events/Envelope.intergrate_interval: ↑ performance x8

This patch improves the performance of 'Envelope.intergrate_interval' by
a factor of 8-10 and the performance of the tempo converter by a factor
of 5. By no longer using scipy, but our own integration calculation, we
also no longer need scipy as a dependency, which is another great
improvement.

mutwo/core_converters/tempos.py

@@ -285,7 +285,7 @@ def convert(self, event_to_convert: core_events.abc.Event) -> core_events.abc.Ev
         >>> my_tempo_converter = core_converters.TempoConverter(tempo_envelope)
         >>> my_events = core_events.SequentialEvent([core_events.SimpleEvent(d) for d in (3, 2, 5)])
         >>> my_tempo_converter.convert(my_events)
-        SequentialEvent([SimpleEvent(duration = DirectDuration(duration = 3)), SimpleEvent(duration = DirectDuration(duration = 7205759403792795/2251799813685248)), SimpleEvent(duration = DirectDuration(duration = 6))])
+        SequentialEvent([SimpleEvent(duration = DirectDuration(duration = 3)), SimpleEvent(duration = DirectDuration(duration = 3602879701896397/1125899906842624)), SimpleEvent(duration = DirectDuration(duration = 6))])
         """
         copied_event_to_convert = event_to_convert.destructive_copy()
         self._convert_event(copied_event_to_convert, core_parameters.DirectDuration(0))

mutwo/core_events/envelopes.py

@@ -4,9 +4,9 @@
 
 import bisect
 import functools
+import math
 import typing
 
-from scipy import integrate
 import ranges
 
 from mutwo import core_constants
@@ -648,7 +648,37 @@ def integrate_interval(
         :param end: End of integration interval.
         :type end: core_parameters.abc.Duration
         """
-        return integrate.quad(lambda x: self.value_at(x), start, end)[0]
+        start, end = (
+            core_events.configurations.UNKNOWN_OBJECT_TO_DURATION(t)
+            for t in (start, end)
+        )
+        if start == end:
+            return 0
+
+        point_tuple = self.time_range_to_point_tuple(ranges.Range(start, end))
+        integral = 0
+        for p0, p1 in zip(point_tuple, point_tuple[1:]):
+            t0, v0, cs0 = p0  # (absolute_time, value, curve_shape)
+            t1, v1, _ = p1
+            if (d0 := float(t1 - t0)) > 0:
+                if cs0 != 0:
+                    # See https://git.sr.ht/~marcevanstein/expenvelope/tree/cd4a3710/item/expenvelope/envelope_segment.py#L102-103
+                    A = v0 - (v1 - v0) / (math.exp(cs0) - 1)
+                    B = (v1 - v0) / (cs0 * (math.exp(cs0) - 1))
+
+                    def antiderivative(tn):
+                        # See https://git.sr.ht/~marcevanstein/expenvelope/tree/cd4a3710/item/expenvelope/envelope_segment.py#L239
+                        return A * tn + B * math.exp(cs0 * tn)
+
+                    a0, a1 = (antiderivative(i) for i in (0, 1))
+                    integral += d0 * (a1 - a0)
+                else:  # linear interpolation
+                    diff = v1 - v0 if v1 > v0 else v0 - v1
+                    square = d0 * min((v0, v1))
+                    triangle = 0.5 * d0 * diff
+                    integral += square + triangle
+
+        return float(integral)
 
     def get_average_value(
         self,

performance_tests/performance_tests.py

@@ -57,7 +57,7 @@ def test_SimultaneousEvent_split_at(self):
         split_time_list = sorted([random.uniform(0, duration) for _ in range(25)])
         e.split_at(*split_time_list)
 
-    @t(0.8, 100)
+    @t(0.17, 100)
     def test_metrize(self):
         e = sim(
             [seq([s(random.uniform(0.9, 1.2)) for _ in range(20)]) for _ in range(3)]

setup.py

@@ -31,7 +31,6 @@
     setup_requires=[],
     install_requires=[
         "numpy>=1.18, <2.00",
-        "scipy>=1.4.1, <2.0.0",
         "python-ranges>=1.2.0, <2.0.0",
         "quicktions>=1.10, <2.0",
     ],