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Comparing ray/doc/man/man1/dctimestep.1 (file contents):
Revision 1.16 by greg, Wed Oct 23 17:00:14 2019 UTC vs.
Revision 1.23 by greg, Thu Mar 27 01:26:55 2025 UTC

# Line 11 | Line 11 | dctimestep - compute annual simulation time-step(s) vi
11   ][
12   .B "\-o ospec"
13   ][
14 < .B "\-i{f|d}
14 > .B "\-x xres"
15   ][
16 < .B "\-o{f|d|c}
16 > .B "\-y yres"
17 > ][
18 > .B "\-i{a|f|d}
19 > ][
20 > .B "\-o{a|f|d|c}
21   ]
22   .B DCspec
23   [
# Line 30 | Line 34 | dctimestep - compute annual simulation time-step(s) vi
34   ][
35   .B "\-i{f|d}
36   ][
37 < .B "\-o{f|d}
37 > .B "\-o{f|d|c}
38   ]
39   .B Vspec
40   .B Tbsdf
# Line 47 | Line 51 | is given a daylight coefficient specification and an o
51   vector or matrix, which may be read from the standard input if unspecified.
52   The daylight coefficients are multiplied against these sky values
53   and the results are written to the standard output.
54 < This may be a list of color values or a combined Radiance image,
54 > This may be a list of color values or a combined Radiance picture,
55   as explained below.
56   .PP
57   In the second form,
58   .I dctimestep
59   takes four input files, forming a matrix expression.
60 < The first argument is the View matrix file that specifies how window output
60 > The first argument is the View matrix that specifies how window output
61   directions are related to some set of measured values, such as an array of
62 < illuminance points or images.
62 > illuminance points or pictures.
63   This matrix is usually computed by
64   .I rfluxmtx(1)
65   or
# Line 102 | Line 106 | using quotes and a beginning exclamation point ('!').
106   The standard output of
107   .I dctimestep
108   is either a color vector with as many RGB triplets
109 < as there are rows in the View matrix, or a combined
106 < .I Radiance
109 > as there are rows in the View matrix, or a combined Radiance
110   picture.
111   Which output is produced depends on the first argument.
112   A regular file name will be loaded and interpreted as a matrix to
113   generate a color results vector.
114   A file specification containing a '%d' format string will be
115 < interpreted as a list of
113 < .I Radiance
115 > interpreted as a list of Radiance
116   component pictures, which will be summed according to the computed
117   vector.
118   .PP
# Line 122 | Line 124 | If the given specification contains a '%d' format stri
124   will be replaced by the time step index, starting from 0.
125   In this way, multiple output pictures may be produced,
126   or separate result vectors (one per time step).
127 + If input is a matrix rather than a set of pictures, the
128 + .I \-x
129 + and/or
130 + .I \-y
131 + options may be necessary to set the output picture size.
132 + If only one dimension is specified, the other is computed based
133 + on the number of rows in the result vectors.
134   .PP
135   A header will normally be produced on the output, unless the
136   .I \-h
137   option is specified.
138 + Default output format is ASCII text.
139   The
140   .I \-of,
141   .I \-od,
# Line 133 | Line 143 | or
143   .I \-oc
144   option may be used to specify IEEE float, double, or RGBE (picture) output
145   data, respectively.
146 + The
147 + .I \-oc
148 + option is set automatically if input is a collection of RGBE or XYZE pictures.
149   .SH EXAMPLES
150   To compute workplane illuminances at 3:30pm on Feb 10th:
151   .IP "" .2i
152   gensky 2 10 15:30 | genskyvec | dctimestep workplaneDC.dmx > Ill_02-10-1530.dat
153   .PP
154 < To compute an image at 10am on the equinox from a set of component images:
154 > To compute a picture at 10am on the equinox from a set of component pictures:
155   .IP "" .2i
156   gensky 3 21 10 | genskyvec | dctimestep dcomp%03d.hdr > view_03-21-10.hdr
157   .PP
# Line 147 | Line 160 | the Winter solstice at 2pm:
160   .IP "" .2i
161   gensky 12 21 14 | genskyvec | dctimestep IllPts.vmx Blinds20.xml Window1.dmx > Ill_12-21-14.dat
162   .PP
163 < To compute Window2's contribution to an interior view at 12 noon on the Summer solstice:
163 > To compute Window2's contribution to an interior view at 12 noon on the summer solstice:
164   .IP "" .2i
165   gensky 6 21 12 | genskyvec | dctimestep view%03d.hdr Blinds30.xml
166   Window2.dmx > view_6-21-12.hdr
# Line 171 | Line 184 | dctimestep Illum.vmx "!rmtxop -ff Blinds1.xml Windo1.x
184   To multiply two matrices into a IEEE-float result with header:
185   .IP "" .2i
186   dctimestep -of Inp1.fmx Inp2.fmx > Inp1xInp2.fmx
187 + .SH NOTES
188 + .I Dctimestep
189 + optimizes its matrix concatenation by checking for all-zero rows
190 + or columns, thus avoiding unnecessary vector multiplications.
191 + This can improve performance when a daylight matrix contains
192 + zero-filled column vectors corresponding to hours of darkness.
193 + .PP
194 + It rarely makes sense to specify the
195 + .I \-od
196 + output option with
197 + .I dctimestep,
198 + since matrix operations are carried out using 32-bit "float" values.
199 + This take less memory, but can also be less accurate than an
200 + equivalent invocation of
201 + .I rmtxop(1)
202 + or
203 + .I rcomb(1),
204 + which perform all operations on 64-bit "double" values.
205 + .PP
206 + .I Dctimestep
207 + does not accept on input or produce on output Radiance
208 + spectral pictures.
209 + This is a limitation of the implementation and its underlying
210 + data representation.
211 + Use instead the similar
212 + .I pvsum(1)
213 + tool for spectral input and output.
214   .SH AUTHOR
215   Greg Ward
216   .SH "SEE ALSO"
217 < gendaymtx(1), genskyvec(1), getinfo(1),
218 < mkillum(1), rcollate(1), rcontrib(1),
217 > dcglare(1), gendaymtx(1), genskyvec(1), getinfo(1), mkillum(1),
218 > pvsum(1), ra_rgbe(1), rcollate(1), rcomb(1), rcontrib(1), rcrop(1),
219   rfluxmtx(1), rmtxop(1), rtrace(1), vwrays(1)

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