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root/radiance/ray/doc/man/man1/gendaymtx.1
Revision: 1.6
Committed: Fri May 30 00:00:54 2014 UTC (10 years, 11 months ago) by greg
Branch: MAIN
Changes since 1.5: +6 -1 lines
Log Message:
Added NROWS, NCOLS and NCOMP to matrix headers

File Contents

# User Rev Content
1 greg 1.6 .\" RCSid $Id: gendaymtx.1,v 1.5 2013/09/05 17:53:22 greg Exp $
2 greg 1.1 .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 greg 1.6 .B "\-h"
11     ][
12 greg 1.1 .B "\-d|\-s"
13     ][
14 greg 1.2 .B "\-r deg"
15     ][
16 greg 1.1 .B "\-m N"
17     ][
18     .B "\-g r g b"
19     ][
20     .B "\-c r g b"
21     ][
22     .B "-o{f|d}"
23 greg 1.4 ][
24     .B "-O{0|1}"
25 greg 1.1 ]
26     [
27     .B "tape.wea"
28     ]
29     .SH DESCRIPTION
30     .I Gendaymtx
31     takes a weather tape as input and produces a matrix of sky patch
32     values using the Perez all-weather model.
33     The weather tape is assumed to be in the simple ASCII format understood
34     by DAYSIM, which contains a short header with the site parameters followed
35     by the month, day, standard time, direct normal and diffuse horizontal
36     irradiance values, one time step per line.
37     Each time step line is used to compute a column in the output matrix,
38     where rows correspond to sky patch positions, starting with 0 for
39     the ground and continuing to 145 for the zenith using the default
40     .I "\-m 1"
41     parameter setting.
42     .PP
43     Increasing the
44     .I \-m
45     parameter, typically by factors of two, yields a higher resolution
46     sky using the Reinhart patch subdivision.
47     For example, setting
48     .I "\-m 4"
49     yields a sky with 2305 patches plus one patch for the ground.
50     Each matrix entry is in fact three values, corresponding to
51     red green and blue radiance channels (watts/sr/meter^2).
52     Thus, an hourly weather tape for an entire year would
53     yield 8760x3 (26280) values per output line (row).
54     .PP
55     The
56     .I \-c
57     option may be used to specify a color for the sky.
58     The gray value should equal 1 for proper energy balance
59     The default sky color is
60     .I "\-c 0.960 1.004 1.118".
61     Similarly, the
62     .I \-g
63     option may be used to specify a ground color.
64     The default value is
65     .I "\-g 0.2 0.2 0.2"
66     corresponding to a 20% gray.
67     .PP
68     The
69     .I \-d
70     option may be used to produce a sun-only matrix, with no sky contributions.
71     Alternatively, the
72     .I \-s
73     option may be used to exclude any direct solar component from the output.
74     .PP
75 greg 1.3 By default,
76     .I gendaymtx
77     assumes the positive Y-axis points north such that the first sky patch
78     is in the Y-axis direction on the horizon, the second patch is just
79     west of that, and so on spiraling around to the final patch near the zenith.
80 greg 1.1 The
81 greg 1.2 .I \-r
82     (or
83     .I \-rz)
84     option rotates the sky the specified number of degrees counter-clockwise
85 greg 1.3 about the zenith, i.e., west of north.
86 greg 1.2 This is in keeping with the effect of passing the output of
87     .I gensky(1)
88     or
89     .I gendaylit(1)
90     through
91     .I xform(1)
92     using a similar transform.
93     .PP
94     The
95 greg 1.1 .I \-of
96     or
97     .I \-od
98     option may be used to specify binary float or double output, respectively.
99     This is much faster to write and to read, and is therefore preferred on
100     systems that support it.
101     (MS Windows is not one of them.)\0
102 greg 1.4 The
103     .I \-O1
104     option specifies that output should be total solar radiance rather
105     than visible radiance.
106 greg 1.6 The
107     .I \-h
108     option prevents the output of the usual header information.
109 greg 1.1 Finally, the
110     .I \-v
111     option will enable verbose reporting, which is mostly useful for
112     finding out how many time steps are actually in the weather tape.
113     .SH EXAMPLES
114     Produce an uncolored Tregenza sky matrix without solar direct:
115     .IP "" .2i
116     gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
117     .PP
118     Produce an hourly, annual Reinhart sky matrix
119     with 2306 patches including solar contributions
120     and send float output to
121     .I dctimestep(1)
122     to compute a sensor value matrix:
123     .IP "" .2i
124     gendaymtx -m 4 -of VancouverBC.wea | dctimestep -if -n 8760 DCoef.mtx > res.dat
125     .SH AUTHORS
126     Ian Ashdown wrote most of the code,
127     based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
128     Greg Ward wrote the final parameter parsing and weather tape conversion.
129     .SH "SEE ALSO"
130 greg 1.5 dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1),
131     rcollate(1), rcontrib(1), xform(1)