NASA weight filter

     if ( $last_weight ) {
        $delta_weight = $weight - $last_weight;
        $delta_time = ($time - $last_time)/3600;
        $delta_rain =  $rain - $last_wx_rain;
        
        if ($delta_time) { $dwdt = $delta_weight/$delta_time; }
        
                                                                # Begin NASA manipulation change filter
        if ( ($weight_filter eq "NASA") 
          && (abs $dwdt > $max_dwdt_lbs_per_hour)               # if the change in weight exceeds the threshold
          && ($start_zero_weight == 0)                          # and the data is not starting off with zeros
          && ($quality != 6) )                                  # and this record is not flagged as a swarm (Quality 6)
           {                                                    # then don't count the change as daily change,
           $manipulation_change +=  $delta_weight;              # count it as manipulation change
           }
        else
           {
           $daily_change += $delta_weight;                      # otherwise, count it as part of the daily change
           }
        }
        else {                                                  #first time through
             $daily_change = $weight;
             $first_graph_date = $row[0];
             $last_wx_rain = $row[10];
             $delta_rain = 0;
        }
        $last_weight = $weight;
        $weight = $daily_change; 
                                                                 # end NASA filter
        $last_temperature = $temperature;
        $last_time = $time;