Show R-R intervals in ms instead of s.

2 files changed, 13 insertions, 11 deletions

diff --git a/lib/postrunner/ChartView.rb b/lib/postrunner/ChartView.rb
index b146ea4..8009954 100644
--- a/lib/postrunner/ChartView.rb
+++ b/lib/postrunner/ChartView.rb
@@ -46,7 +46,7 @@ module PostRunner
       chart_div(doc, 'altitude', "Elevation (#{select_unit('m')})")
       chart_div(doc, 'heart_rate', 'Heart Rate (bpm)')
       if @hrv_analyzer.has_hrv_data?
-        chart_div(doc, 'hrv', 'Heart Rate Variability (s)')
+        chart_div(doc, 'hrv', 'R-R Intervals/Heart Rate Variability (ms)')
         #chart_div(doc, 'hrv_score', 'HRV Score (30s Window)')
       end
       chart_div(doc, 'run_cadence', 'Run Cadence (spm)')
@@ -187,9 +187,10 @@ EOT
           prev_intvl = @hrv_analyzer.rr_intervals[idx - 1]
           next unless curr_intvl && prev_intvl
 
-          dt = curr_intvl - prev_intvl
+          # Convert the R-R interval duration to ms.
+          dt = (curr_intvl - prev_intvl) * 1000.0
           min_value = dt if min_value.nil? || min_value > dt
-          data_set << [ @hrv_analyzer.timestamps[idx] * 1000, dt]
+          data_set << [ @hrv_analyzer.timestamps[idx] * 1000, dt ]
         end
       else
         @activity.fit_activity.records.each do |r|
diff --git a/lib/postrunner/HRV_Analyzer.rb b/lib/postrunner/HRV_Analyzer.rb
index 8375a9b..664f7c9 100644
--- a/lib/postrunner/HRV_Analyzer.rb
+++ b/lib/postrunner/HRV_Analyzer.rb
@@ -130,6 +130,14 @@ module PostRunner
     private
 
     def collect_rr_intervals
+      # The rr_intervals Array stores the beat-to-beat time intervals (R-R).
+      # If one or move beats have been skipped during measurement, a nil value
+      # is inserted.
+      @rr_intervals = []
+      # The timestamps Array stores the relative (to start of sequence) time
+      # for each interval in the rr_intervals Array.
+      @timestamps = []
+
       # Each Fit4Ruby::HRV object has an Array called 'time' that contains up
       # to 5 R-R interval durations. If less than 5 are present, they are
       # filled with nil.
@@ -137,19 +145,12 @@ module PostRunner
       @fit_file.hrv.each do |hrv|
         raw_rr_intervals += hrv.time.compact
       end
+      return if raw_rr_intervals.empty?
 
       window = 20
       intro_mean = raw_rr_intervals[0..4 * window].reduce(:+) / (4 * window)
       predictor = LinearPredictor.new(window, intro_mean)
 
-      # The rr_intervals Array stores the beat-to-beat time intervals (R-R).
-      # If one or move beats have been skipped during measurement, a nil value
-      # is inserted.
-      @rr_intervals = []
-      # The timestamps Array stores the relative (to start of sequence) time
-      # for each interval in the rr_intervals Array.
-      @timestamps = []
-
       # The timer accumulates the interval durations.
       timer = 0.0
       raw_rr_intervals.each do |dt|