frudawski

# plotpolarE

The plotpolarE function calculates the resulting horizontal and vertical illuminances for a given Tregenza luminance distribution with 145 patches and plots the resulting illuminance distribution. The Tregenza hemisphere is assumed to have 100% coverage as in figure 1 in contrast to the original Tregenza model.

Usage:

[Eh,Ev] = polardataE(L,vdir)

Where:

Examples

Horizontal and vertical illuminance (N,E,S,W) for CIE sky 12 with \alpha_S=180° and \gamma_S = 40°:

L = ciesky(12,180,40,'Eh',1e4);
[Eh,Ev] = plotpolarE(L,[0 90 180 270])

Result:

Eh = 10000.0
Ev =

3.5917e+03
6.1367e+03
1.0112e+04
4.4096e+03

Reference

Peter Roy Tregenza: Subdivision of the sky hemisphere for luminance measurements. In: Lighting Research and Technology, vol. 19, no. 1, pp. 13-14, 1987, (DOI: 10.1177/096032718701900103).