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{ RCSid $Id: rskysrc.cal,v 1.2 2009/07/14 16:16:20 greg Exp $ } |
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{ |
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Reinhart sky patch positions & solid angles |
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|
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Greg Ward June 2009 |
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Based on tregsrc.cal |
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MF constant controls patch density, and should be assigned in advance |
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Input is Rbin from 1-(144*MF^2+1) and optional x1 x2 random variables |
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Output is Dx Dy Dz theta (degree full angle of source) |
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} |
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DEGREE : PI/180; |
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x1 = .5; x2 = .5; { default rand. var. settings for midpoint } |
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alpha : 90/(MF*7 + .5); { Separation between rows in degrees } |
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{ Number of patches per row } |
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tnaz(r) : select(r, 30, 30, 24, 24, 18, 12, 6); |
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rnaz(r) : if(r-(7*MF-.5), 1, MF*tnaz(floor((r+.5)/MF) + 1)); |
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raccum(r) : if(r-.5, rnaz(r-1) + raccum(r-1), 0); |
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RowMax : 7*MF + 1; |
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Rmax : raccum(RowMax); |
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Rfindrow(r, rem) : if(rem-rnaz(r)-.5, Rfindrow(r+1, rem-rnaz(r)), r); |
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Rrow = if(Rbin-(Rmax-.5), RowMax, Rfindrow(0, Rbin)); |
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Rcol = Rbin - raccum(Rrow) - 1; |
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Razi_width = 2*PI / rnaz(Rrow); |
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RAH : alpha*DEGREE; |
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Razi = (Rcol + x2 - .5)*Razi_width; |
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Ralt = (Rrow + x1)*RAH; |
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Romega = if(Rmax-.5-Rbin, |
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Razi_width*(sin(RAH*(Rrow+1)) - sin(RAH*Rrow)), |
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2*PI*(1 - cos(RAH/2)) ); |
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cos_ralt = cos(Ralt); |
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Dx = sin(Razi)*cos_ralt; |
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Dy = cos(Razi)*cos_ralt; |
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Dz = sqrt(1 - cos_ralt*cos_ralt); |
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theta = 2/DEGREE * acos(1 - Romega/(2*PI)); |