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root/radiance/ray/doc/man/man1/gendaymtx.1
Revision: 1.1
Committed: Sun Jan 20 02:07:16 2013 UTC (12 years, 3 months ago) by greg
Branch: MAIN
Log Message:
Added documentation for new gendaymtx tool

File Contents

# User Rev Content
1 greg 1.1 .\" RCSid $Id$
2     .TH GENDAYMTX 1 01/19/13 RADIANCE
3     .SH NAME
4     gendaymtx - generate an annual Perez sky matrix from a weather tape
5     .SH SYNOPSIS
6     .B gendaymtx
7     [
8     .B "\-v"
9     ][
10     .B "\-d|\-s"
11     ][
12     .B "\-m N"
13     ][
14     .B "\-g r g b"
15     ][
16     .B "\-c r g b"
17     ][
18     .B "-o{f|d}"
19     ]
20     [
21     .B "tape.wea"
22     ]
23     .SH DESCRIPTION
24     .I Gendaymtx
25     takes a weather tape as input and produces a matrix of sky patch
26     values using the Perez all-weather model.
27     The weather tape is assumed to be in the simple ASCII format understood
28     by DAYSIM, which contains a short header with the site parameters followed
29     by the month, day, standard time, direct normal and diffuse horizontal
30     irradiance values, one time step per line.
31     Each time step line is used to compute a column in the output matrix,
32     where rows correspond to sky patch positions, starting with 0 for
33     the ground and continuing to 145 for the zenith using the default
34     .I "\-m 1"
35     parameter setting.
36     .PP
37     Increasing the
38     .I \-m
39     parameter, typically by factors of two, yields a higher resolution
40     sky using the Reinhart patch subdivision.
41     For example, setting
42     .I "\-m 4"
43     yields a sky with 2305 patches plus one patch for the ground.
44     Each matrix entry is in fact three values, corresponding to
45     red green and blue radiance channels (watts/sr/meter^2).
46     Thus, an hourly weather tape for an entire year would
47     yield 8760x3 (26280) values per output line (row).
48     .PP
49     The
50     .I \-c
51     option may be used to specify a color for the sky.
52     The gray value should equal 1 for proper energy balance
53     The default sky color is
54     .I "\-c 0.960 1.004 1.118".
55     Similarly, the
56     .I \-g
57     option may be used to specify a ground color.
58     The default value is
59     .I "\-g 0.2 0.2 0.2"
60     corresponding to a 20% gray.
61     .PP
62     The
63     .I \-d
64     option may be used to produce a sun-only matrix, with no sky contributions.
65     Alternatively, the
66     .I \-s
67     option may be used to exclude any direct solar component from the output.
68     .PP
69     The
70     .I \-of
71     or
72     .I \-od
73     option may be used to specify binary float or double output, respectively.
74     This is much faster to write and to read, and is therefore preferred on
75     systems that support it.
76     (MS Windows is not one of them.)\0
77     Finally, the
78     .I \-v
79     option will enable verbose reporting, which is mostly useful for
80     finding out how many time steps are actually in the weather tape.
81     .SH EXAMPLES
82     Produce an uncolored Tregenza sky matrix without solar direct:
83     .IP "" .2i
84     gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
85     .PP
86     Produce an hourly, annual Reinhart sky matrix
87     with 2306 patches including solar contributions
88     and send float output to
89     .I dctimestep(1)
90     to compute a sensor value matrix:
91     .IP "" .2i
92     gendaymtx -m 4 -of VancouverBC.wea | dctimestep -if -n 8760 DCoef.mtx > res.dat
93     .SH AUTHORS
94     Ian Ashdown wrote most of the code,
95     based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
96     Greg Ward wrote the final parameter parsing and weather tape conversion.
97     .SH "SEE ALSO"
98     dctimestep(1), genBSDF(1), gendaylit(1), genskyvec(1), rcontrib(1)