PL/pgsql function handle CUBE values

Hi, I am trying to write a PL/pgsql function that will take a CUBE
variable (which will be a 1D point) and a double precision variable.

If the input CUBE is defined as

'(x,y,z)'::cube

the function would then return a CUBE value of the form

'(x+R,y+R,z+R),(x-R,y-R,z-R)'::cube

where R is the second argument.

The problem I'm having is to actually add R to the individual
components of the CUBE variable. I can't cast CUBE to float[] and I
don't see anyway to get at the individual components of the CUBE.

Any pointers would be appreciated.

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Rajarshi Guha  <rguha@indiana.edu>
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"355/113 -- Not the famous irrational number PI,
but an incredible simulation!"