Patent ID: 7895002

Claim:
A device comprising; a sensor arrangement for providing first field information defining at least a part of a first field, the part of the first field comprising respective first and second components of the first field in respective first and second directions and a third component of the first field in a third direction, and for providing second field information defining at least a part of a second field, the part of the second field comprising respective first and second components of the second field in respective first and second directions, and an updater for updating at least a parameter of at least one of the first and second fields via at least one criterion-dependent iteration, the parameter comprising a magnitude of at least one of the first and second fields and a dot product of the first and second fields, the criterion-dependent iteration comprising a magnitude function and a dot product function, wherein the magnitude function defining a new magnitude of the second field being a function of an old magnitude of the second field and of an updated magnitude of the second field and the dot product function defining a new dot product of the first and second fields being a function of an old dot product of the first and second fields and of an updated dot product of the first and second fields.