Add writing to Pulseq files

This required major reformatting of the Pulseq I/O system

Closes #8 (closed)

src/sequence_io/pulseq.jl

@@ -23,24 +23,21 @@ function BuildingBlock(pulseq::PulseqBlock; version, BlockDurationRaster, Radiof
     stated_duration = pulseq.duration * BlockDurationRaster * 1e3
 
     events = []
-    min_duration = 0.
     if !isnothing(pulseq.rf)
+        f(samples) = isnothing(pulseq.rf.time) ? [samples[1], samples..., samples[end]] : samples
         if isnothing(pulseq.rf.time)
-            time = ((1:length(pulseq.rf.magnitude.samples)) .- 0.5) .* RadiofrequencyRasterTime .* 1e3
-            rf_dur = length(pulseq.rf.magnitude.samples) * RadiofrequencyRasterTime * 1e3
+            time = [0., ((1:length(pulseq.rf.magnitude.samples)) .- 0.5)..., length(pulseq.rf.magnitude.samples)] .* RadiofrequencyRasterTime .* 1e3
         else
             time = pulseq.rf.time.samples .* 1e3 * RadiofrequencyRasterTime
-            rf_dur = maximum(time)
         end
         push!(events, (
             pulseq.rf.delay * 1e-3,
             GenericPulse(
                 time, 
-                pulseq.rf.magnitude.samples * pulseq.rf.amplitude * 1e-3, 
-                rad2deg.(pulseq.rf.phase.samples .+ pulseq.rf.phase_offset .+ pulseq.rf.frequency .* time .* 2π)
+                f(pulseq.rf.magnitude.samples) * pulseq.rf.amplitude * 1e-3, 
+                rad2deg.(f(pulseq.rf.phase.samples) .+ pulseq.rf.phase_offset .+ pulseq.rf.frequency .* time .* 2π)
             )
         ))
-        min_duration = max(min_duration, events[end][1] + rf_dur)
     end
     if !isnothing(pulseq.adc)
         dwell_time = pulseq.adc.dwell * 1e-6
@@ -53,12 +50,11 @@ function BuildingBlock(pulseq::PulseqBlock; version, BlockDurationRaster, Radiof
                 1.
             )
         ))
-        min_duration = max(min_duration, events[end][1] + duration(events[end][2]))
     end
 
     grads = [pulseq.gx, pulseq.gy, pulseq.gz]
     min_duration = max(
-        min_duration,
+        maximum(e[1] + duration(e[2]) for e in events; init=0.),
         maximum(vcat(_control_times.(grads, GradientRasterTime)...); init=0.)
     )