The cf.masked constant allows data array values to be masked by direct assignment. This is consistent with the behaviour of numpy masked arrays.
For example, masking every element of a field’s data array could be done as follows:
>>> f.subspace[...] = cf.masked
To mask every element of a field’s data array whose value is less than zero:
>>> f.where(cf.lt(0), cf.masked, i=True)
See also