#1719: GRASS 7 Monitor command line support -------------------------+-------------------------------------------------- Reporter: annalisapg | Owner: grass-dev@… Type: enhancement | Status: new Priority: normal | Milestone: 7.0.0 Component: wxGUI | Version: svn-trunk Keywords: d.mon | Platform: Unspecified Cpu: Unspecified | -------------------------+--------------------------------------------------
Comment(by glynn): Replying to [comment:13 wenzeslaus]: > Files are much smaller The downside of this is that the d.* command will take longer as it has to compress the output file. > and there is one file less If desired, we could have a single file without the compression overhead by using the PNG writer from lib/pngdriver, which allows the compression level to be set via the GRASS_PNG_COMPRESSION environment variable. > (thanks to composing in Python) but during zooming/panning the most of the time is spent with disk IO. (Tested on Ubuntu 10.04.) Zooming and panning require re-executing the d.* commands to generate new images. > But we can output binary data to stdout and read them in Python directly. This would avoid disk IO. What do you think about using stdout instead of a file in case of d.* modules? That requires either storing all layers in memory, regardless of whether or not they are displayed, or re-generating layers if they are disabled then re-enabled. It also eliminates the possibility of implementing a decent caching mechanism (i.e. being able to undo zoom/pan operations by re-using the previous images rather than having to re-generate them). And using pipes may be slower than disk (if the Python side is using select(), there will be a context switch for each pipe-buffer-size of data). -- Ticket URL: <https://trac.osgeo.org/grass/ticket/1719#comment:14> GRASS GIS <http://grass.osgeo.org> _______________________________________________ grass-dev mailing list grass-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/grass-dev