From 362ee0a2f44bcef67b2c6180b5443a74e89f73ac Mon Sep 17 00:00:00 2001
From: XANTRONIX Industrial <xan@xantronix.com>
Date: Sun, 9 Mar 2025 16:14:20 -0400
Subject: [PATCH] Do not compute lapse on first height
---
lib/xmet/thermo.py | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)
diff --git a/lib/xmet/thermo.py b/lib/xmet/thermo.py
index 193e068..1c17ec0 100644
--- a/lib/xmet/thermo.py
+++ b/lib/xmet/thermo.py
@@ -123,19 +123,17 @@ def loft_parcel(start_temp: float,
while pressure >= PRESSURE_MIN:
height = pressure_height(pressure)
- if height_last is None:
- height_last = height
+ if height_last is not None:
+ try:
+ rate = lapse_rate(temp, pressure)
+ except OverflowError:
+ break
- try:
- rate = lapse_rate(temp, pressure)
- except OverflowError:
- break
+ height_delta = height - height_last
- temp = lapse(temp, height - height_last, rate)
+ temp = lapse(temp, height_delta, rate)
- yield temp, pressure
-
- height_last = height
+ yield temp, pressure
if pressure == PRESSURE_MIN:
break
@@ -144,6 +142,8 @@ def loft_parcel(start_temp: float,
else:
pressure -= step
+ height_last = height
+
def follow_dry_adiabat(temp: float, pressure: float) -> Series:
"""
Follow a dry adiabat starting at a given temp and pressure level, returning