man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.12 2020/04/13 17:12:19 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 "\-h"
][
.B "\-A"
][
.B "\-d|\-s|\-n"
][
.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
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
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 horizion.
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:	1.13
Committed:	Sat Aug 15 03:28:56 2020 UTC (4 years, 10 months ago) by greg
Branch:	MAIN
CVS Tags:	rad5R3
Changes since 1.12:	+14 -4 lines
Log Message:	feat(gendaymtx): added -u option for daylight hours only
#	Content
1	.\" RCSid $Id: gendaymtx.1,v 1.12 2020/04/13 17:12:19 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 "\-h"
11	][
12	.B "\-A"
13	][
14	.B "\-d\|\-s\|\-n"
15	][
16	.B "\-D sunfile"
17	[
18	.B "\-M sunmods"
19	]][
20	.B "\-r deg"
21	][
22	.B "\-m N"
23	][
24	.B "\-g r g b"
25	][
26	.B "\-c r g b"
27	][
28	.B "-o{f\|d}"
29	][
30	.B "-O{0\|1}"
31	]
32	[
33	.B "tape.wea"
34	]
35	.SH DESCRIPTION
36	.I Gendaymtx
37	takes a weather tape as input and produces a matrix of sky patch
38	values using the Perez all-weather model.
39	The weather tape is assumed to be in the simple ASCII format understood
40	by DAYSIM, which contains a short header with the site parameters followed
41	by the month, day, standard time, direct normal and diffuse horizontal
42	irradiance values, one time step per line.
43	Each time step line is used to compute a column in the output matrix,
44	where rows correspond to sky patch positions, starting with 0 for
45	the ground and continuing to 145 for the zenith using the default
46	.I "\-m 1"
47	parameter setting.
48	.PP
49	Increasing the
50	.I \-m
51	parameter yields a higher resolution
52	sky using the Reinhart patch subdivision.
53	For example, setting
54	.I "\-m 4"
55	yields a sky with 2305 patches plus one patch for the ground.
56	Each matrix entry is in fact three values, corresponding to
57	red green and blue radiance channels (watts/sr/meter^2).
58	Thus, an hourly weather tape for an entire year would
59	yield 8760x3 (26280) values per output line (row).
60	.PP
61	The
62	.I \-A
63	option tells
64	.I gendaymtx
65	to generate a single column corresponding to an average sky
66	computed over all the input time steps, rather than one
67	column per time step.
68	.PP
69	The
70	.I \-c
71	option may be used to specify a color for the sky.
72	The gray value should equal 1 for proper energy balance.
73	The default sky color is
74	.I "\-c 0.960 1.004 1.118".
75	Similarly, the
76	.I \-g
77	option may be used to specify a ground color.
78	The default value is
79	.I "\-g 0.2 0.2 0.2"
80	corresponding to a 20% gray.
81	.PP
82	The
83	.I \-d
84	option may be used to produce a sun-only matrix, with no sky contributions,
85	and the ground patch also set to zero.
86	Alternatively, the
87	.I \-s
88	option may be used to exclude any direct solar component from the output,
89	with the rest of the sky and ground patch unaffected.
90	If there is a sun in the description,
91	.I gendaymtx
92	will include its contribution in the four nearest sky patches,
93	distributing energy according to centroid proximity.
94	.PP
95	The
96	.I \-u
97	option ignores input times when the sun is below the horizon.
98	This is a convenient way to average daylight hours only with the
99	.I \-A
100	option or to ensure that matrix entries correspond to solar positions
101	produced with the
102	.I \-D
103	option, described below.
104	.PP
105	The
106	.I \-n
107	option may be used if no matrix output is desired at all.
108	This may be used to merely check the input, or in combination with the
109	.I \-D
110	option, below.
111	.PP
112	The
113	.I \-D
114	option may be used to specify an output file to contain a list of
115	solar positions and intensities corresponding to time steps in the
116	weather tape where the sun has any portion above the horizion.
117	Sun radiance values may be zero if the direct amount is zero on the input.
118	Sun modifiers and names will be indexed by the minute, numbered from
119	midnight, January 1st.
120	If a hyphen ('-') is given as the argument to
121	.I \-D,
122	then the sun descriptions will be directed to the standard output.
123	This implies the
124	.I \-n
125	option just described.
126	If the
127	.I \-M
128	option is given as well, it will be used to record the modifier
129	names used in the
130	.I \-D
131	output, for convenient input to
132	.I rcontrib(1)
133	and
134	.I rfluxmtx(1).
135	.PP
136	By default,
137	.I gendaymtx
138	assumes the positive Y-axis points north such that the first sky patch
139	is in the Y-axis direction on the horizon, the second patch is just
140	west of that, and so on spiraling around to the final patch near the zenith.
141	The
142	.I \-r
143	(or
144	.I \-rz)
145	option rotates the sky the specified number of degrees counter-clockwise
146	about the zenith, i.e., west of north.
147	This is in keeping with the effect of passing the output of
148	.I gensky(1)
149	or
150	.I gendaylit(1)
151	through
152	.I xform(1)
153	using a similar transform.
154	.PP
155	The
156	.I \-of
157	or
158	.I \-od
159	option may be used to specify binary float or double output, respectively.
160	This is much faster to write and to read, and is therefore preferred on
161	systems that support it.
162	(MS Windows is not one of them.)\0
163	The
164	.I \-O1
165	option specifies that output should be total solar radiance rather
166	than visible radiance.
167	The
168	.I \-h
169	option prevents the output of the usual header information.
170	Finally, the
171	.I \-v
172	option will enable verbose reporting, which is mostly useful for
173	finding out how many time steps are actually in the weather tape.
174	.SH EXAMPLES
175	Produce an uncolored Tregenza sky matrix without solar direct:
176	.IP "" .2i
177	gendaymtx -m 1 -c 1 1 1 -s Detroit.wea > Detroit.mtx
178	.PP
179	Produce an hourly, annual Reinhart sky matrix
180	with 2306 patches including solar contributions
181	and send float output to
182	.I dctimestep(1)
183	to compute a sensor value matrix:
184	.IP "" .2i
185	gendaymtx -m 4 -of VancouverBC.wea \| dctimestep -if -n 8760 DCoef.mtx > res.dat
186	.SH AUTHORS
187	Ian Ashdown wrote most of the code,
188	based on Jean-Jacques Delaunay's original gendaylit(1) implementation.
189	Greg Ward wrote the final parameter parsing and weather tape conversion.
190	.SH "SEE ALSO"
191	dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1),
192	rcollate(1), rcontrib(1), rfluxmtx(1), xform(1)