add model training

internal/db/series.go

@@ -15,15 +15,17 @@ type ObservationPoint struct {
 	TempC       *float64  `json:"temp_c,omitempty"`
 	RH          *float64  `json:"rh,omitempty"`
 	PressureHPA *float64  `json:"pressure_hpa,omitempty"`
-	WindMS      *float64  `json:"wind_m_s,omitempty"`
-	WindGustMS  *float64  `json:"wind_gust_m_s,omitempty"`
-	WindDirDeg  *float64  `json:"wind_dir_deg,omitempty"`
-	UVI         *float64  `json:"uvi,omitempty"`
-	LightLux    *float64  `json:"light_lux,omitempty"`
-	BatteryMV   *float64  `json:"battery_mv,omitempty"`
-	SupercapV   *float64  `json:"supercap_v,omitempty"`
-	RainMM      *float64  `json:"rain_mm,omitempty"`
-	RainStart   *int64    `json:"rain_start,omitempty"`
+	// PressureTrend1h is the change in pressure over the last hour (hPa).
+	PressureTrend1h *float64 `json:"pressure_trend_1h,omitempty"`
+	WindMS          *float64 `json:"wind_m_s,omitempty"`
+	WindGustMS      *float64 `json:"wind_gust_m_s,omitempty"`
+	WindDirDeg      *float64 `json:"wind_dir_deg,omitempty"`
+	UVI             *float64 `json:"uvi,omitempty"`
+	LightLux        *float64 `json:"light_lux,omitempty"`
+	BatteryMV       *float64 `json:"battery_mv,omitempty"`
+	SupercapV       *float64 `json:"supercap_v,omitempty"`
+	RainMM          *float64 `json:"rain_mm,omitempty"`
+	RainStart       *int64   `json:"rain_start,omitempty"`
 }
 
 type ForecastPoint struct {
@@ -147,6 +149,23 @@ func (d *DB) ObservationSeries(ctx context.Context, site, bucket string, start,
 		return nil, rows.Err()
 	}
 
+	indexByTime := make(map[time.Time]int, len(points))
+	for i := range points {
+		indexByTime[points[i].TS] = i
+	}
+	for i := range points {
+		if points[i].PressureHPA == nil {
+			continue
+		}
+		target := points[i].TS.Add(-1 * time.Hour)
+		j, ok := indexByTime[target]
+		if !ok || points[j].PressureHPA == nil {
+			continue
+		}
+		trend := *points[i].PressureHPA - *points[j].PressureHPA
+		points[i].PressureTrend1h = &trend
+	}
+
 	return points, nil
 }