TxN; dtype=uint8; description="hey2"]',
-            '[attrib: source=params; name=move_control; shape=TxA; dtype=float; description="hey3"]',
+            '[attrib: source=blah; name=commuters; shape=NxN; dtype=int; default_value=23; comment="hey1"]',
+            '[attrib: source=params; name=move_control; shape=TxN; dtype=uint8; default_value=1; comment="hey2"]',
+            '[attrib: source=params; name=move_control; shape=TxA; dtype=float; default_value=27.3; comment="hey3"]',
         ]
         for c in cases:
             with self.assertRaises(ParseBaseException):