fixed tests, fs->r, added w, updated docs, fixed .+ elsewhere

Author: bjarthur

doc/periodogram.rst

@@ -17,6 +17,6 @@
 
     Compute Bartlett periodogram. This is equivalent to welch_pgram(s, n, 0).
 
-.. function:: spectrogram(s; n=8, m=n/2, fs=1)
+.. function:: spectrogram(s; n=length(s)/8, m=n/2, r=1, w=(n)->ones(n,1))
 
-    Compute Spectrogram based on n segments with overlap m and sampling rate fs.
+    Compute Spectrogram based on n segments with overlap m, sampling rate r, and window w.

src/DSP.jl

@@ -16,7 +16,7 @@ export
        triang, bartlett, gaussian, bartlett_hann, blackman,
        kaiser, dpss,
        # Periodogram
-       arraysplit, periodogram, welch_pgram, bartlett_pgram, spectrogram
+       arraysplit, periodogram, welch_pgram, bartlett_pgram, spectrogram,
        # FFTFilt
        fftfilt, firfilt,
        # FilterDesign

src/filter_design.jl

@@ -421,8 +421,8 @@ analogfilter(ftype::FilterType, proto::Filter) = transform_prototype(ftype, prot
 # Do bilinear transform
 bilinear(f::Filter, fs::Real) = bilinear(convert(ZPKFilter, f), fs)
 bilinear(f::ZPKFilter, fs::Real) =
-    ZPKFilter(lfill((2 + f.z / fs)./(2 - f.z / fs), length(f.p), -1),
-    (2 + f.p / fs)./(2 - f.p / fs), real(f.k * prod(2 * fs - f.z) ./ prod(2 * fs - f.p)))
+    ZPKFilter(lfill((2 .+ f.z / fs)./(2 .- f.z / fs), length(f.p), -1),
+    (2 .+ f.p / fs)./(2 .- f.p / fs), real(f.k * prod(2 * fs .- f.z) ./ prod(2 * fs .- f.p)))
 
 # Pre-warp filter frequencies for digital filtering
 prewarp(ftype::Union(Lowpass, Highpass)) = (typeof(ftype))(4*tan(pi*ftype.w/2))

src/periodogram.jl

@@ -50,11 +50,12 @@ function bartlett_pgram(s, n)
     welch_pgram(s, n, 0)
 end
 
-function spectrogram(s; n=int(length(s)/8), m=int(n/2), fs=1)
-  p=[periodogram(s) for s in arraysplit(s, n, m)]
+function spectrogram(s; n=int(length(s)/8), m=int(n/2), r=1, w=(n)->ones(n,1))
+  w=w(n)
+  p=[periodogram(s.*w) for s in arraysplit(s, n, m)]
   p=hcat(p...)
-  t=(0:size(p,2)-1)*(n-m)/fs + n/2
-  f=(0:size(p,1)-1)/size(p,1)*fs
+  t=(0:size(p,2)-1)*(n-m)/r + n/2
+  f=(0:size(p,1)-1)/size(p,1)*r
   p, t, f
 end
 

test/fftfilt.jl

@@ -1,6 +1,6 @@
 using DSP, Base.Test
 
-for xlen in 2.^(7:18)-1, blen in 2.^(1:6)-1
+for xlen in 2.^(7:18).-1, blen in 2.^(1:6).-1
 	b = randn(blen)
 	x = rand(xlen)
 	filtres = filt(b, [1.0], x)

test/periodogram.jl

@@ -16,11 +16,11 @@
 
 using DSP, Base.Test
 
-x0 = readdlm("spectrogram_x.txt",'\t')
-f0 = readdlm("spectrogram_f.txt",'\t')
-t0 = readdlm("spectrogram_t.txt",'\t')
-p0 = readdlm("spectrogram_p.txt",'\t')
-p, t, f = spectrogram(x0, nfft=256, fs=1, noverlap=128)
+x0 = readdlm(joinpath(dirname(@__FILE__), "data", "spectrogram_x.txt"),'\t')
+f0 = readdlm(joinpath(dirname(@__FILE__), "data", "spectrogram_f.txt"),'\t')
+t0 = readdlm(joinpath(dirname(@__FILE__), "data", "spectrogram_t.txt"),'\t')
+p0 = readdlm(joinpath(dirname(@__FILE__), "data", "spectrogram_p.txt"),'\t')
+p, t, f = spectrogram(x0, n=256, r=1, m=128)
 
 # with real input matlab outputs a 1-sided PSD
 @test_approx_eq p0[[1,129],:] p[[1,129],:]