man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.15 2021/02/17 02:30:08 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 "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 \-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), rfluxmtx(1), xform(1)
Revision:	1.16
Committed:	Sat Aug 13 17:24:56 2022 UTC (2 years, 10 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R4
Changes since 1.15:	+6 -6 lines
Log Message:	docs(gendaymtx): wording improvement
#	Content
1	.\" RCSid $Id: gendaymtx.1,v 1.15 2021/02/17 02:30:08 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 "\-h"
11	][
12	.B "\-A"
13	][
14	.B "\-d\|\-s\|\-n"
15	][
16	.B "\-u"
17	][
18	.B "\-D sunfile"
19	[
20	.B "\-M sunmods"
21	]][
22	.B "\-r deg"
23	][
24	.B "\-m N"
25	][
26	.B "\-g r g b"
27	][
28	.B "\-c r g b"
29	][
30	.B "-o{f\|d}"
31	][
32	.B "-O{0\|1}"
33	]
34	[
35	.B "tape.wea"
36	]
37	.SH DESCRIPTION
38	.I Gendaymtx
39	takes a weather tape as input and produces a matrix of sky patch
40	values using the Perez all-weather model.
41	The weather tape is assumed to be in the simple ASCII format understood
42	by DAYSIM, which contains a short header with the site parameters followed
43	by the month, day, standard time, direct normal and diffuse horizontal
44	irradiance values, one time step per line.
45	Each time step line is used to compute a column in the output matrix,
46	where rows correspond to sky patch positions, starting with 0 for
47	the ground and continuing to 145 for the zenith using the default
48	.I "\-m 1"
49	parameter setting.
50	.PP
51	Increasing the
52	.I \-m
53	parameter yields a higher resolution
54	sky using the Reinhart patch subdivision.
55	For example, setting
56	.I "\-m 4"
57	yields a sky with 2305 patches plus one patch for the ground.
58	Each matrix entry is in fact three values, corresponding to
59	red green and blue radiance channels (watts/sr/meter^2).
60	Thus, an hourly weather tape for an entire year would
61	yield 8760x3 (26280) values per output line (row).
62	.PP
63	The
64	.I \-A
65	option tells
66	.I gendaymtx
67	to generate a single column corresponding to an average sky
68	computed over all the input time steps, rather than one
69	column per time step.
70	.PP
71	The
72	.I \-c
73	option may be used to specify a color for the sky.
74	The gray value should equal 1 for proper energy balance.
75	The default sky color is
76	.I "\-c 0.960 1.004 1.118".
77	Similarly, the
78	.I \-g
79	option may be used to specify a ground color.
80	The default value is
81	.I "\-g 0.2 0.2 0.2"
82	corresponding to a 20% gray.
83	.PP
84	If there is a sun in the description,
85	.I gendaymtx
86	will include its contribution in the four nearest sky patches,
87	distributing energy according to centroid proximity.
88	The
89	.I \-d
90	option may be used to produce a sun-only matrix, with no sky contributions,
91	and the ground patch also set to zero.
92	Alternatively, the
93	.I \-s
94	option may be used to exclude any direct solar component from the output,
95	with the other sky and ground patches unaffected.
96	.PP
97	The
98	.I \-u
99	option ignores input times when the sun is below the horizon.
100	This is a convenient way to average daylight hours only with the
101	.I \-A
102	option or to ensure that matrix entries correspond to solar positions
103	produced with the
104	.I \-D
105	option, described below.
106	.PP
107	The
108	.I \-n
109	option may be used if no matrix output is desired at all.
110	This may be used to merely check the input, or in combination with the
111	.I \-D
112	option, below.
113	.PP
114	The
115	.I \-D
116	option may be used to specify an output file to contain a list of
117	solar positions and intensities corresponding to time steps in the
118	weather tape where the sun has any portion above the horizon.
119	Sun radiance values may be zero if the direct amount is zero on the input.
120	Sun modifiers and names will be indexed by the minute, numbered from
121	midnight, January 1st.
122	If a hyphen ('-') is given as the argument to
123	.I \-D,
124	then the sun descriptions will be directed to the standard output.
125	This implies the
126	.I \-n
127	option just described.
128	If the
129	.I \-M
130	option is given as well, it will be used to record the modifier
131	names used in the
132	.I \-D
133	output, for convenient input to
134	.I rcontrib(1)
135	and
136	.I rfluxmtx(1).
137	.PP
138	By default,
139	.I gendaymtx
140	assumes the positive Y-axis points north such that the first sky patch
141	is in the Y-axis direction on the horizon, the second patch is just
142	west of that, and so on spiraling around to the final patch near the zenith.
143	The
144	.I \-r
145	(or
146	.I \-rz)
147	option rotates the sky the specified number of degrees counter-clockwise
148	about the zenith, i.e., west of north.
149	This is in keeping with the effect of passing the output of
150	.I gensky(1)
151	or
152	.I gendaylit(1)
153	through
154	.I xform(1)
155	using a similar transform.
156	.PP
157	The
158	.I \-of
159	or
160	.I \-od
161	option may be used to specify binary float or double output, respectively.
162	This is much faster to write and to read, and is therefore preferred on
163	systems that support it.
164	(MS Windows is not one of them.)\0
165	The
166	.I \-O1
167	option specifies that output should be total solar radiance rather
168	than visible radiance.
169	The
170	.I \-h
171	option prevents the output of the usual header information.
172	Finally, the
173	.I \-v
174	option will enable verbose reporting, which is mostly useful for
175	finding out how many time steps are actually in the weather tape.
176	.SH EXAMPLES
177	Produce an uncolored Tregenza sky matrix without solar direct:
178	.IP "" .2i
179	gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
180	.PP
181	Produce an hourly, annual Reinhart sky matrix
182	with 2306 patches including solar contributions
183	and send float output to
184	.I dctimestep(1)
185	to compute a sensor value matrix:
186	.IP "" .2i
187	gendaymtx -m 4 -of VancouverBC.wea \| dctimestep -if -n 8760 DCoef.mtx > res.dat
188	.SH AUTHORS
189	Ian Ashdown wrote most of the code,
190	based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
191	Greg Ward wrote the final parameter parsing and weather tape conversion.
192	.SH "SEE ALSO"
193	dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1),
194	rcollate(1), rcontrib(1), rfluxmtx(1), xform(1)