Merge branch 'release-0.14.10'. Refs #302.

Author: ivanperez-keera

yampa-test/CHANGELOG

@@ -1,3 +1,7 @@
+2024-08-07 Ivan Perez <ivan.perez@keera.co.uk>
+    * Version bump (0.14.10) (#302).
+    * Add test for trapezoidIntegral (#263).
+
 2024-06-08 Ivan Perez <ivan.perez@keera.co.uk>
     * Version bump (0.14.9) (#299).
 

yampa-test/tests/Test/FRP/Yampa/Integration.hs

@@ -27,6 +27,8 @@ tests = testGroup "Regression tests for FRP.Yampa.Integration"
   , testProperty "imIntegral (0, qc)"         testImIntegral0
   , testProperty "imIntegral (1, qc)"         testImIntegral1
   , testProperty "imIntegral (2, qc)"         testImIntegral2
+  , testProperty "trapezoidIntegral (0, qc)"  testTrapezoidIntegral0
+  , testProperty "trapezoidIntegral (1, qc)"  testTrapezoidIntegral1
   , testProperty "impulseIntegral (0, fixed)" (property $ utils_t7 ~= utils_t7r)
   , testProperty "count (0, fixed)"           (property $ utils_t4 ~= utils_t4r)
   , testProperty "count (1, fixed)"           (property $ utils_t5 ~= utils_t5r)
@@ -149,6 +151,40 @@ testImIntegral2 =
 
     close (x,y) = abs (x-y) < 0.05
 
+testTrapezoidIntegral0 :: Property
+testTrapezoidIntegral0 =
+    forAll myStream $ evalT $
+      Next $ Always $ prop ((sf &&& sfByHand), const close)
+
+  where
+    myStream :: Gen (SignalSampleStream Double)
+    myStream = uniDistStream
+
+    sf :: SF Double Double
+    sf = trapezoidIntegral >>> derivative
+
+    sfByHand :: SF Double Double
+    sfByHand = (identity &&& iPre 0) >>^ (\(x, y) -> (x + y) / 2)
+
+    close (x,y) = abs (x-y) < 0.05
+
+testTrapezoidIntegral1 :: Property
+testTrapezoidIntegral1 =
+    forAll myStream $ evalT $
+      Next $ Always $ prop ((sf &&& sfByHand), const close)
+
+  where
+    myStream :: Gen (SignalSampleStream Double)
+    myStream = uniDistStream
+
+    sf :: SF Double Double
+    sf = arr (*2) >>> trapezoidIntegral
+
+    sfByHand :: SF Double Double
+    sfByHand = trapezoidIntegral >>> arr (*2)
+
+    close (x,y) = abs (x-y) < 0.05
+
 utils_t7 :: [Double]
 utils_t7 = take 50 $ embed impulseIntegral
                            (deltaEncode 0.1 (zip (repeat 1.0) evSeq))

yampa-test/yampa-test.cabal

@@ -31,7 +31,7 @@ cabal-version: >= 1.10
 build-type:    Simple
 
 name:          yampa-test
-version:       0.14.9
+version:       0.14.10
 author:        Ivan Perez
 maintainer:    ivan.perez@keera.co.uk
 homepage:      http://github.com/ivanperez-keera/Yampa
@@ -84,7 +84,7 @@ library
       base               >= 4       && < 5
     , normaldistribution >= 1.1.0.1 && < 1.2
     , QuickCheck         >= 2.12    && < 2.15
-    , Yampa              >= 0.14.9  && < 0.15
+    , Yampa              >= 0.14.10 && < 0.15
 
   default-language:
     Haskell2010

yampa/CHANGELOG

@@ -1,3 +1,7 @@
+2024-08-07 Ivan Perez <ivan.perez@keera.co.uk>
+    * Version bump (0.14.10) (#302).
+    * Implement integral using trapezoid rule (#263).
+
 2024-06-08 Ivan Perez <ivan.perez@keera.co.uk>
     * Version bump (0.14.9) (#299).
     * Document FRP.Yampa.Random.streamToSF (#296).

yampa/Yampa.cabal

@@ -30,7 +30,7 @@ cabal-version: >= 1.10
 build-type:    Simple
 
 name:          Yampa
-version:       0.14.9
+version:       0.14.10
 author:        Henrik Nilsson, Antony Courtney
 maintainer:    Ivan Perez (ivan.perez@keera.co.uk)
 homepage:      https://github.com/ivanperez-keera/Yampa/

yampa/src/FRP/Yampa.hs

@@ -280,6 +280,7 @@ module FRP.Yampa
       -- ** Integration and differentiation
     , integral
     , imIntegral
+    , trapezoidIntegral
     , impulseIntegral
     , count
     , derivative

yampa/src/FRP/Yampa/Integration.hs

@@ -32,6 +32,7 @@ module FRP.Yampa.Integration
       -- * Integration
       integral
     , imIntegral
+    , trapezoidIntegral
     , impulseIntegral
     , count
 
@@ -71,6 +72,12 @@ integral = SF {sfTF = tf0}
 imIntegral :: (Fractional s, VectorSpace a s) => a -> SF a a
 imIntegral = ((\_ a' dt v -> v ^+^ realToFrac dt *^ a') `iterFrom`)
 
+-- | Trapezoid integral (using the average between the value at the last time
+-- and the value at the current time).
+trapezoidIntegral :: (Fractional s, VectorSpace a s) => SF a a
+trapezoidIntegral =
+  iterFrom (\a a' dt v -> v ^+^ (realToFrac dt / 2) *^ (a ^+^ a')) zeroVector
+
 -- | Integrate the first input signal and add the /discrete/ accumulation (sum)
 -- of the second, discrete, input signal.
 impulseIntegral :: (Fractional k, VectorSpace a k) => SF (a, Event a) a