added return nil for calibration if no hd_intervals present

Author: Martin Hinz

app/models/calibration.rb

@@ -51,15 +51,17 @@ def calibrate
 
   # Force recalibration and update all attributes accordingly
   def recalibrate
-    return nil unless c14_age.present? && c14_error.present? && c14_curve.present?
+      return nil unless c14_age.present? && c14_error.present? && c14_curve.present?
 
     logger.info "Calibrating #{{ c14_age: c14_age, c14_error: c14_error, c14_curve: c14_curve}}"
     calibration = Calibrator::Calibration.new(c14_age, c14_error, c14_curve)
 
-    self.taq = calibration.hd_intervals.map { |i| i["begin"] }.max
-    self.tpq = calibration.hd_intervals.map { |i| i["end"] }.min
-    # TODO: terrible, but currently unused, so...
-    self.centre = self.tpq + ((self.taq - self.tpq) / 2)
+    return nil unless calibration.hd_intervals.present?
+
+      self.taq = calibration.hd_intervals.map { |i| i["begin"] }.max
+      self.tpq = calibration.hd_intervals.map { |i| i["end"] }.min
+      # TODO: terrible, but currently unused, so...
+      self.centre = self.tpq + ((self.taq - self.tpq) / 2)
 
     # Not persisted
     self.prob_dist = calibration.prob_dist