Gerris Manual/Object hierarchy/GfsOutput

This generic object is a ../GfsEvent/ which also defines where to write the data to output. The syntax in parameter files is as follows: [ ../GfsEvent/ ] FILE where FILE is either a string defining the file in which to write the output, or a shell-script enclosed within braces to which the output will be piped. Two file names have special meaning: "stderr" and "stdout" for the standard error and standard output respectively. If a C-like formatting string appears in the file name, it is interpreted as follows: %d is replaced with the current processor number. %ld is replaced with the current time step number. %f is replaced with the current physical time. Note that most of the C language format specifiers are recognized (i.e. it is possible to use formatting strings like %05.2f etc...). If the simulation does not start at time zero the existing files are appended otherwise they are overwritten. The "pipe" feature of GfsOutput can for example be used to do on-the-flight post-processing of the data stream, as in the following example: GfsOutputPPM { istep = 1 } { ppmtoy4m -v 0 -F 24:1 | mpeg2enc -v 0 -o vorticity.mpg } { v = Vorticity } which will convert the PPM stream generated by GfsOutputPPM directly to MPEG using the MJPEG tools collection. open source software