man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.8 2018/05/24 15:21:15 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 "\-h"
][
.B "\-d|\-s"
][
.B "\-r deg"
][
.B "\-m N"
][
.B "\-g r g b"
][
.B "\-c r g b"
][
.B "-o{f|d}"
][
.B "-O{0|1}"
]
[
.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,
and the ground patch also set to zero.
Alternatively, the
.I \-s
option may be used to exclude any direct solar component from the output,
with the rest of the sky and ground patch unaffected.
If there is a sun in the description,
.I gendaymtx
will include its contribution in the four nearest sky patches,
distributing energy according to centroid proximity.
.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
The
.I \-O1
option specifies that output should be total solar radiance rather
than visible radiance.
The
.I \-h
option prevents the output of the usual header information.
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),
rcollate(1), rcontrib(1), xform(1)
Revision:	1.9
Committed:	Tue May 28 15:19:17 2019 UTC (5 years, 11 months ago) by greg
Branch:	MAIN
Changes since 1.8:	+5 -3 lines
Log Message:	Clarified wording as recommended by Lars.
#	User	Rev	Content
1	greg	1.9	.\" RCSid $Id: gendaymtx.1,v 1.8 2018/05/24 15:21:15 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	greg	1.7	The gray value should equal 1 for proper energy balance.
59	greg	1.1	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	greg	1.9	option may be used to produce a sun-only matrix, with no sky contributions,
71			and the ground patch also set to zero.
72	greg	1.1	Alternatively, the
73			.I \-s
74	greg	1.9	option may be used to exclude any direct solar component from the output,
75			with the rest of the sky and ground patch unaffected.
76	greg	1.8	If there is a sun in the description,
77			.I gendaymtx
78			will include its contribution in the four nearest sky patches,
79			distributing energy according to centroid proximity.
80	greg	1.1	.PP
81	greg	1.3	By default,
82			.I gendaymtx
83			assumes the positive Y-axis points north such that the first sky patch
84			is in the Y-axis direction on the horizon, the second patch is just
85			west of that, and so on spiraling around to the final patch near the zenith.
86	greg	1.1	The
87	greg	1.2	.I \-r
88			(or
89			.I \-rz)
90			option rotates the sky the specified number of degrees counter-clockwise
91	greg	1.3	about the zenith, i.e., west of north.
92	greg	1.2	This is in keeping with the effect of passing the output of
93			.I gensky(1)
94			or
95			.I gendaylit(1)
96			through
97			.I xform(1)
98			using a similar transform.
99			.PP
100			The
101	greg	1.1	.I \-of
102			or
103			.I \-od
104			option may be used to specify binary float or double output, respectively.
105			This is much faster to write and to read, and is therefore preferred on
106			systems that support it.
107			(MS Windows is not one of them.)\0
108	greg	1.4	The
109			.I \-O1
110			option specifies that output should be total solar radiance rather
111			than visible radiance.
112	greg	1.6	The
113			.I \-h
114			option prevents the output of the usual header information.
115	greg	1.1	Finally, the
116			.I \-v
117			option will enable verbose reporting, which is mostly useful for
118			finding out how many time steps are actually in the weather tape.
119			.SH EXAMPLES
120			Produce an uncolored Tregenza sky matrix without solar direct:
121			.IP "" .2i
122			gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
123			.PP
124			Produce an hourly, annual Reinhart sky matrix
125			with 2306 patches including solar contributions
126			and send float output to
127			.I dctimestep(1)
128			to compute a sensor value matrix:
129			.IP "" .2i
130			gendaymtx -m 4 -of VancouverBC.wea \| dctimestep -if -n 8760 DCoef.mtx > res.dat
131			.SH AUTHORS
132			Ian Ashdown wrote most of the code,
133			based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
134			Greg Ward wrote the final parameter parsing and weather tape conversion.
135			.SH "SEE ALSO"
136	greg	1.5	dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1),
137			rcollate(1), rcontrib(1), xform(1)