avoid string expr in to_next_multiple

qupulse/utils/__init__.py

@@ -13,6 +13,7 @@
 from qupulse.expressions import ExpressionScalar, ExpressionLike
 
 import numpy
+import sympy as sp
 
 try:
     from math import isclose
@@ -151,6 +152,22 @@ def to_next_multiple(sample_rate: ExpressionLike, quantum: int,
         #double negative for ceil division.
         return lambda duration: -(-(duration*sample_rate)//quantum) * (quantum/sample_rate)
     else:
-        #still return 0 if duration==0
-        return lambda duration: ExpressionScalar(f'{quantum}/({sample_rate})*Max({min_quanta},-(-({duration})*{sample_rate}//{quantum}))*Max(0, sign({duration}))')
-
+        qI  = sp.Integer(quantum)
+        k   = qI / sample_rate  # factor to go from #quanta -> duration
+        mqI = sp.Integer(min_quanta)
+
+        def _build_sym(d):
+            u  = d*sample_rate/qI                # "duration in quanta" (real)
+            ce = sp.ceiling(u)          # number of quanta after rounding up
+
+            # Enforce: 0 if d <= 0; else at least mqI quanta.
+            # max(mqI, ceil(u))  <=>  mqI if u <= mqI, else ceil(u)
+            # do not evaluate right now because parameters could still be variable,
+            # then it's just overhead.
+            return sp.Piecewise(
+                (0,  sp.Le(d, 0)),
+                (k*mqI, sp.Le(u, mqI)),
+                (k*ce, True)
+            , evaluate=False)
+
+        return lambda duration: ExpressionScalar(_build_sym(duration))

tests/utils/utils_tests.py

@@ -108,6 +108,7 @@ class ToNextMultipleTests(unittest.TestCase):
     def test_to_next_multiple(self):
         from qupulse.utils.types import TimeType
         from qupulse.expressions import ExpressionScalar
+        precision_digits = 12
 
         duration = TimeType.from_float(47.1415926535)
         evaluated = to_next_multiple(sample_rate=TimeType.from_float(2.4),quantum=16)(duration)
@@ -120,31 +121,32 @@ def test_to_next_multiple(self):
         self.assertEqual(evaluated, expected)
 
         duration = 6185240.0000001
-        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=13)(duration)
+        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=13)(duration).evaluate_numeric()
         expected = 6185248
-        self.assertEqual(evaluated, expected)
+        self.assertAlmostEqual(evaluated, expected, precision_digits)
+
+        duration = 63.99
+        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=4)(duration).evaluate_numeric()
+        expected = 64
+        self.assertAlmostEqual(evaluated, expected, precision_digits)
+
+        duration = 64.01
+        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=4)(duration).evaluate_numeric()
+        expected = 80
+        self.assertAlmostEqual(evaluated, expected, precision_digits)
 
         duration = 0.
-        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=13)(duration)
+        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=13)(duration).evaluate_numeric()
         expected = 0.
-        self.assertEqual(evaluated, expected)
+        self.assertAlmostEqual(evaluated, expected, precision_digits)
 
         duration = ExpressionScalar('abc')
         evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=13)(duration).evaluate_in_scope(dict(abc=0.))
         expected = 0.
-        self.assertEqual(evaluated, expected)
+        self.assertAlmostEqual(evaluated, expected, precision_digits)
 
         duration = ExpressionScalar('q')
         evaluated = to_next_multiple(sample_rate=ExpressionScalar('w'),quantum=16,min_quanta=1)(duration).evaluate_in_scope(
                         dict(q=3.14159,w=1.0))
         expected = 16.
-        self.assertEqual(evaluated, expected)
-
-        #bracket silent bug
-        duration = ExpressionScalar('51 + q*51')
-        evaluated = to_next_multiple(sample_rate=1.0,quantum=16,min_quanta=1)(duration).evaluate_in_scope(
-                        dict(q=3.14159,))
-        expected = 224.
-        self.assertEqual(evaluated, expected)
-
-
+        self.assertAlmostEqual(evaluated, expected, precision_digits)