man/man1/gendaymtx.1

.\" RCSid $Id: gendaymtx.1,v 1.13 2020/08/15 03:28:56 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
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:	1.14
Committed:	Fri Sep 11 16:53:57 2020 UTC (4 years, 8 months ago) by greg
Branch:	MAIN
Changes since 1.13:	+3 -1 lines
Log Message:	docs(gendaymtx): Added missing -u option from usage line
#	User	Rev	Content
1	greg	1.14	.\" RCSid $Id: gendaymtx.1,v 1.13 2020/08/15 03:28:56 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			.B "-O{0\|1}"
33	greg	1.1	]
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	greg	1.11	parameter yields a higher resolution
54	greg	1.1	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	greg	1.10	.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	greg	1.1	.I \-c
73			option may be used to specify a color for the sky.
74	greg	1.7	The gray value should equal 1 for proper energy balance.
75	greg	1.1	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			The
85			.I \-d
86	greg	1.9	option may be used to produce a sun-only matrix, with no sky contributions,
87			and the ground patch also set to zero.
88	greg	1.1	Alternatively, the
89			.I \-s
90	greg	1.9	option may be used to exclude any direct solar component from the output,
91			with the rest of the sky and ground patch unaffected.
92	greg	1.8	If there is a sun in the description,
93			.I gendaymtx
94			will include its contribution in the four nearest sky patches,
95			distributing energy according to centroid proximity.
96	greg	1.1	.PP
97	greg	1.11	The
98	greg	1.13	.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	greg	1.11	.I \-n
109	greg	1.13	option may be used if no matrix output is desired at all.
110	greg	1.11	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	greg	1.12	weather tape where the sun has any portion above the horizion.
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	greg	1.11	.PP
138	greg	1.3	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	greg	1.1	The
144	greg	1.2	.I \-r
145			(or
146			.I \-rz)
147			option rotates the sky the specified number of degrees counter-clockwise
148	greg	1.3	about the zenith, i.e., west of north.
149	greg	1.2	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	greg	1.1	.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	greg	1.4	The
166			.I \-O1
167			option specifies that output should be total solar radiance rather
168			than visible radiance.
169	greg	1.6	The
170			.I \-h
171			option prevents the output of the usual header information.
172	greg	1.1	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	greg	1.5	dctimestep(1), genBSDF(1), gendaylit(1), gensky(1), genskyvec(1),
194	greg	1.12	rcollate(1), rcontrib(1), rfluxmtx(1), xform(1)