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The mask condition has the syntax mask_var mask_comp mask_val. The preferred method to specify the mask condition is in one string with the `-B' or `--mask_condition' switches. The older method is to use the three switches `-m', `-T', and `-M' to specify the mask_var, mask_comp, and mask_val, respectively. 1. The mask_condition string is automatically parsed into its three constituents mask_var, mask_comp, and mask_val.
Here mask_var is the name of the masking variable (specified with `-m', `--mask-variable', `--mask_variable', `--msk_nm', or `--msk_var'). The truth mask_comp argument (specified with `-T', `--mask_comparator', `--msk_cmp_typ', or `--op_rlt' may be any one of the six arithmetic comparators: eq, ne, gt, lt, ge, le.
These are the Fortran-style character abbreviations for the logical comparisons ==, !=, >, <, >=, <=.
The mask comparator defaults to eq (equality). The mask_val argument to `-M' (or `--mask-value', or `--msk_val') is the right hand side of the mask condition. Thus for the i'th element of the hyperslab to be averaged, the mask condition is
mask(i) mask_comp mask_val.
[1] The three switches `-m', `-T', and `-M' are maintained for backward compatibility and may be deprecated in the future. It is safest to write scripts using `--mask_condition'.