55 lines
No EOL
1.7 KiB
Python
55 lines
No EOL
1.7 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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from numpy import sqrt
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from numpy import ndarray
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from numpy import float32
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##
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# Routine to calculate sweat index from the total totals,
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# 850 dewpoint, and wind components at 850 and 500.
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#
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# @param tt: Total Totals
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# @param td8: 850mb dewpoint (K)
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# @param u8: 850mb u-component (K)
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# @param v8: 850mb v-component (K)
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# @param u5: 500mb u-component (K)
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# @param v5: 500mb v-component (K)
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# @return: Sweat Index
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def execute(tt, td8, u8, v8, u5, v5):
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s8 = sqrt(u8*u8+v8*v8)
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s5 = sqrt(u5*u5+v5*v5)
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s = s8*s5
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z_mask = s == 0
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nz_mask = s != 0
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sdir = ndarray(tt.shape, float32)
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sdir[z_mask] = 0
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sdir[nz_mask] = (u5[nz_mask]*v8[nz_mask]-v5[nz_mask]*u8[nz_mask])/s[nz_mask]
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tt49= ndarray(tt.shape, float32)
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tt49_mask = tt>=49
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tt49[tt<49] = 0
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tt49[tt49_mask] = tt[tt49_mask]-49.0
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result = 12*(td8-273.15)
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result += 20*tt49
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result += 2*1.944*s8
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result += s5*1.944
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result += 125*(sdir+0.2)
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return result |