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.TH DCGLARE |
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.SH NAME |
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dcglare - compute glare in annual simulation time-step(s) via matrix |
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multiplication |
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.SH SYNOPSIS |
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.B dcglare |
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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 "\-i{f|d} |
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][ |
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.B "\-o{f|d} |
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][ |
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.B "\-l |
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.I val |
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][ |
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.B "\-b |
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.I val |
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][{ |
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.B "\-sf |
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.I file |
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| |
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.B "\-ss |
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.I h |
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.B "\-so |
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.I h |
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}][ |
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.B "\-vu |
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.I dx dy dz |
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]{ |
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.B "\-vd |
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.I dx dy dz |
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| |
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.B "\-vf |
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.I file |
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[ |
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.B "\-vi{f|d} |
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]} |
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.B DCdirect |
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.B DCtotal |
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[ |
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.B skyf |
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] |
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.br |
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.B dcglare |
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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 "\-i{f|d} |
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][ |
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.B "\-o{f|d} |
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][ |
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.B "\-l |
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.I val |
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][ |
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.B "\-b |
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.I val |
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][{ |
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.B "\-sf |
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.I file |
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| |
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.B "\-ss |
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.I h |
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.B "\-so |
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.I h |
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}][ |
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.B "\-vu |
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.I dx dy dz |
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]{ |
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.B "\-vd |
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.I dx dy dz |
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| |
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.B "\-vf |
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.I file |
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[ |
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.B "\-vi{f|d} |
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]} |
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.B DCdirect |
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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 Dcglare |
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generates daylight glare probability (DGP) predictions for multiple points in a |
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space under a variety of daylit conditions. Usually, it is used to produce |
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hourly DGP values for an entire year, or if the |
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.I \-l |
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option is provided, it calculates glare autonomy based on an annual occupancy |
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schedule. |
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.PP |
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As input, |
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.I dcglare |
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requires daylight coefficient matrices relating the illuminance at each view |
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point to the brightness of each sky patch. Two such matrices are required. |
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The first, |
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.I DCdirect |
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, consists of direct views to the sky only and is calculated by |
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.I rcontrib(1) |
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using a single ambient bounce. The second, |
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.I DCtotal |
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, includes the total direct and diffuse contribution of each sky patch. |
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The latter can be calculated directly by |
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.I rcontrib(1) |
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as in the two-phase method, or internally as in the three-phase method if given |
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view, BSDF, and daylight matrices. In this respect, |
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.I dcglare |
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is similar to |
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.I dctimestep(1) |
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except that it calculates DGP instead of irradiance. |
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The final input is the sky contribution matrix, usually computed by |
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.I gendaymtx(1) |
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, which may be passed on the standard input. |
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For efficiency, matrices stored in files can be represented as binary float data |
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if machine byte-order is not an issue. |
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.PP |
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In the imageless method for calculating DGP, each visible sky patch acts |
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as a glare source if it's brightness is above a threshold set by the |
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.I \-b |
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option. This option behaves similarly to the option in |
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.I evalglare(1) |
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as described below. |
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Imageless DGP calculation also requires that the view direction must be |
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specified for each view to orient it relative to the given sky patches. |
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If all views are oriented in the same direction, |
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.I \-vd |
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can be used to specify the view direction vector. |
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Alternatively, a view file can be specified by the |
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.I \-vf |
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option. The format for this file is the same as the input format expected by |
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.I rcontrib(1) |
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, and for simplicity, the same file can be provided as input to both programs. |
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The |
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.I \-vif |
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or |
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.I \-vid |
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option may be used to specify that view data is in float or double format, |
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respectively. |
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The up vector |
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.I \-vu |
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is used together with the direction vector to calculate the Guth index for each |
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sky patch relative to each view. |
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While each entry in the view file may have a unique view direction, a single up |
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vector is used for all views. The default up vector is in the positive |
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.I z |
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direction. |
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.PP |
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Glare autonomy refers to the fraction of occupied hours in which a view is free |
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of glare. When a glare limit is specified with the |
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.I \-l |
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option, |
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.I dcglare |
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will calculate the fraction of sky conditions from the sky matrix in which DGP |
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is less than this limit. In this case, individual DGP values are not recorded. |
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By default, all entries in the sky matrix are included in the glare autonomy |
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calculation, unless limitted by the |
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.I \-n |
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option. |
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However, you may exclude certain entries by creating an occupancy schedule. |
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This is useful if the sky matrix built with |
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.I gendaymtx(1) |
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contains all hours of a year, but the space will only be occupied at certain |
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times. You may specify an occupancy schedule file with the |
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.I \-sf |
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option. This file should be in comma-separated value format with the same number |
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of rows as in the sky matrix. The last entry of each line is read as a numeric |
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value that should be greater than zero for occupied times. Lines may be |
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commented with a '#' character. |
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This format is compatible with Daysim schedule files. |
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Alternatively, if the sky matrix contains 24 entries per day corresponding to |
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one per hour, uniform daily start and end hours for occupancy can be specified |
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with the |
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.I \-ss |
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and |
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.I \-se |
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options. No adjustment is made for daylight savings time. |
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.PP |
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In addition to these, you may specify options from |
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.I dctimestep(1) |
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with the exception of |
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.I \-o |
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because image rendering is not supported. |
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.TP 12n |
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.BI -l \ val |
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Set the limit for glare occurrence to |
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.I val |
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\&. When this option is provided, the program calculates glare autonomy, |
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where any DGP value at or above the limit |
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.I val |
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indicates the presence of glare. If the option is not provided, the program |
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calculates DGP under each sky condition in the sky matrix instead. |
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.TP |
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.BI -b \ val |
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Set the threshold factor to |
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.I val |
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\&. If |
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.I val |
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is larger than 100, it is used as constant threshold in cd/m2. If |
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.I val |
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is less or equal than 100, this factor multiplied by the average luminance in |
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each view will be used as threshold for detecting the glare sources (not |
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recommended). The default value is 2000 (fixed threshold method). |
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.TP |
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.BI -vf \ file |
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Get the list of views for DGP calculation from |
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.I file |
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\&. Each line in |
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.I file |
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contains six numeric values corresponding to the position and direction |
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of a view. Generally, this is the same file that is used as input to |
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.I rcontrib(1) |
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to create the daylight coefficient matrices |
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.TP |
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.BI -vd " xd yd zd" |
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Set the view forward vector (vertical direction) for DGP calculation to |
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.I xd yd zd |
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\&. This option is ignored when the |
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.I \-vf |
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option is provided. |
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.TP |
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.BI -vu " xd yd zd" |
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Set the view up vector (vertical direction) for DGP calculation to |
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.I xd yd zd |
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\&. The default up vector is the positive |
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.I z |
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direction. |
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.TP |
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.BI -vi t |
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Set the format of the view file to |
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.I t |
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\&. Available options are 'f' for single and 'd' for double precison IEEE float. |
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The default when no value is provided is to use ASCII. |
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.TP |
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.BI -sf \ file |
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Set the occupancy schedule file to |
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.I file |
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\&. In the event that the sky matrix includes unoccupied hours that should not |
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contribute to the glare autonomy calculation, |
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.I file |
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will be read to determine which entries from the sky file matrix will be |
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included in this calculation. Each line of |
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.I file |
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is expected to contain a numeric value at the end of a comma-delimited list, |
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with zero corresponding to unoccupied. |
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This argument is used only if |
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.I -l |
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is specified. |
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.TP |
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.BI -ss \ h |
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Set the occupancy start hour to |
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.I h |
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\&. This option is provided for expediency when no occupancy schedule file is |
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available. It is assumed that the sky matrix includes 24 entries per day, |
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corresponding to one per hour. This argument is used only if |
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.I -l |
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is specified. |
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.TP |
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.BI -se \ h |
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Set the occupancy end hour to |
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.I h |
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\&. This option is provided for expediency when no occupancy schedule file is |
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available. It is assumed that the sky matrix includes 24 entries per day, |
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corresponding to one per hour. This argument is used only if |
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.I -l |
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is specified. |
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.SH EXAMPLES |
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To generate an hourly matrix of DGP where output columns are time steps and rows |
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correspond to views in the file views.vf: |
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.IP "" .2i |
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gendaymtx -of Tampa.wea > sky.smx |
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.IP "" .2i |
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rcontrib -e MF:1 -f reinhartb.cal -b rbin -bn Nrbins -m sky_mat -I+ -ab 1 |
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-ad 50000 -lw .00002 -lr -10 -faf scene.oct < views.vf > dc1.mtx |
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.IP "" .2i |
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rcontrib -e MF:1 -f reinhartb.cal -b rbin -bn Nrbins -m sky_mat -I+ -ab 8 |
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-ad 50000 -lw .00002 -lr -10 -faf scene.oct < views.vf > dc8.mtx |
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.IP "" .2i |
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dcglare -vf views.vf dc1.mtx dc8.mtx sky.smx > dgp.txt |
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.PP |
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To calculate glare autonomy based on a 40% DGP limit using the same matrices: |
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.IP "" .2i |
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dcglare -vf views.vf -sf 8to6withDST.60min.occ.csv -l .4 dc1.mtx dc8.mtx |
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sky.smx > ga.txt |
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.PP |
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To generate an hourly matrix of DGP values from Skylight3 using a 3-phase |
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calculation, where output columns are time steps: |
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.IP "" .2i |
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gendaymtx NYCity.wea | dcglare dc1.mtx WPpts.vmx shade3.xml Skylight3.dmx |
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> wp_win3.dat |
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.SH AUTHOR |
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Nathaniel Jones |
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.SH SEE ALSO |
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dctimestep(1), gendaymtx(1), rcontrib(1), evalglare(1) |