NAME
dctimestep - compute annual simulation time-step via matrix
multiplication
SYNOPSIS
dctimestep Vspec Tbsdf.xml Dmat.dat [ tregvec ]
DESCRIPTION
Dctimestep takes four input files, forming a matrix expression. The
first argument is the View matrix file that specifies how window output
directions are related to some set of measured values, such as an array
of illuminance points or images. This matrix is usually computed by
rtcontrib(1) for a particular set of windows or skylight openings. The
second argument is the window transmission matrix, or BSDF, given as a
standard XML description. The third argument is the Daylight matrix
file that defines how sky patches relate to input directions on the
same opening. This is usually computed using genklemsamp(1) with
rtcontrib in a separate run for each window or skylight orientation.
The final input is the sky contribution vector, usually computed by
genskyvec(1), which may be passed on the standard input. This data
must be in ASCII format, whereas the View and Daylight matrices are
more efficiently represented as binary float data if machine byte-order
is not an issue.
Sent to the standard output of dctimestep is either an ASCII color
vector with as many RGB triplets as there are rows in the View matrix,
or a combined Radiance picture. Which output is produced depends on
the Vspec argument. A regular file name will be loaded and interpreted
as a matrix to generate a color results vector. A file specification
containing a ’%d’ format string will be interpreted as a list of
Radiance component pictures, which will be summed according to the
computed vector.
EXAMPLES
To compute a set of illuminance contributions for Window 1 on the
Winter solstice at 2pm:
gensky 12 21 14 | genskyvec | dctimestep IllPts.vmx Blinds20.xml
Window1.dmx > Ill_12-21-14.dat
To compute Window2’s contribution to an interior view at 12 noon on the
Summer solstice:
gensky 6 21 12 | genskyvec | dctimestep view%03d.hdr Blinds30.xml
Window2.dmx > view_6-21-12.hdr
AUTHOR
Greg Ward
SEE ALSO
genklemsamp(1), genskyvec(1), mkillum(1), rtcontrib(1), rtrace(1),
vwrays(1)