man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.2 2013/02/05 06:00:19 greg Exp $
.TH GENDAYMTX 1 01/19/13 RADIANCE
.SH NAME
gendaymtx - generate an annual Perez sky matrix from a weather tape
.SH SYNOPSIS
.B gendaymtx
[
.B "\-v"
][
.B "\-d|\-s"
][
.B "\-r deg"
][
.B "\-m N"
][
.B "\-g r g b"
][
.B "\-c r g b"
][
.B "-o{f|d}"
]
[
.B "tape.wea"
]
.SH DESCRIPTION
.I Gendaymtx
takes a weather tape as input and produces a matrix of sky patch
values using the Perez all-weather model.
The weather tape is assumed to be in the simple ASCII format understood
by DAYSIM, which contains a short header with the site parameters followed
by the month, day, standard time, direct normal and diffuse horizontal
irradiance values, one time step per line.
Each time step line is used to compute a column in the output matrix,
where rows correspond to sky patch positions, starting with 0 for
the ground and continuing to 145 for the zenith using the default
.I "\-m 1"
parameter setting.
.PP
Increasing the
.I \-m
parameter, typically by factors of two, yields a higher resolution
sky using the Reinhart patch subdivision.
For example, setting
.I "\-m 4"
yields a sky with 2305 patches plus one patch for the ground.
Each matrix entry is in fact three values, corresponding to
red green and blue radiance channels (watts/sr/meter^2).
Thus, an hourly weather tape for an entire year would
yield 8760x3 (26280) values per output line (row).
.PP
The
.I \-c
option may be used to specify a color for the sky.
The gray value should equal 1 for proper energy balance
The default sky color is
.I "\-c 0.960 1.004 1.118".
Similarly, the
.I \-g
option may be used to specify a ground color.
The default value is
.I "\-g 0.2 0.2 0.2"
corresponding to a 20% gray.
.PP
The
.I \-d
option may be used to produce a sun-only matrix, with no sky contributions.
Alternatively, the
.I \-s
option may be used to exclude any direct solar component from the output.
.PP
By default,
.I gendaymtx
assumes the positive Y-axis points north such that the first sky patch
is in the Y-axis direction on the horizon, the second patch is just
west of that, and so on spiraling around to the final patch near the zenith.
The
.I \-r
(or
.I \-rz)
option rotates the sky the specified number of degrees counter-clockwise
about the zenith, i.e., west of north.
This is in keeping with the effect of passing the output of
.I gensky(1)
or
.I gendaylit(1)
through
.I xform(1)
using a similar transform.
.PP
The
.I \-of
or
.I \-od
option may be used to specify binary float or double output, respectively.
This is much faster to write and to read, and is therefore preferred on
systems that support it.
(MS Windows is not one of them.)\0
Finally, the
.I \-v
option will enable verbose reporting, which is mostly useful for
finding out how many time steps are actually in the weather tape.
.SH EXAMPLES
Produce an uncolored Tregenza sky matrix without solar direct:
.IP "" .2i
gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
.PP
Produce an hourly, annual Reinhart sky matrix
with 2306 patches including solar contributions
and send float output to
.I dctimestep(1)
to compute a sensor value matrix:
.IP "" .2i
gendaymtx -m 4 -of VancouverBC.wea | dctimestep -if -n 8760 DCoef.mtx > res.dat
.SH AUTHORS
Ian Ashdown wrote most of the code,
based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
Greg Ward wrote the final parameter parsing and weather tape conversion.
.SH "SEE ALSO"
dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1), rcontrib(1),
xform(1)
Revision:	1.3
Committed:	Tue Feb 5 19:31:40 2013 UTC (12 years, 3 months ago) by greg
Branch:	MAIN
Changes since 1.2:	+7 -2 lines
Log Message:	Added clarification about output directions
#	Content
1	.\" RCSid $Id: gendaymtx.1,v 1.2 2013/02/05 06:00:19 greg Exp $
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 "\-r deg"
13	][
14	.B "\-m N"
15	][
16	.B "\-g r g b"
17	][
18	.B "\-c r g b"
19	][
20	.B "-o{f\|d}"
21	]
22	[
23	.B "tape.wea"
24	]
25	.SH DESCRIPTION
26	.I Gendaymtx
27	takes a weather tape as input and produces a matrix of sky patch
28	values using the Perez all-weather model.
29	The weather tape is assumed to be in the simple ASCII format understood
30	by DAYSIM, which contains a short header with the site parameters followed
31	by the month, day, standard time, direct normal and diffuse horizontal
32	irradiance values, one time step per line.
33	Each time step line is used to compute a column in the output matrix,
34	where rows correspond to sky patch positions, starting with 0 for
35	the ground and continuing to 145 for the zenith using the default
36	.I "\-m 1"
37	parameter setting.
38	.PP
39	Increasing the
40	.I \-m
41	parameter, typically by factors of two, yields a higher resolution
42	sky using the Reinhart patch subdivision.
43	For example, setting
44	.I "\-m 4"
45	yields a sky with 2305 patches plus one patch for the ground.
46	Each matrix entry is in fact three values, corresponding to
47	red green and blue radiance channels (watts/sr/meter^2).
48	Thus, an hourly weather tape for an entire year would
49	yield 8760x3 (26280) values per output line (row).
50	.PP
51	The
52	.I \-c
53	option may be used to specify a color for the sky.
54	The gray value should equal 1 for proper energy balance
55	The default sky color is
56	.I "\-c 0.960 1.004 1.118".
57	Similarly, the
58	.I \-g
59	option may be used to specify a ground color.
60	The default value is
61	.I "\-g 0.2 0.2 0.2"
62	corresponding to a 20% gray.
63	.PP
64	The
65	.I \-d
66	option may be used to produce a sun-only matrix, with no sky contributions.
67	Alternatively, the
68	.I \-s
69	option may be used to exclude any direct solar component from the output.
70	.PP
71	By default,
72	.I gendaymtx
73	assumes the positive Y-axis points north such that the first sky patch
74	is in the Y-axis direction on the horizon, the second patch is just
75	west of that, and so on spiraling around to the final patch near the zenith.
76	The
77	.I \-r
78	(or
79	.I \-rz)
80	option rotates the sky the specified number of degrees counter-clockwise
81	about the zenith, i.e., west of north.
82	This is in keeping with the effect of passing the output of
83	.I gensky(1)
84	or
85	.I gendaylit(1)
86	through
87	.I xform(1)
88	using a similar transform.
89	.PP
90	The
91	.I \-of
92	or
93	.I \-od
94	option may be used to specify binary float or double output, respectively.
95	This is much faster to write and to read, and is therefore preferred on
96	systems that support it.
97	(MS Windows is not one of them.)\0
98	Finally, the
99	.I \-v
100	option will enable verbose reporting, which is mostly useful for
101	finding out how many time steps are actually in the weather tape.
102	.SH EXAMPLES
103	Produce an uncolored Tregenza sky matrix without solar direct:
104	.IP "" .2i
105	gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
106	.PP
107	Produce an hourly, annual Reinhart sky matrix
108	with 2306 patches including solar contributions
109	and send float output to
110	.I dctimestep(1)
111	to compute a sensor value matrix:
112	.IP "" .2i
113	gendaymtx -m 4 -of VancouverBC.wea \| dctimestep -if -n 8760 DCoef.mtx > res.dat
114	.SH AUTHORS
115	Ian Ashdown wrote most of the code,
116	based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
117	Greg Ward wrote the final parameter parsing and weather tape conversion.
118	.SH "SEE ALSO"
119	dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1), rcontrib(1),
120	xform(1)