cdfthresh −− thresholds variable fields
cdfthresh ’var_name < value’ ...
cdfthresh ’var_name > value’ ...
cdfthresh ’var_name < badlim’ ...
cdfthresh ’var_name > badlim’ ...
Cdfthresh reads a common data format file on the standard input and writes a modified file to the standard output. The modification consists of setting certain variable field elements to the bad data value. Variable fields are considered in groups defined over the same space, i. e., with the same dimension names. If a field belonging to a particular group is indicated on the command line, then it becomes a threshold field for that group. For example, if ’w > 5’ is specified, then every element in the w field which is less than or equal to 5 is set to the bad data value. Furthermore, elements of all fields belonging to the same group are set to bad if the corresponding w element doesn’t satisfy the command line condition. If the word "badlim" is substituted for the value, the threshold condition is either "data good" or "data bad", depending on whether the operator is "<" or ">". Multiple command line arguments cause thresholding operations to be applied successively.
kestrel% cdfthresh ’dbz > 0’ < input_file > output_file
In this example, all fields in the same group as dbz would be set to the bad data value where dbz doesn’t exceed zero.
kestrel% cdfthresh ’dbz < badlim’ < input_file > output_file
In this case all fields in the same group as dbz would be set to the bad data value where dbz itself is bad.