@BeginModule
@NewPage
@Name      = Setbox
@Title     = Set a box to constant
@Section   = Modification
@Class     = Modification
@Arguments = ifile ofile
@Operators = setclonlatbox setcindexbox

@BeginDescription
Sets a box of the rectangular understood field to a constant value. 
The elements outside the box are untouched, the elements inside are 
set to the given constant. All input fields must have the same 
horizontal grid.
@EndDescription
@EndModule


@BeginOperator_setclonlatbox
@Title     = Set a longitude/latitude box to constant
@Parameter = c lon1 lon2 lat1 lat2

@BeginDescription
Sets the values of a longitude/latitude box to a constant value. The 
user has to give the longitudes and latitudes of the edges of the box.
@EndDescription
@EndOperator


@BeginOperator_setcindexbox
@Title     = Set an index box to constant
@Parameter = c idx1 idx2 idy1 idy2

@BeginDescription
Sets the values of an index box to a constant value. The user has to 
give the indexes of the edges of the box. The index of the left edge 
may be greater then that of the right edge.
@EndDescription
@EndOperator


@BeginParameter idx1
@Item = c
FLOAT    Constant
@Item = lon1
FLOAT    Western longitude
@Item = lon2
FLOAT    Eastern longitude
@Item = lat1
FLOAT    Southern or northern latitude
@Item = lat2
FLOAT    Northern or southern latitude
@Item = idx1
INTEGER  Index of first longitude
@Item = idx2
INTEGER  Index of last longitude
@Item = idy1
INTEGER  Index of first latitude
@Item = idy2
INTEGER  Index of last latitude
@EndParameter


@BeginExample
To set all values in the region with the longitudes from 120E to 90W and
latitudes from 20N to 20S to the constant value -1.23, use:
@BeginVerbatim
   cdo setclonlatbox,-1.23,120,-90,20,-20 ifile ofile
@EndVerbatim
If the input dataset has fields on a T21 gaussian grid, the same box can
be set with @oper{setcindexbox} by:
@BeginVerbatim
   cdo setcindexbox,-1.23,23,48,13,20 ifile ofile
@EndVerbatim
@EndExample
