== Masked data output ==
=== General ===
From release 3.7a (r483) output of masked data is implemented in PALM. This feature allows to output quantities at different mask locations, e.g. 3d volume data or 2d cross sections of arbitrary extension within the model domain; 0d or 1d data at any positions and of any amount.\\
NetCDF4 file format is already available for masked data output.\\
Default quantities (instantaneous and time averaged) can be declared with the parameter [../d3par#data_output_masks data_output_masks], user-defined quantities can be output with [../userpar#data_output_masks_user data_output_masks_user].\\\\
=== Output steering ===
Different [../d3par runtime parameters] defines the masks and steers the output of the quantities assigned with [../d3par#data_output_masks data_output_masks] and/or [../userpar#data_output_masks_user data_output_masks_user]:
   [../d3par#dt_domask dt_domask]\\
   [../d3par#mask_scale_x mask_scale_x]\\
   [../d3par#mask_scale_y mask_scale_y]\\
   [../d3par#mask_scale_z mask_scale_z]\\
   [../d3par#mask_x mask_x]\\
   [../d3par#mask_y mask_y]\\
   [../d3par#mask_z mask_z]\\
   [../d3par#mask_x_loop mask_x_loop]\\
   [../d3par#mask_y_loop mask_y_loop]\\
   [../d3par#mask_z_loop mask_z_loop]\\
   [../d3par#skip_time_domask skip_time_domask]
So far 20 different masks can be defined. Each mask is output to one local file.\\\\
Instantaneous data of '''mask 1''' are output to file [../iofiles#DATA_MASK_01_NETCDF DATA_MASK_01_NETCDF], time-averaged data to file [../iofiles#DATA_MASK_01_AV_NETCDF DATA_MASK_01_AV_NETCDF].\\
Instantaneous data of '''mask 2''' are output to file [../iofiles#DATA_MASK_02_NETCDF DATA_MASK_02_NETCDF], time-averaged data to file [../iofiles#DATA_MASK_02_AV_NETCDF DATA_MASK_02_AV_NETCDF].\\
Instantaneous data of '''mask 3''' are output to file [../iofiles#DATA_MASK_02_NETCDF DATA_MASK_03_NETCDF], time-averaged data to file [../iofiles#DATA_MASK_02_AV_NETCDF DATA_MASK_03_AV_NETCDF].\\\\
Besides assigning the parameters listed above, the required output files have to be comment out in the '''mrun'''-[../configexample configuration file]:
{{{
#----------------------------------------------------------------------------
# List of output-files
#----------------------------------------------------------------------------
DATA_MASK_01_NETCDF       out:loc      ma#:maf         $output_data      _m01     nc
DATA_MASK_01_AV_NETCDF    out:loc      ma#:maf         $output_data      _m01_av  nc
DATA_MASK_02_NETCDF       out:loc      ma#:maf         $output_data      _m02     nc
DATA_MASK_02_AV_NETCDF    out:loc      ma#:maf         $output_data      _m02_av  nc
#DATA_MASK_03_NETCDF       out:loc      ma#:maf         $output_data      _m03     nc
#DATA_MASK_03_AV_NETCDF    out:loc      ma#:maf         $output_data      _m03_av  nc
...
#DATA_MASK_20_NETCDF       out:loc      ma#:maf         $output_data      _m20     nc
#DATA_MASK_20_AV_NETCDF    out:loc      ma#:maf         $output_data      _m20_av  nc
}}}
Here output of masks 1 and 2 is done. Masks 3 to 20 will not be output even if the parameters are assigned.\\\\
Within the '''mrun''' call ''ma#'' has to be added to the '''mrun'''-option -r:
{{{
mrun -d example_cbl -h... -r "d3# ma#"
}}} 
\\
=== Examples ===