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dctimestep(1) [minix man page]

DCTIMESTEP(1)						      General Commands Manual						     DCTIMESTEP(1)

dctimestep - compute annual simulation time-step via matrix multiplication SYNOPSIS
dctimestep DCspec [ skyvec ] dctimestep Vspec Tbsdf.xml Dmat.dat [ skyvec ] DESCRIPTION
Dctimestep has two invocation forms. In the first form, dctimestep is given a daylight coefficient specification and an optional sky vec- tor, which may be read from the standard input if unspecified. The daylight coefficients are multiplied against this vector and the results are written to the standard output. This may be a list of color values or a combined Radiance image, as explained below. In the second form, dctimestep takes four input files, forming a matrix expression. The first argument is the View matrix file that speci- fies 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 trans- mission 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 first argument. A regular file name will be loaded and inter- preted 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 workplane illuminances at 3:30pm on Feb 10th: gensky 2 10 15:30 | genskyvec | dctimestep workplaneDC.dmx > Ill_02-10-1530.dat To compute an image at 10am on the equinox from a set of component images: gensky 3 21 10 | genskyvec | dctimestep viewc%03d.hdr > view_03-21-10.hdr 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) RADIANCE
12/09/09 DCTIMESTEP(1)

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GENKLEMSAMP(1)						      General Commands Manual						    GENKLEMSAMP(1)

genklemsamp - generate ray samples over surfaces using Klems BSDF basis SYNOPSIS
genklemsamp [ -c N ][ -f{a|f|d} ] [ view opts ] [ geom.rad .. ] DESCRIPTION
Genklemsamp generates ray origins and directions to sample planar surfaces needed to determine incident radiances or daylight coefficients. This command is typically used in conjunction with rtcontrib(1) to analyze exterior daylight coefficients for an annual simulation. The view options are needed to specify (at minimum) the view direction, which corresponds to the orientation of the surfaces, and the view up vector, which corresponds to the azimuth=90-degree position on the Klems sampling hemisphere. The view fore clipping distance is also quite useful, as it provides a means to pass through some thickness in a fenestration system before samples are sent out. Other view options such as the view type and aft clipping distance are overridden or ignored. If no Radiance scene files are provided, then the specified parallel view defines the width, height, center, and orientation of the window or facade of interest. If one or more scene files are given, they are presumed to contain planar surfaces over which genklemsamp will originate samples. The sampled surface normals must correspond to the specified view direction, and unaligned surfaces are silently ignored. The -c option specifies the number of rays to sample per Klems direction. These samples will be distributed evenly over the surface(s). The default setting is 1000. The -ff option specifies that output rays should be generated as 32-bit IEEE binary float values. This may be more efficient if passed directly to rtcontrib or rtrace(1) with the same option. Likewise, the -fd option specifies 64-bit IEEE binary double values. The default setting of -fa produces ASCII floating point values. EXAMPLE
To generate 500 samples per direction over a set of south-facing windows and pass to rtcontrib to compute daylight coefficients in a matrix: genklemsamp -c 500 -vd 0 -1 0 -vu 0 0 1 south_windows.rad | rtcontrib -c 500 -e MF:1 -f -b rbin -bn Nrbins exterior.oct > Dsouth.dat AUTHOR
Greg Ward SEE ALSO
dctimestep(1), genBSDF(1), genskyvec(1), mkillum(1), rtcontrib(1), rtrace(1), vwrays(1) RADIANCE
6/13/09 GENKLEMSAMP(1)
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