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Former-commit-id:a02aeb236c[formerly9f19e3f712] [formerlya02aeb236c[formerly9f19e3f712] [formerly06a8b51d6d[formerly 64fa9254b946eae7e61bbc3f513b7c3696c4f54f]]] Former-commit-id:06a8b51d6dFormer-commit-id:8e80217e59[formerly3360eb6c5f] Former-commit-id:377dcd10b9
104 lines
No EOL
3.9 KiB
Python
104 lines
No EOL
3.9 KiB
Python
##
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# This software was developed and / or modified by Raytheon Company,
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# pursuant to Contract DG133W-05-CQ-1067 with the US Government.
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#
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# U.S. EXPORT CONTROLLED TECHNICAL DATA
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# This software product contains export-restricted data whose
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# export/transfer/disclosure is restricted by U.S. law. Dissemination
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# to non-U.S. persons whether in the United States or abroad requires
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# an export license or other authorization.
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#
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# Contractor Name: Raytheon Company
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# Contractor Address: 6825 Pine Street, Suite 340
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# Mail Stop B8
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# Omaha, NE 68106
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# 402.291.0100
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#
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# See the AWIPS II Master Rights File ("Master Rights File.pdf") for
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# further licensing information.
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###
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## @file CompBy.py
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from numpy import cos, sin, sqrt
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from Vector import execute as Vector
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##
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# This function is based on the comp_by.f Fortran function by J. Ramer, Jul 1 2003.
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# It returns the component of Vecs in the direction of ThGrd, normalized by the
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# magnitude of ThGrd, as a two-component vector. ThGrd is rotated by Angle before
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# the component calculation.
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#
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# comp_by.f performs different calculations based on whether Angle is supplied at all,
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# whether it is an integer, and the value of abs(Angle)/1000. This function corresponds
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# to the calculations performed in comp_by.f when Angle is an integer and abs(Angle)/1000
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# is equal to 2. Unless Angle is 0. ( see comp_by.f )
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#
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# @param Vecs: Data vector as a tuple of arrays
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# @param ThGrd: Potential temperature gradient vector as a tuple of arrays
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# @param Angle: Degrees through which to rotate first vector before
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# dotting it with the second vector. May be a scalar or array.
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# Any 1000s component is ignored for compatibility with old code;
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# otherwise, valid values fall in the range [-180..180]. Angles
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# outside the allowed range are treated as an angle of 0.
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#
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# @return: a tuple of 2 arrays representing the vector components of Vecs in the
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# direction of ThGrd, normalized by the magnitude of ThGrd.
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#
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def execute(Vecs, ThGrd, Angle=0):
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""
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# pi/180 for degrees to radians conversion
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dgtord = 0.01745329252
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Vecs_U, Vecs_V = Vecs[2], Vecs[3]
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ThGrd_U, ThGrd_V = ThGrd[2], ThGrd[3]
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if Angle != 0:
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# Strip off any 1000s from angle.
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# The second part makes sure -2090 ends up as -90 rather than 910.
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# This works with scalars or arrays, where "if angle<0:" wouldn't.
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Angle = Angle % 1000 + (Angle < 0) * -1000
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# Angle has to be in the [-180..180] range.
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# If not, convert it to zero.
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Angle = Angle - (Angle > 180) * Angle
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Angle = Angle - (Angle < -180) * Angle
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# convert angle in degrees to U and V vector components
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rotate_u = cos( dgtord * Angle )
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rotate_v = sin( dgtord * Angle )
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# find the rotated vector
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rotated_u = ThGrd_U * rotate_u + ThGrd_V * rotate_v
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rotated_v = ThGrd_V * rotate_u - ThGrd_U * rotate_v
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mag = rotated_u * rotated_u + rotated_v * rotated_v
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# we have to divide by the magnitude, so mask away any zero values
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# find the components
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zeroMag = (mag == 0)
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mag[zeroMag] = 1
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mag = (rotated_u * Vecs_U + rotated_v * Vecs_V)/mag
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mag[zeroMag] = 0
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comp = rotated_u * mag
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comp2 = rotated_v * mag
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return Vector(comp, comp2)
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else:
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# initialize to u and v from ThGrd
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rotated_u = ThGrd_U
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rotated_v = ThGrd_V
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#calculate the magnitude
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mag = rotated_u * rotated_u + rotated_v * rotated_v
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mag = sqrt(mag)
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#magical math that I don't know what it does
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zeroMag = (mag == 0)
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mag[zeroMag] = 1
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mag = (rotated_u * Vecs_U + rotated_v * Vecs_V)/mag
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mag[zeroMag] = 0
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return mag |