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How to match Illuminance map data from Radiance/Openstudio with .ill data

asked 2017-02-20 15:22:12 -0600

BORM gravatar image

updated 2017-03-07 16:26:28 -0600

Hi everyone,

I'm actually working with Radiance on OpenStudio to simulate daylighting. The model was made on SketchUp.

The illuminance map was made from 3 x 3 grid points (3x3 = 9 points of data). In the .ill file I got 9 data of daylighting per hour (Lux).

Here is my question: How to match Illuminance map with .ill data? Exemple: Do the data lead from the top left to the bottom right? How to interpret the data in the .ill file?

My objective is to know where the data are located on the illuminance map.

Thank you for your help,

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answered 2017-02-21 11:00:24 -0600

There is a file called in the numeric directory of the radiance measure's run dir; this is a concatenated list of all the illuminance maps found in the OSM, translated to Radiance rcalc inputs. These inputs take the form x y z vx vy vz, e.g.:

0.305 0.305 0.762 0.000 0.000 1.000

In the example above, there is an illuminance map point defined at 0.305 meters in the x and y from model origin (world coordinates), 0.762 meters off the floor, and the calc point is looking 'up' (view vector is 0 0 1). is the input to Radiance, so the output file (output/merged_space.ill) relates to this input file. IOW, each row in the .ill file after the header is an 8,760 csv list of daylight illuminance for each point found in numeric/, in the same order. You could visualize the data spatially with any number of tools (R and friends, D3 or whatever Javascript flavor of the week is). We have done this internally with R for checking the integrity of the output of the Radiance measure, simply mapping the x y z from to the value(s) found in the corresponding rows in merged_space.ill. Make sense?

By the way, if you have shading controls on your model and save the individual window group data you can visualize each window group's contribution to the whole building for each shade condition. This is awesome and cool. Again, a visualization interface would be somewhat easy to develop and would pay huge dividends. This is an exercise for the user, as my friend @GregWard has said before. =)

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Hi, thank you for your answer.

When I import output/merged_space.ill file in Excel, I got this:

0.00E+00    1.30E+03    3.90E+03 ... (Header)
0.00E+00    1.33E+03    3.96E+03 ...
0.00E+00    1.29E+03    4.18E+03...
0.00E+00    8.45E+02    2.48E+03 ...
0.00E+00    9.37E+02    2.25E+03 ...
0.00E+00    1.01E+03    3.17E+03 ...
0.00E+00    6.25E+02    1.98E+03 ...
0.00E+00    7.02E+02    2.09E+03 ...
0.00E+00    9.00E+02    2.67E+03...
0.00E+00    1.02E+03    3.64E+03 ...

Which data the header means? Did the first column starts on 01/01/1:00:00 ?

Thank you for your help again.

BORM gravatar image BORM  ( 2017-02-28 16:41:25 -0600 )edit

Each column is for an hour and there are 8760 columns for 8760 hours however the first column is actually the results for 1 1 0.500. The wea file and so the sky is created for between the hours. Check the in.wea file under radiance\wx folder to see the values for each hour.

Mostapha Roudsari gravatar image Mostapha Roudsari  ( 2017-03-09 17:25:04 -0600 )edit

Thank you @Mostapha Roudsari.

But, I got one more question. In the example above, There are 10 lines but the the grid is 9 points(So, 9 lines). Did the first line is related to daylight sensor or something else?

BORM gravatar image BORM  ( 2017-03-10 09:07:27 -0600 )edit

The number of lines and the number of points should be the same. In the example that I have sensors are written to separate files and are calculated separately.

Mostapha Roudsari gravatar image Mostapha Roudsari  ( 2017-03-10 10:13:13 -0600 )edit

Thank you for your answer!

BORM gravatar image BORM  ( 2017-03-10 11:21:34 -0600 )edit

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Asked: 2017-02-20 15:22:12 -0600

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Last updated: Mar 07 '17