round TimestampedAnnotationList fields to nearest representable EDF v…

…alue (#38)

Co-authored-by: Alex Arslan <[email protected]>

Project.toml

@@ -1,7 +1,7 @@
 name = "EDF"
 uuid = "ccffbfc1-f56e-50fb-a33b-53d1781b2825"
 authors = ["Beacon Biosignals, Inc."]
-version = "0.5.1"
+version = "0.6.0"
 
 [deps]
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"

src/types.jl

@@ -82,6 +82,12 @@ const ANNOTATIONS_SIGNAL_LABEL = "EDF Annotations"
 
 A type representing a time-stamped annotations list (TAL).
 
+Note that this type's constructor may attempt to round given `onset_in_seconds` and
+`duration_in_seconds` arguments to their nearest representable values in accordance
+with the EDF+ specification, which a) represents these values as ASCII, b) constrains
+these values to an 8 character limit, and c) does not allow the use of scientific
+notation for these fields.
+
 See EDF+ specification for details.
 
 # Fields
@@ -94,6 +100,17 @@ struct TimestampedAnnotationList
     onset_in_seconds::Float64
     duration_in_seconds::Union{Float64,Nothing}
     annotations::Vector{String}
+    function TimestampedAnnotationList(onset_in_seconds, duration_in_seconds, annotations)
+        onset_in_seconds = _nearest_representable_edf_time_value(onset_in_seconds)
+        duration_in_seconds = _nearest_representable_edf_time_value(duration_in_seconds)
+        return new(onset_in_seconds, duration_in_seconds, annotations)
+    end
+end
+
+_nearest_representable_edf_time_value(::Nothing) = nothing
+
+function _nearest_representable_edf_time_value(x)
+    return round(x; digits=(8 - (ndigits(floor(Int, x)) + signbit(x) + isinteger(x))))
 end
 
 function Base.:(==)(a::TimestampedAnnotationList, b::TimestampedAnnotationList)

test/runtests.jl

@@ -107,6 +107,13 @@ const DATADIR = joinpath(@__DIR__, "data")
         @test eof(io)
     end
 
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(-0.0023405432)) == "-0.00234"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(0.0023405432)) == "0.002340"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(1.002343)) == "1.002343"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(1011.05432)) == "1011.054"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(-1011.05432)) == "-1011.05"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(-1013441.5)) == "-1013442"
+    @test EDF._edf_repr(EDF._nearest_representable_edf_time_value(-1013441.3)) == "-1013441"
     @test EDF._edf_repr(34577777) == "34577777"
     @test EDF._edf_repr(0.0345) == "0.034500"
     @test EDF._edf_repr(-0.02) == "-0.02000"