New: Include heart rate zone in activity reports.

3 files changed, 160 insertions, 3 deletions

diff --git a/lib/postrunner/ActivitySummary.rb b/lib/postrunner/ActivitySummary.rb
index 97df15d..2ec4ec8 100644
--- a/lib/postrunner/ActivitySummary.rb
+++ b/lib/postrunner/ActivitySummary.rb
@@ -16,6 +16,7 @@ require 'postrunner/FlexiTable'
 require 'postrunner/ViewFrame'
 require 'postrunner/HRV_Analyzer'
 require 'postrunner/Percentiles'
+require 'postrunner/HRZoneDetector'
 
 module PostRunner
 
@@ -33,9 +34,12 @@ module PostRunner
     end
 
     def to_s
-      summary.to_s + "\n" +
-      (@activity.note ? note.to_s + "\n" : '') +
-      laps.to_s
+      s = summary.to_s + "\n" +
+        (@activity.note ? note.to_s + "\n" : '') +
+        laps.to_s
+      s += hr_zones.to_s if has_hr_zones?
+
+      s
     end
 
     def to_html(doc)
@@ -45,6 +49,10 @@ module PostRunner
       ViewFrame.new('note', 'Note', width, note,
                     true).to_html(doc) if @activity.note
       ViewFrame.new('laps', 'Laps', width, laps, true).to_html(doc)
+      if has_hr_zones?
+        ViewFrame.new('hr_zones', 'Heart Rate Zones', width, hr_zones, true).
+          to_html(doc)
+      end
     end
 
     private
@@ -178,6 +186,75 @@ module PostRunner
       t
     end
 
+    def hr_zones
+      session = @fit_activity.sessions[0]
+
+      t = FlexiTable.new
+      t.head
+      t.row([ 'Zone', 'Exertion', 'Min. HR [bpm]', 'Max. HR [bpm]',
+              'Time in Zone', '% of Time in Zone' ])
+      t.set_column_attributes([
+        { :halign => :right },
+        { :halign => :left},
+        { :halign => :right },
+        { :halign => :right },
+        { :halign => :right },
+        { :halign => :right },
+      ])
+      t.body
+
+      # Calculate the total time in all the 5 relevant zones. We'll need this
+      # later as the basis for the percentage values.
+      total_secs = 0
+      each_hr_zone_with_index { |secs_in_zone, i| total_secs += secs_in_zone }
+
+      hr_mins = HRZoneDetector::detect_zones(
+        @fit_activity.records, @fit_activity.sessions[0].time_in_hr_zone[0..5])
+      each_hr_zone_with_index do |secs_in_zone, i|
+        t.cell(i)
+        t.cell([ '', 'Warm Up', 'Easy', 'Aerobic', 'Threshold', 'Maximum' ][i])
+        t.cell(hr_mins[i] || '-')
+        t.cell(i == HRZoneDetector::GARMIN_ZONES ?
+               session.max_heart_rate || '-' :
+               hr_mins[i + 1].nil? || hr_mins[i + 1] == 0 ? '-' :
+               (hr_mins[i + 1] - 1))
+        t.cell(secsToHMS(secs_in_zone))
+        t.cell('%.0f%%' % ((secs_in_zone / total_secs) * 100.0))
+
+        t.new_row
+      end
+
+      t
+    end
+
+    def has_hr_zones?
+      counted_zones = 0
+      total_time_in_zone = 0
+      each_hr_zone_with_index do |secs_in_zone, i|
+        if secs_in_zone
+          counted_zones += 1
+          total_time_in_zone += secs_in_zone
+        end
+      end
+
+      counted_zones == 5 && total_time_in_zone > 0.0
+    end
+
+    def each_hr_zone_with_index
+      return unless (zones = @fit_activity.sessions[0].time_in_hr_zone)
+
+      zones.each_with_index do |secs_in_zone, i|
+        # There seems to be a zone 0 in the FIT files that isn't displayed on
+        # the watch or Garmin Connect. Just ignore it.
+        next if i == 0
+        # There are more zones in the FIT file, but they are not displayed on
+        # the watch or on the GC.
+        break if i >= 6
+
+        yield(secs_in_zone, i)
+      end
+    end
+
     def local_value(fdr, field, format, units)
       unit = units[@unit_system]
       value = fdr.get_as(field, unit)
diff --git a/lib/postrunner/HRZoneDetector.rb b/lib/postrunner/HRZoneDetector.rb
new file mode 100644
index 0000000..2e9c003
--- /dev/null
+++ b/lib/postrunner/HRZoneDetector.rb
@@ -0,0 +1,77 @@
+#!/usr/bin/env ruby -w
+# encoding: UTF-8
+#
+# = HRZoneDetector.rb -- PostRunner - Manage the data from your Garmin sport devices.
+#
+# Copyright (c) 2017 by Chris Schlaeger <cs@taskjuggler.org>
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of version 2 of the GNU General Public License as
+# published by the Free Software Foundation.
+#
+
+module PostRunner
+
+  module HRZoneDetector
+
+    # Number of heart rate zones supported by Garmin devices.
+    GARMIN_ZONES = 5
+    # Maximum heart rate that can be stored in FIT files.
+    MAX_HR = 255
+
+    def HRZoneDetector::detect_zones(fit_records, secs_in_zones)
+      if fit_records.empty?
+        raise RuntimeError, "records must not be empty"
+      end
+      if secs_in_zones.size != GARMIN_ZONES + 1
+        raise RuntimeError, "secs_in_zones must have #{GARMIN_ZONES + 1} " +
+          "elements"
+      end
+
+      # We generate a histogram of the time spent at each integer heart rate.
+      histogram = Array.new(MAX_HR + 1, 0)
+
+      last_timestamp = nil
+      fit_records.each do |record|
+        next unless record.heart_rate
+
+        if last_timestamp
+          # We ignore all intervals that are larger than 10 seconds. This
+          # potentially conflicts with smart recording, but I can't see how a
+          # larger sampling interval can yield usable results.
+          if (delta_t = record.timestamp - last_timestamp) <= 10
+            histogram[record.heart_rate] += delta_t
+          end
+        end
+        last_timestamp = record.timestamp
+      end
+
+      # We'll process zones 5 downto 1.
+      zone = GARMIN_ZONES
+      hr_mins = Array.new(GARMIN_ZONES)
+      # Sum of time spent in current zone.
+      secs_in_current_zone = 0
+      # We process the histogramm from highest to smallest HR value. Whenever
+      # we have accumulated the provided amount of time we have found a HR
+      # zone boundary. We complete the current zone and continue with the next
+      # one.
+      MAX_HR.downto(0) do |i|
+        secs_in_current_zone += histogram[i]
+
+        if secs_in_current_zone > secs_in_zones[zone]
+          # In case we have collected more time than was specified for the
+          # zone we carry the delta over to the next zone.
+          secs_in_current_zone -= secs_in_zones[zone]
+          # puts "Zone #{zone}: #{secs_in_current_zone}  #{secs_in_zones[zone]}"
+          break if (zone -= 1) < 0
+        end
+        hr_mins[zone] = i
+      end
+
+      hr_mins
+    end
+
+  end
+
+end
+
diff --git a/lib/postrunner/PersonalRecords.rb b/lib/postrunner/PersonalRecords.rb
index 098badd..8dfcf7e 100644
--- a/lib/postrunner/PersonalRecords.rb
+++ b/lib/postrunner/PersonalRecords.rb
@@ -346,6 +346,9 @@ module PostRunner
       # meters)
       speed_records = {}
 
+      # Ignore FIT files that don't have an activity or session
+      return unless activity.fit_activity && activity.fit_activity.sessions
+
       segment_start_time = activity.fit_activity.sessions[0].start_time
       segment_start_distance = 0.0