[Radiance-general] calculating CRI and CCT

[Christian Humann]

Dear all,

Has anyone had the need and therefore figured out how to calculate CRI at a specific point within a daylit scene using Radiance?  Specifically I'm thinking of John Mardaljevic's paper on electrochromic glass where he used a spectrometer to get CRI of different combinations of glass tint.

I was thinking of using different HDR sky capture photos within gendaylit to simulate different sky conditions, and therefore was wondering also if there is a way to calculate CCT and SPD of these sky images with and without sun.

I'm in the early stages of scratching my head around all this, and as such may be barking up the wrong tree.  

Thanks.

Chris

> On Feb 23, 2015, at 1:27 PM, Greg Ward <gregoryjward at gmail.com> wrote:
> 
> Hi Reiner,
> 
> It's true that this behavior is not properly documented.  If you can suggest a logical place where you would expect to find it, perhaps I can add the appropriate text.
> 
> Since rfluxmtx and rmtxop are new, the documentation is not as complete as it should be.
> 
> Cheers,
> -Greg
> 
>> From: Reinier Zeldenrust <reinier.zeldenrust at atelierten.com>
>> Subject: Re: [Radiance-general] Radiance-general Digest, Vol 132, Issue 12
>> Date: February 23, 2015 9:59:29 AM PST
>> 
>> Hi Mostapha, 
>> 
>> Thank you - helpful! Where is this behaviour documented? I could not find it in the rfluxmtx or rcontrib manpages.
>> 
>> Best,
>> 
>> Reinier Zeldenrust
>> Environmental Designer
>> Atelier Ten
>> Environmental Design Consultants + Building Services Engineers
>> 
>> CIBSE Building Services Consultancy of the Year 2011
>> UK-GBC Sustainability Consultant of the Year 2009
>> 
>> 
>> Message: 1
>> Date: Fri, 20 Feb 2015 11:59:55 +0000
>> From: Reinier Zeldenrust <reinier.zeldenrust at atelierten.com>
>> To: "radiance-general at radiance-online.org"
>>    <radiance-general at radiance-online.org>
>>    
>> Content-Type: text/plain; charset="us-ascii"
>> 
>> Hi all, 
>> 
>> I am following the latest approach to the three-phase method as described in Andy McNeil's 2014 Radiance Workshop Presentation, but when I generate view matrices my output is botched. 
>> With this command (I realise this is low accuracy, but for the moment I'm mainly testing workflow) :
>>    rfluxmtx -ab 4 -ad 5000 < ChEast.pts - windows_pts/window_00.rad material.rad ChEast.rad > viewpts_00.mtx the header in the viewmatrix is as follows:
>>    #?RADIANCE
>>    oconv -f material.rad ChEast.rad windows_pts/window_01.rad
>>    rcontrib -fo+ -ab 4 -ad 5000 -faa -c 1 -f klems_full.cal -bn Nkbins -b kbin(0.525501,0.0136168,-0.850684,0,0,1) -m M-nor
>>    SOFTWARE= RADIANCE 4.3a lastmod  by nrel_nt
>>    gugliel on rgugliel-W7-VM
>>    CAPDATE= 2015:02:19 12:21:14
>>    GMT= 2015:02:19 12:21:14
>>    NCOMP=3
>>    NCOLS=145
>>    FORMAT=ascii
>> 
>> When I try to do any matrix multiplication to get the three-phase result, I get problems with RMTXOP or dctimestep, which complain they can't load the matrix. If I add the line NROWS=81 (number of sensor points) manually in the header, I do get results. But I'm trying to run the simulation for a lot of windows so adding this line each time manually or with a script is a bit painful. Am I doing something wrong or is this a bug?
>> 
>> Additionally, when I try to run dctimestep in annual mode, using the following command:
>>    dctimestep -n 8760 viewpts_00.mtx grate.xml daylight_00.mtx annual.smx > test.dat I get:
>>    'fatal - unexpected EOF reading annual.smx' 
>> even though my annual.smx has 146 rows (for all 146 Tregenza daylight patches) and 8760 columns. 
>> 
>> Any idea what is going wrong here?
>> 
>> Many thanks,
>> Reinier
>> 
>> 
>> Reinier Zeldenrust
>> Environmental Designer
>> Atelier Ten
>> Environmental Design Consultants + Building Services Engineers
>> 
>> ------------------------------
>> 
>> Message: 2
>> Date: Fri, 20 Feb 2015 09:48:26 -0500
>> From: Mostapha Sadeghipour <sadeghipour at gmail.com>
>> To: Radiance general discussion <radiance-general at radiance-online.org>
>> 
>> Hi Reinier,
>> 
>> You need to use the -y option to specify the number of rows in your rfluxmtx run so you don't need to do it manually.
>> 
>> Cheers,
>> Mostapha
> 
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