implement reset! for FIRInterpolator and tests (#626)

* implement `reset!` for FIRInterpolator and tests

* bump version to 0.8.2

* repurpose existing test

Author: wheeheee

Project.toml

@@ -1,6 +1,6 @@
 name = "DSP"
 uuid = "717857b8-e6f2-59f4-9121-6e50c889abd2"
-version = "0.8.1"
+version = "0.8.2"
 
 [deps]
 Bessels = "0e736298-9ec6-45e8-9647-e4fc86a2fe38"

src/Filters/stream_filt.jl

@@ -244,12 +244,11 @@ setphase!(self::FIRFilter, ϕ::Real) = setphase!(self.kernel, ϕ)
 # reset! filter and its kernel to an initial state
 #
 
-# Generic case for FIRInterpolator and FIRStandard
-function reset!(kernel::FIRKernel)
+function reset!(kernel::FIRStandard)
     kernel
 end
 
-function reset!(kernel::FIRRational)
+function reset!(kernel::Union{FIRRational,FIRInterpolator})
     kernel.ϕIdx         = 1
     kernel.inputDeficit = 1
     kernel

test/resample.jl

@@ -64,9 +64,10 @@ end
     @test y_jl ≈ expected_result_3d
 
     # check buffer is resized properly (vs old implementation)
-    for dims in 1:3
+    # also test that FIRInterpolator/Decimator is reset!ed properly (issue #625)
+    for dims in 1:3, rate in (1.2, 0.8, 4, 2//1, 1//2)
         A = rand(3, 3, 3)
-        @test resample(A, 1.2; dims) == mapslices(v -> resample(v, 1.2), A; dims)
+        @test resample(A, rate; dims) == mapslices(v -> resample(v, rate), A; dims)
     end
 end