Implement SkewT.draw_series()

Implement SkewT.draw_series() to plot a Series object

lib/xmet/skew_t.py

@@ -3,11 +3,13 @@ import cairo
 
 from typing    import Callable
 
-from xmet.sounding import Sounding
+from xmet.sounding import Sounding, SoundingParameters
 from xmet.thermo   import loft_parcel, moist_lapse_rate, \
                           LAPSE_RATE_DRY, PRESSURE_MAX, PRESSURE_MIN, \
                           PRESSURE_STEP
 
+from xmet.series import Series
+
 PRESSURE_LOG_MAX   = math.log(PRESSURE_MAX)
 PRESSURE_LOG_MIN   = math.log(PRESSURE_MIN)
 PRESSURE_LOG_RANGE = PRESSURE_LOG_MAX - PRESSURE_LOG_MIN
@@ -140,6 +142,26 @@ class SkewTGraph():
 
         cr.restore()
 
+    def draw_series(self,
+                    cr: cairo.Context,
+                    x: float,
+                    y: float,
+                    series: Series):
+        first = True
+
+        for pressure in series:
+            temp = series[pressure]
+
+            sx, sy = self.sample_to_screen(temp, pressure)
+
+            if first:
+                cr.move_to(x + sx, y + sy)
+                first = False
+            else:
+                cr.line_to(x + sx, y + sy)
+
+        cr.stroke()
+
     def draw_sounding(self,
                      cr: cairo.Context,
                      x: float,