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.\" RCSid $Id$ |
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.TH GENDAYMTX 1 01/19/13 RADIANCE |
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.SH NAME |
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gendaymtx - generate an annual Perez sky matrix from a weather tape |
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.SH SYNOPSIS |
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.B gendaymtx |
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[ |
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.B "\-v" |
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][ |
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.B "\-d|\-s" |
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][ |
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.B "\-m N" |
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][ |
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.B "\-g r g b" |
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][ |
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.B "\-c r g b" |
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][ |
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.B "-o{f|d}" |
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] |
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[ |
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.B "tape.wea" |
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] |
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.SH DESCRIPTION |
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.I Gendaymtx |
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takes a weather tape as input and produces a matrix of sky patch |
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values using the Perez all-weather model. |
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The weather tape is assumed to be in the simple ASCII format understood |
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by DAYSIM, which contains a short header with the site parameters followed |
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by the month, day, standard time, direct normal and diffuse horizontal |
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irradiance values, one time step per line. |
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Each time step line is used to compute a column in the output matrix, |
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where rows correspond to sky patch positions, starting with 0 for |
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the ground and continuing to 145 for the zenith using the default |
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.I "\-m 1" |
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parameter setting. |
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.PP |
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Increasing the |
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.I \-m |
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parameter, typically by factors of two, yields a higher resolution |
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sky using the Reinhart patch subdivision. |
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For example, setting |
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.I "\-m 4" |
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yields a sky with 2305 patches plus one patch for the ground. |
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Each matrix entry is in fact three values, corresponding to |
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red green and blue radiance channels (watts/sr/meter^2). |
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Thus, an hourly weather tape for an entire year would |
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yield 8760x3 (26280) values per output line (row). |
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.PP |
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The |
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.I \-c |
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option may be used to specify a color for the sky. |
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The gray value should equal 1 for proper energy balance |
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The default sky color is |
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.I "\-c 0.960 1.004 1.118". |
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Similarly, the |
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.I \-g |
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option may be used to specify a ground color. |
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The default value is |
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.I "\-g 0.2 0.2 0.2" |
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corresponding to a 20% gray. |
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.PP |
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The |
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.I \-d |
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option may be used to produce a sun-only matrix, with no sky contributions. |
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Alternatively, the |
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.I \-s |
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option may be used to exclude any direct solar component from the output. |
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.PP |
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The |
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.I \-of |
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or |
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.I \-od |
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option may be used to specify binary float or double output, respectively. |
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This is much faster to write and to read, and is therefore preferred on |
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systems that support it. |
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(MS Windows is not one of them.)\0 |
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Finally, the |
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.I \-v |
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option will enable verbose reporting, which is mostly useful for |
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finding out how many time steps are actually in the weather tape. |
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.SH EXAMPLES |
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Produce an uncolored Tregenza sky matrix without solar direct: |
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.IP "" .2i |
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gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx |
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.PP |
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Produce an hourly, annual Reinhart sky matrix |
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with 2306 patches including solar contributions |
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and send float output to |
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.I dctimestep(1) |
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to compute a sensor value matrix: |
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.IP "" .2i |
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gendaymtx -m 4 -of VancouverBC.wea | dctimestep -if -n 8760 DCoef.mtx > res.dat |
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.SH AUTHORS |
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Ian Ashdown wrote most of the code, |
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based on Jean-Jacques Delaunay's original gendaylit(1) implementation. |
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Greg Ward wrote the final parameter parsing and weather tape conversion. |
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.SH "SEE ALSO" |
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dctimestep(1), genBSDF(1), gendaylit(1), genskyvec(1), rcontrib(1) |
