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.\" RCSid $Id: dctimestep.1,v 1.15 2019/03/01 01:00:03 greg Exp $" |
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.TH DCTIMESTEP 1 12/09/09 RADIANCE |
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.SH NAME |
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dctimestep - compute annual simulation time-step(s) via matrix multiplication |
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.SH SYNOPSIS |
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.B dctimestep |
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[ |
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.B "\-n nsteps" |
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][ |
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.B "\-h" |
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][ |
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.B "\-o ospec" |
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][ |
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.B "\-i{f|d} |
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][ |
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.B "\-o{f|d|c} |
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] |
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.B DCspec |
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[ |
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.B skyf |
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] |
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.br |
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.B dctimestep |
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[ |
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.B "\-n nsteps" |
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][ |
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.B "\-h" |
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][ |
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.B "\-o ospec" |
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][ |
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.B "\-i{f|d} |
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][ |
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.B "\-o{f|d} |
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] |
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.B Vspec |
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.B Tbsdf |
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.B Dmat.dat |
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[ |
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.B skyf |
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] |
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.SH DESCRIPTION |
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.I Dctimestep |
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has two invocation forms. |
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In the first form, |
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.I dctimestep |
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is given a daylight coefficient specification and an optional sky |
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vector or matrix, which may be read from the standard input if unspecified. |
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The daylight coefficients are multiplied against these sky values |
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and the results are written to the standard output. |
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This may be a list of color values or a combined Radiance image, |
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as explained below. |
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.PP |
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In the second form, |
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.I dctimestep |
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takes four input files, forming a matrix expression. |
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The first argument is the View matrix file that specifies how window output |
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directions are related to some set of measured values, such as an array of |
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illuminance points or images. |
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This matrix is usually computed by |
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.I rfluxmtx(1) |
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or |
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.I rcontrib(1) |
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for a particular set of windows or skylight openings. |
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The second argument is the window transmission matrix, or BSDF, given as |
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a matrix or a standard XML description. |
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The third argument is the Daylight matrix file that defines how sky patches |
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relate to input directions on the same opening. |
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This is usually computed using |
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.I rfluxmtx |
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with separate runs for each window or skylight orientation. |
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The last file is the sky contribution vector or matrix, |
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typically computed by |
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.I genskyvec(1) |
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or |
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.I gendaymtx(1), |
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and may be passed on the standard input. |
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.PP |
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If the input sky data lacks a header, the |
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.I \-n |
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option may be used to indicate the number of time steps, which |
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will be 1 for a sky vector. |
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The sky input file must otherwise contain the number of |
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columns (time steps) specified in each sky patch row, |
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whether it is read from the standard input or from a file. |
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Input starts from the first patch at the first time step, then the |
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first patch at the second time step, and so on. |
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Note that all matrix elements are RGB triplets, so the actual size |
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of the sky vector or matrix is three times the number of steps times |
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the number of sky patches. |
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The |
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.I \-if |
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or |
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.I \-id |
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option may be used to specify that sky data is in float or double |
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format, respectively, which is more efficient for large matrices. |
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These options are unnecessary when the sky input includes a header. |
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.PP |
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Any of the matrix or vector files may be read from a command |
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instead of a file by |
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using quotes and a beginning exclamation point ('!'). |
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.PP |
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The standard output of |
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.I dctimestep |
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is either a color vector with as many RGB triplets |
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as there are rows in the View matrix, or a combined |
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.I Radiance |
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picture. |
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Which output is produced depends on the first argument. |
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A regular file name will be loaded and interpreted as a matrix to |
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generate a color results vector. |
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A file specification containing a '%d' format string will be |
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interpreted as a list of |
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.I Radiance |
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component pictures, which will be summed according to the computed |
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vector. |
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.PP |
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The |
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.I \-o |
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option may be used to specify a file or a set of output files |
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to use rather than the standard output. |
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If the given specification contains a '%d' format string, this |
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will be replaced by the time step index, starting from 0. |
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In this way, multiple output pictures may be produced, |
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or separate result vectors (one per time step). |
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.PP |
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A header will normally be produced on the output, unless the |
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.I \-h |
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option is specified. |
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The |
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.I \-of, |
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.I \-od, |
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or |
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.I \-oc |
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option may be used to specify IEEE float, double, or RGBE (picture) output |
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data, respectively. |
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.SH EXAMPLES |
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To compute workplane illuminances at 3:30pm on Feb 10th: |
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.IP "" .2i |
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gensky 2 10 15:30 | genskyvec | dctimestep workplaneDC.dmx > Ill_02-10-1530.dat |
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.PP |
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To compute an image at 10am on the equinox from a set of component images: |
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.IP "" .2i |
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gensky 3 21 10 | genskyvec | dctimestep dcomp%03d.hdr > view_03-21-10.hdr |
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.PP |
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To compute a set of illuminance contributions for Window 1 on |
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the Winter solstice at 2pm: |
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.IP "" .2i |
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gensky 12 21 14 | genskyvec | dctimestep IllPts.vmx Blinds20.xml Window1.dmx > Ill_12-21-14.dat |
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.PP |
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To compute Window2's contribution to an interior view at 12 noon on the Summer solstice: |
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.IP "" .2i |
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gensky 6 21 12 | genskyvec | dctimestep view%03d.hdr Blinds30.xml |
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Window2.dmx > view_6-21-12.hdr |
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.PP |
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To generate an hourly matrix of sensor value contributions from Skylight3 |
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using a 3-phase calculation, where output columns are time steps: |
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.IP "" .2i |
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gendaymtx -of Tampa.wea | dctimestep WPpts.vmx |
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shade3.xml Skylight3.dmx > wp_win3.dat |
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.PP |
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Generate a series of pictures corresponding to timesteps |
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in an annual simulation: |
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.IP "" .2i |
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gendaymtx NYCity.wea | dctimestep -o tstep%04d.hdr dcomp%03d.hdr |
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.PP |
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To multiply an irradiance view matrix through a pair of XML window layers using |
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a given exterior daylight matrix and sky vector: |
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.IP "" .2i |
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dctimestep Illum.vmx "!rmtxop -ff Blinds1.xml Windo1.xml" Exter.dmx Jan20.sky |
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.PP |
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To multiply two matrices into a IEEE-float result with header: |
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.IP "" .2i |
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dctimestep -of Inp1.fmx Inp2.fmx > Inp1xInp2.fmx |
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.SH AUTHOR |
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Greg Ward |
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.SH "SEE ALSO" |
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gendaymtx(1), genskyvec(1), getinfo(1), |
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mkillum(1), rcollate(1), rcontrib(1), |
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rfluxmtx(1), rmtxop(1), rtrace(1), vwrays(1) |