ide into 80 branches, and 80 outputs of explode and 80 dispatches - its my nightmare. Is there any way to do this with parametric Number of brunches? …
exact formula is inside /lib/skybright.cal if this can help you to find the name.
{ RCSid: $Id$ } { Sky brightness function for sunny and cloudy skies.
Additional arguments required for calculation of skybright:
A1 - 1 for CIE clear, 2 for CIE overcast, 3 for uniform, 4 for CIE intermediate A2 - zenith brightness A3 - ground plane brightness A4 - normalization factor based on sun direction A5,A6,A7 - sun direction }
cosgamma = Dx*A5 + Dy*A6 + Dz*A7;
gamma = Acos(cosgamma); { angle from sun to this point in sky }
zt = Acos(A7); { angle from zenith to sun }
eta = Acos(Dz); { angle from zenith to this point in sky }
wmean(a, x, b, y) : (a*x + b*y) / (a + b);
skybr = wmean((Dz+1.01)^10, select(A1, sunnysky, cloudysky, unifsky, intersky), (Dz+1.01)^-10, A3);
sunnysky = A2 * (.91 + 10*exp(-3*gamma) + .45*cosgamma*cosgamma) * if( Dz - .01, 1.0 - exp(-.32/Dz), 1.0) / A4;
cloudysky = A2 * (1 + 2*Dz)/3;
unifsky = A2;
intersky = A2 * ( (1.35*sin(5.631-3.59*eta)+3.12)*sin(4.396-2.6*zt) + 6.37 - eta ) / 2.326 * exp(gamma*-.563*((2.629-eta)*(1.562-zt)+.812)) / A4;
…
rkup) as below:
float coeff_perez [] is from Perez's paper in solar energy vol. 50, No.3. pp235-245, 1993.
i would like to adjust A3, A4, A5, A6 and A7 using measurement irradiance data over a whole year for every minute or hour, and update these coefficients under the file perezlum.cal. It means i may need to re-compile gendaylit.exe, which i have no idea how to do it.
i found radiance has another version on gendaymtx.c v2.13. it includes static const double PerezCoeff[8][20]. I am wondering which version of gendaymtx does ladybug GenCumulativeSkyMtx use.
Thanks for your suggestions on honeybee plugin. I will take a look and see how.
Cheers,
Le
…