From cae66a64e71428bf202e3411cf016346e75a9211 Mon Sep 17 00:00:00 2001
From: David Hoese <davidh@ssec.wisc.edu>
Date: Wed, 30 Sep 2009 21:18:26 +0000
Subject: [PATCH] added a few functions and array_convert function
---
metobs/data/__init__.py | 77 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 75 insertions(+), 2 deletions(-)
diff --git a/metobs/data/__init__.py b/metobs/data/__init__.py
index 3a71b29..a42806e 100644
--- a/metobs/data/__init__.py
+++ b/metobs/data/__init__.py
@@ -168,7 +168,7 @@ def dewpoint(tempC, relhum):
def relhum(airTempK, dewpointTempK):
"""
- Algorithm from derived by David Hoese from the above
+ Algorithm derived by David Hoese from the above
dewpoint(tempC, relhum) function, both parameters are in Kelvin units.
:param airTempK: air temperature in Kelvin
@@ -242,8 +242,15 @@ def linearConvert(data, factor=1, offset=0):
return data * float(factor) + offset
def mm2in(val):
+ """Convert millimeters to inches.
+ """
return linearConvert(val, 0.0393700787)
+def in2mm(val):
+ """Convert inches to millimeters.
+ """
+ return linearConvert(val, 1/0.0393700787)
+
def c2f (val):
"""Degrees celsius to fahrenheit.
@@ -254,6 +261,16 @@ def c2f (val):
"""
return linearConvert(val, (9/5.), 32)
+def f2c(val):
+ """Degrees fahrenheit to celsius.
+
+ >>> f2c(32)
+ 0.0
+ >>> f2c(212)
+ 100.0
+ """
+ return linearConvert(val-32, (5/9.), 0)
+
def mps2mph (val):
"""Speed in meters per second to miles per hour.
"""
@@ -264,6 +281,11 @@ def mps2knots (val):
"""
return linearConvert(val, 1.9438445)
+def knots2mps(val):
+ """Speed in knots to meters per second.
+ """
+ return linearConvert(val, 1/1.9438445)
+
def altimeter(p, alt):
"""Compute altimeter from pressure and altitude.
@@ -308,7 +330,58 @@ def dir2txt (val):
if val >= i and val < (i + 22.5):
return dir
i += 22.5
-
+
+def array_convert(arr, sunits, cunits):
+ """Converts the data in array arr from sunits to cunits.
+
+ :param arr: Array to be converted
+ :type arr: ndarray
+ :param sunits: Starting Units = 'C', 'F', 'm/s', 'knots', 'hpa', 'deg', 'in', 'mm', 'w/m2'
+ :type sunits: string
+ :param cunits: Convert to Units = Same choices as sunits
+ :type cunits: string
+ """
+ if sunits == cunits: return arr
+ if type(arr) != ndarray: raise ValueError("Array must be of type numpy.ndarray")
+ shape = arr.shape
+ a = arr.flatten()
+ if sunits == 'c':
+ if cunits == 'f':
+ for i in range(len(a)):
+ a[i] = c2f(a[i])
+ return a.reshape(shape)
+ elif sunits == 'f':
+ if cunits == 'c':
+ for i in range(len(a)):
+ a[i] = f2c(a[i])
+ return a.reshape(shape)
+ elif sunits == 'm/s':
+ if cunits == 'knots':
+ for i in range(len(a)):
+ a[i] = mps2knots(a[i])
+ return a.reshape(shape)
+ elif sunits == 'knots':
+ if cunits == 'm/s':
+ for i in range(len(a)):
+ a[i] = knots2mps(a[i])
+ return a.reshape(shape)
+ elif sunits == 'hpa':
+ return a.reshape(a)
+ elif sunits == 'deg':
+ return a.reshape(a)
+ elif sunits == 'in':
+ if cunits == 'mm':
+ for i in range(len(a)):
+ a[i] = in2mm(a[i])
+ return a.reshape(shape)
+ elif sunits == 'mm':
+ if cunits == 'in':
+ for i in range(len(a)):
+ a[i] = mm2in(a[i])
+ return a.reshape(shape)
+ elif sunits == 'w/m2':
+ return a.reshape(a)
+ raise ValueError("sunits or cunits was not an acceptable unit")
if __name__ == '__main__':
import doctest
doctest.testmod()
--
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