The writeldt function saves a given luminous distribution curve as EULUMDAT file.
Note: EULUMDAT files are usually normalized at 1000 lm luminous flux, the luminous intensity should therefore be given in cd/klm.
I_{\textrm{norm}}\left(\gamma\right) = I\left(\gamma\right)\cdot \frac{1000}{\Phi_{\textrm{luminaire}}}Usage:
writeldt(file,ldt,'normalize')
Where:
Parameter | Description |
file | Specifies path and filename. |
ldt | Is the ldt struct containing the EULUMDAT file information: ldt.name – gives the luminiare name information ldt.header – contains the file header information ldt.anglesC – contains the C angles ldt.anglesG – contains the angles ldt.I – contains the corresponding luminous intensities |
'normalize' (optional) | Will perform the normalization to cd/klm before saving the EULUMDAT file. |
Examples
Read, adjust, save and plot a ldt file:
% Import Lambert ldt ldt = readldt('lambert.ldt'); % Adjust luminous intensity distribution ldt.I = ldt.I.*cosd(ldt.anglesG); ldt.name = 'luminaire'; % Save in new .ldt file writeldt('newldt.ldt',ldt,'normalize') % read new .ldt file and plot luminous intensity distribution newldt = readldt('newldt.ldt'); plot2dldc(newldt)
Result:
References
Thinking Photometrically Part II. 2011, (LIGHTFAIR 2001 Pre-Conference Workshop).
EULUMDAT – ein Leuchtendatenformat für den europäischen Beleuchtungplaner. In: 9. Gemeinschaftstagung der Lichttechnischen Gesellschaften Deutschlands, der Niederlande, Österreichs und Schweiz, pp. 641–644, Nederlandse Stichting voor Verlichtingskunde, 1990.