<div>Hi Nick,<div><br></div><div>you can use rtrace's -f option to change the output format from floating point to ascii. (-faa)</div><div><br></div><div>The conversion from RGB irradiance to illuminance is:</div><div>
179 * ( 0.265*R + 0.670*G + 0.065*B ) </div><div><br></div><div>so you can use rcalc to calculate the percentage you desire like so:</div><div>rtrace ... | rcalc -e 'ill=($1*0.265+$2*0.670+$3*0.065)*179' -e '$1=ill/300'</div>
<div><font class="Apple-style-span" face="monospace"><span class="Apple-style-span" style="font-size: medium; white-space: pre;"><font class="Apple-style-span" face="arial"><span class="Apple-style-span" style="font-size: small; white-space: normal;"><br>
</span></font></span></font></div><div>Best,</div><div>Andy</div></div><div><br></div><br><div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
<div><br><div class="gmail_quote">On Wed, Mar 10, 2010 at 10:22 AM, Nick Hubof <span dir="ltr"><<a href="mailto:nhubof@gmail.com" target="_blank">nhubof@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<div><pre><span style="color:black">Hi,</span></pre><pre><span style="color:black">I am trying to do a similar process as below email, but with an illuminance plot. </span></pre><pre><span style="color:black">I would like to know the % above a lighting threshold of 300lux in an illumination grid output from radiance.</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">My office uses Ecotect to build daylight models with 2d analysis grids (.pts). After running radiance the analysis grid is populated into a .dat file that is renamed in the Ecotect Batch to a .ok file.</span></pre>
<pre><span style="color:black">The .ok file consists of illumination data by point.</span></pre><pre><span style="color:black">So when I open the .ok file in a text editor the values are in exponential form, ie.. (1.501146e+000 1.570207e+000 9.277438e-001). </span></pre>
<pre><span style="color:black">When viewed in the Ecotect grid this value is 270.316 lux. </span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black">Is there a way to have rtrace give me that percentage while the batch is running or at least convert the data from exponential form to ‘real’ values?</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">Please let me know what to add to the batch, I assume it will be at the rtrace section or after in the batch:</span></pre><pre><span style="color:black">rtrace </span><span style="font-size:14.0pt;color:black">…</span><span style="font-size:7.0pt;color:black">rendering settings</span><span style="font-size:14.0pt;color:black">…</span><span style="color:black"> gridtest.oct < gridtest.pts > gridtest.dat </span></pre>
<pre><span style="color:black">@RENAME gridtest3.dat gridtest3.ok </span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black">Thanks,</span></pre><pre><span style="color:black">Nick</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black"> </span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">From Greg Ward (<span><i>Mon Oct 20 10:12:17 PDT 2008)_</i></span></span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black">And here is one of the many possible standard Radiance tools ways:</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">pvalue -h -H -o -b -df input.pic | rcalc -if -of -e '$1=1;$2=if(179* </span></pre><pre><span style="color:black">$1-THRESHOLD,1,0)' | total -if2</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">You need to set THRESHOLD to the desired luminance value (in cd/ </span></pre><pre><span style="color:black">m^2). This will give you two numbers, the ratio of which is the </span></pre>
<pre><span style="color:black">percentage you seek. If you want to do it all on the command line, </span></pre><pre><span style="color:black">you can add:</span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black"> | rcalc -e '$1=100*$2/$1'</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">to the end of the pipe.</span></pre><pre><span style="color:black"> </span></pre><pre><span style="color:black">Best,</span></pre><pre><span style="color:black">-Greg</span></pre>
<pre><span style="color:black"> </span></pre><pre><span style="color:black">><i> From: "Marija Velickovic" <<a href="http://www.radiance-online.org/mailman/listinfo/radiance-general" target="_blank">maricanis at gmail.com</a>></i></span></pre>
<pre><span style="color:black">><i> Date: October 20, 2008 3:42:28 AM PDT</i></span></pre><pre><span style="color:black">><i> </i></span></pre><pre><span style="color:black">><i> Hi,</i></span></pre><pre><span style="color:black">><i> </i></span></pre>
<pre><span style="color:black">><i> I suppose you can use some of standard Radiance tools for that, but </i></span></pre><pre><span style="color:black">><i> here is another way we use.</i></span></pre><pre><span style="color:black">><i> </i></span></pre>
<pre><span style="color:black">><i> In Raddisplay <a href="http://deluminaelab.com/en/raddisplay_details.html" target="_blank">http://deluminaelab.com/en/raddisplay_details.html</a> </i></span></pre><pre><span style="color:black">><i> program you can create falsecolor image from your original radiance </i></span></pre>
<pre><span style="color:black">><i> image. If you define false color palette with 2 colors - one has </i></span></pre><pre><span style="color:black">><i> value 0 and another value you want to use as a threshold, and open </i></span></pre>
<pre><span style="color:black">><i> Statistiques dialog, you'll have percent for each color in the </i></span></pre><pre><span style="color:black">><i> tablle. You can also define the palette with more colors, for </i></span></pre>
<pre><span style="color:black">><i> various threshold values.</i></span></pre><pre><span style="color:black">><i> </i></span></pre><pre><span style="color:black">><i> Hope this helps,</i></span></pre><pre><span style="color:black">><i> Marija</i></span></pre>
<pre><span style="color:black">><i> De Luminae.</i></span></pre><pre><span style="color:black">><i> </i></span></pre><pre><span style="color:black">><i> 2008/10/20 Galen Burrell <<a href="http://www.radiance-online.org/mailman/listinfo/radiance-general" target="_blank">galenburrell at yahoo.com</a>></i></span></pre>
<pre><span style="color:black">><i> Hi All,</i></span></pre><pre><span style="color:black">><i> I have a radiance .pic with lux values calculated using rpict -i. </i></span></pre><pre><span style="color:black">><i> Is there a way to calculate the percentage of the pixels that are </i></span></pre>
<pre><span style="color:black">><i> at or above a specified value?</i></span></pre><pre><span style="color:black">><i> Thanks,</i></span></pre><pre><span style="color:black">><i> Galen</i></span></pre><pre><span style="color:black">> </span></pre>
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