From c0ed20cce50b02d2b21fdf8e253e6f8f5cf69591 Mon Sep 17 00:00:00 2001
From: XANTRONIX Industrial <xan@xantronix.com>
Date: Wed, 5 Mar 2025 16:13:50 -0500
Subject: [PATCH] Reimplement draw_adiabat() with loft_parcel()
---
lib/xmet/skew_t.py | 44 +++++++++-----------------------------------
1 file changed, 9 insertions(+), 35 deletions(-)
diff --git a/lib/xmet/skew_t.py b/lib/xmet/skew_t.py
index 6dc0e5e..f30b878 100644
--- a/lib/xmet/skew_t.py
+++ b/lib/xmet/skew_t.py
@@ -4,12 +4,9 @@ import cairo
from typing import Callable
from xmet.sounding import Sounding
-from xmet.thermo import pressure_height, lapse, moist_lapse_rate, \
- LAPSE_RATE_DRY
-
-PRESSURE_MAX = 1050 # millibar
-PRESSURE_MIN = 100
-PRESSURE_STEP = 50
+from xmet.thermo import pressure_height, loft_parcel, moist_lapse_rate, \
+ LAPSE_RATE_DRY, PRESSURE_MAX, PRESSURE_MIN, \
+ PRESSURE_STEP
PRESSURE_LOG_MAX = math.log(PRESSURE_MAX)
PRESSURE_LOG_MIN = math.log(PRESSURE_MIN)
@@ -107,26 +104,11 @@ class SkewTGraph():
start_temp: float,
start_pressure: float,
lapse_rate: Callable):
- start_height = pressure_height(start_pressure)
- sx_last = None
- sy_last = None
- height_last = None
+ sx_last = None
+ sy_last = None
- temp = start_temp
- pressure = start_pressure
-
- while pressure >= PRESSURE_MIN:
- height = pressure_height(pressure)
-
- if height_last is None:
- height_last = height
-
- try:
- rate = lapse_rate(temp, temp, pressure)
- except OverflowError:
- break
-
- temp = lapse(temp, height - height_last, rate)
+ for level in loft_parcel(start_temp, start_pressure, lapse_rate):
+ temp, pressure = level
sx, sy = self.sample_to_screen(temp, pressure)
@@ -135,16 +117,8 @@ class SkewTGraph():
cr.line_to(x + sx_last, y + sy_last)
cr.stroke()
- sx_last = sx
- sy_last = sy
- height_last = height
-
- if pressure == PRESSURE_MIN:
- break
- elif pressure - 10.0 < PRESSURE_MIN:
- pressure = PRESSURE_MIN
- else:
- pressure -= 10.0
+ sx_last = sx
+ sy_last = sy
def draw_adiabats(self,
cr: cairo.Context,