--- ray/doc/man/man1/pvsum.1 2025/03/27 17:03:41 1.2 +++ ray/doc/man/man1/pvsum.1 2025/05/22 21:39:42 1.4 @@ -1,4 +1,4 @@ -.\" RCSid $Id: pvsum.1,v 1.2 2025/03/27 17:03:41 greg Exp $" +.\" RCSid $Id: pvsum.1,v 1.4 2025/05/22 21:39:42 greg Exp $" .TH PVSUM 1 12/09/09 RADIANCE .SH NAME pvsum - sum component Radiance pictures based on vector or matrix @@ -64,8 +64,8 @@ option is given, all data is sent to the standard outp which may be a sequence of Radiance pictures as understood by .I ra_rgbe(1) in the case of a multi-column input matrix. -(Note that there is currently no Radiance tool that understands a -concatenated series of float or spectral pictures.)\0 +(Note that there is currently no Radiance tool that fully +handles a concatenated series of float or spectral pictures.)\0 .PP The .I \-N @@ -92,29 +92,23 @@ gensdaymtx -of sfo.epw | pvsum -o timestep%04d.hsr -N .SH NOTES This tool overlaps with .I dctimestep, -but provides some important capabilities. -First, +but provides some missing capabilities. +Foremost, .I pvsum reads and can produce spectral pictures and matrices, whereas .I dctimestep expects and requires 3-component pictures and matrices throughout. -Changing the data structures in -.I dctimestep -proved too difficult and likely to -lead to a less efficient implementation, especially on systems with -limited memory. -In contrast, +In addition, .I pvsum accelerates picture sums on Unix systems with more -memory and processint ability. -Second, operation was simplified by focusing on the Daylight Coefficient +memory and CPU cores. +Operations were simplified by focusing on the Daylight Coefficient command form, where the DC matrix is represented as a collection of pictures. -By excluding the other operation modes of -.I dctimestep, -new functionality could be explored and optimized, -such as floating-point support and -sending output to commands as well as files. +Finally, +.I pvsum +offers more flexible floating-point support and +can output to commands as well as files. .SH AUTHOR Greg Ward .SH "SEE ALSO"