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;
…
nt to multiply the number of items in the list A, so at the end I will end up with the same number of elements in each lists.
e.g. (for branch 1 in list A I want to have two times the same curve, and the same for the branch 2 and so on )
List A (Data with 88 branches)
{0} N=1
{1} N=1
{2} N=1
{3} N=1...
List B (Data with 88 branches)
{0} N=1
{1} N=2
{2} N=2
{3} N=1...
NEW List A (Data with 88 branches)
{0} N=1
{1} N=2
{2} N=2
{3} N=1...
Any suggestions about how to do this?
Thank you,
Martha
…
hope it will do the job (maybe its not the cleanest way, but it works for me sometimes. Depending on the ending of the lists you should wrap or not the shift component.
Good luck…
Added by Pep Tornabell at 2:05am on November 19, 2009
Here's the puzzle of the day for the brave (Big Prize: ONE secondhand sardine can, no kidding in pure 15W/50 mineral oil).
Explain this mismatch (85 VS 75):
Moral: life sucks
blinds be (B1,B2..B5). Then the geometry for the five iterations will be ((A+B1), (A+B2)...(A+B5)).
And assume that you are measuring illuminance at four points inside the room (x1,x2,x3,x4) and one point outside the room(y1).
The way Daysim works ( and should work as per the best of my understanding) is that for each setting of the blind (ie. B1,B2,..B5), a separate value of (x1,x2,x3,x4) gets calculated through the Daylight Coefficient Method. So let's say you have illuminance thresholds of (p,q,r,s,t) corresponding to (B1,B2,..B5). What the shade-control algorithm does is that it compares the illuminance at y1 with your threshold of (p,q,..t) and then chooses a value of (x1,x,2,x3,x4) on basis of that. So, when we repeat this process for (365x24=)8760 hours , we end up with a value of a shade setting for each hour which was set on basis of your threshold illuminance values.
I would have gladly answered your question on HB itself, however, I usually work with Daysim directly through commandline.
(BTW, if you are interested in reading more about Daysim google Christoph Reinhart's dissertation on the subject, along with some papers by Zack Rogers).…