man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.17 2024/04/26 23:10:59 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 "\-A"
][
.B "\-d|\-s|\-n"
][
.B "\-u"
][
.B "\-D sunfile"
[
.B "\-M sunmods"
]][
.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 "\-i intvl"
]
[
.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 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 \-A
option tells
.I gendaymtx
to generate a single column corresponding to an average sky
computed over all the input time steps, rather than one
column per time step.
.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
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.
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 other sky and ground patches unaffected.
.PP
The
.I \-u
option ignores input times when the sun is below the horizon.
This is a convenient way to average daylight hours only with the
.I \-A
option or to ensure that matrix entries correspond to solar positions
produced with the
.I \-D
option, described below.
.PP
The
.I \-n
option may be used if no matrix output is desired at all.
This may be used to merely check the input, or in combination with the
.I \-D
option, below.
.PP
The
.I \-D
option may be used to specify an output file to contain a list of
solar positions and intensities corresponding to time steps in the
weather tape where the sun has any portion above the horizon.
Sun radiance values may be zero if the direct amount is zero on the input.
Sun modifiers and names will be indexed by the minute, numbered from
midnight, January 1st.
If a hyphen ('-') is given as the argument to
.I \-D,
then the sun descriptions  will be directed to the standard output.
This implies the
.I \-n
option just described.
If the
.I \-M
option is given as well, it will be used to record the modifier
names used in the
.I \-D
output, for convenient input to
.I rcontrib(1)
and
.I rfluxmtx(1).
.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 \-i
option specifies the actual capture interval in minutes of the original
weather data.
Please see the man page for
.I gendaylit
to understand this correction, which is applied only near sunrise and
sunset.
.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), gensdaymtx(1), gensky(1),
genskyvec(1), genssky(1),
rcollate(1), rcontrib(1), rfluxmtx(1), rmtxop(1), xform(1)
Revision:	1.18
Committed:	Mon Aug 5 17:23:56 2024 UTC (9 months, 1 week ago) by greg
Branch:	MAIN
Changes since 1.17:	+4 -3 lines
Log Message:	docs: Slight wording modifications and added links to other tools
#	User	Rev	Content
1	greg	1.18	.\" RCSid $Id: gendaymtx.1,v 1.17 2024/04/26 23:10:59 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	1.10	.B "\-A"
13			][
14	greg	1.11	.B "\-d\|\-s\|\-n"
15			][
16	greg	1.14	.B "\-u"
17			][
18	greg	1.11	.B "\-D sunfile"
19	greg	1.13	[
20	greg	1.12	.B "\-M sunmods"
21	greg	1.13	]][
22	greg	1.2	.B "\-r deg"
23			][
24	greg	1.1	.B "\-m N"
25			][
26			.B "\-g r g b"
27			][
28			.B "\-c r g b"
29			][
30			.B "-o{f\|d}"
31	greg	1.4	][
32	greg	1.17	.B "\-O{0\|1}"
33			][
34			.B "\-i intvl"
35	greg	1.1	]
36			[
37			.B "tape.wea"
38			]
39			.SH DESCRIPTION
40			.I Gendaymtx
41			takes a weather tape as input and produces a matrix of sky patch
42			values using the Perez all-weather model.
43			The weather tape is assumed to be in the simple ASCII format understood
44			by DAYSIM, which contains a short header with the site parameters followed
45			by the month, day, standard time, direct normal and diffuse horizontal
46			irradiance values, one time step per line.
47			Each time step line is used to compute a column in the output matrix,
48			where rows correspond to sky patch positions, starting with 0 for
49			the ground and continuing to 145 for the zenith using the default
50			.I "\-m 1"
51			parameter setting.
52			.PP
53			Increasing the
54			.I \-m
55	greg	1.11	parameter yields a higher resolution
56	greg	1.1	sky using the Reinhart patch subdivision.
57			For example, setting
58			.I "\-m 4"
59			yields a sky with 2305 patches plus one patch for the ground.
60			Each matrix entry is in fact three values, corresponding to
61			red green and blue radiance channels (watts/sr/meter^2).
62			Thus, an hourly weather tape for an entire year would
63			yield 8760x3 (26280) values per output line (row).
64			.PP
65			The
66	greg	1.10	.I \-A
67			option tells
68			.I gendaymtx
69			to generate a single column corresponding to an average sky
70			computed over all the input time steps, rather than one
71			column per time step.
72			.PP
73			The
74	greg	1.1	.I \-c
75			option may be used to specify a color for the sky.
76	greg	1.7	The gray value should equal 1 for proper energy balance.
77	greg	1.1	The default sky color is
78			.I "\-c 0.960 1.004 1.118".
79			Similarly, the
80			.I \-g
81			option may be used to specify a ground color.
82			The default value is
83			.I "\-g 0.2 0.2 0.2"
84			corresponding to a 20% gray.
85			.PP
86	greg	1.16	If there is a sun in the description,
87			.I gendaymtx
88			will include its contribution in the four nearest sky patches,
89			distributing energy according to centroid proximity.
90	greg	1.1	The
91			.I \-d
92	greg	1.9	option may be used to produce a sun-only matrix, with no sky contributions,
93			and the ground patch also set to zero.
94	greg	1.1	Alternatively, the
95			.I \-s
96	greg	1.9	option may be used to exclude any direct solar component from the output,
97	greg	1.16	with the other sky and ground patches unaffected.
98	greg	1.1	.PP
99	greg	1.11	The
100	greg	1.13	.I \-u
101			option ignores input times when the sun is below the horizon.
102			This is a convenient way to average daylight hours only with the
103			.I \-A
104			option or to ensure that matrix entries correspond to solar positions
105			produced with the
106			.I \-D
107			option, described below.
108			.PP
109			The
110	greg	1.11	.I \-n
111	greg	1.13	option may be used if no matrix output is desired at all.
112	greg	1.11	This may be used to merely check the input, or in combination with the
113			.I \-D
114			option, below.
115			.PP
116			The
117			.I \-D
118			option may be used to specify an output file to contain a list of
119			solar positions and intensities corresponding to time steps in the
120	greg	1.15	weather tape where the sun has any portion above the horizon.
121	greg	1.12	Sun radiance values may be zero if the direct amount is zero on the input.
122			Sun modifiers and names will be indexed by the minute, numbered from
123			midnight, January 1st.
124			If a hyphen ('-') is given as the argument to
125			.I \-D,
126			then the sun descriptions will be directed to the standard output.
127			This implies the
128			.I \-n
129			option just described.
130			If the
131			.I \-M
132			option is given as well, it will be used to record the modifier
133			names used in the
134			.I \-D
135			output, for convenient input to
136			.I rcontrib(1)
137			and
138			.I rfluxmtx(1).
139	greg	1.11	.PP
140	greg	1.3	By default,
141			.I gendaymtx
142			assumes the positive Y-axis points north such that the first sky patch
143			is in the Y-axis direction on the horizon, the second patch is just
144			west of that, and so on spiraling around to the final patch near the zenith.
145	greg	1.1	The
146	greg	1.2	.I \-r
147			(or
148			.I \-rz)
149			option rotates the sky the specified number of degrees counter-clockwise
150	greg	1.3	about the zenith, i.e., west of north.
151	greg	1.2	This is in keeping with the effect of passing the output of
152			.I gensky(1)
153			or
154			.I gendaylit(1)
155			through
156			.I xform(1)
157			using a similar transform.
158			.PP
159			The
160	greg	1.17	.I \-i
161			option specifies the actual capture interval in minutes of the original
162			weather data.
163			Please see the man page for
164			.I gendaylit
165			to understand this correction, which is applied only near sunrise and
166			sunset.
167			.PP
168			The
169	greg	1.1	.I \-of
170			or
171			.I \-od
172			option may be used to specify binary float or double output, respectively.
173			This is much faster to write and to read, and is therefore preferred on
174			systems that support it.
175			(MS Windows is not one of them.)\0
176	greg	1.4	The
177			.I \-O1
178			option specifies that output should be total solar radiance rather
179			than visible radiance.
180	greg	1.6	The
181			.I \-h
182			option prevents the output of the usual header information.
183	greg	1.1	Finally, the
184			.I \-v
185			option will enable verbose reporting, which is mostly useful for
186			finding out how many time steps are actually in the weather tape.
187			.SH EXAMPLES
188			Produce an uncolored Tregenza sky matrix without solar direct:
189			.IP "" .2i
190			gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
191			.PP
192			Produce an hourly, annual Reinhart sky matrix
193			with 2306 patches including solar contributions
194			and send float output to
195			.I dctimestep(1)
196			to compute a sensor value matrix:
197			.IP "" .2i
198			gendaymtx -m 4 -of VancouverBC.wea \| dctimestep -if -n 8760 DCoef.mtx > res.dat
199			.SH AUTHORS
200			Ian Ashdown wrote most of the code,
201			based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
202			Greg Ward wrote the final parameter parsing and weather tape conversion.
203			.SH "SEE ALSO"
204	greg	1.18	dctimestep(1), genBSDF(1), gendaylit(1), gensdaymtx(1), gensky(1),
205			genskyvec(1), genssky(1),
206			rcollate(1), rcontrib(1), rfluxmtx(1), rmtxop(1), xform(1)