Mark Chimley on Wed, 1 Aug 2001 21:26:40 +0100 (BST)

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I have been using simplify (ground (x)) to convert x (a polynomial with
complex coefficients) into one with integer coefficients. The polynomial
is an approximation to a class equation of an imaginary quadratic field,
so is known to reside in Z[X]. The problem is, when the coefficients
become suitably large, I get the error, "precision loss in truncation".
I have tried using precision (x, n) to increase the number of decimal
places in x prior to rounding, and although this seemed to overcome the
error, simplify (x) did not give a polynomial with integer coefficients.

I think an example might be appropriate to explain the problem better,
so I shall log some output. In the meantime, I shall post this message
to see if there is anything obvious that I am doing wrong, and to ask
exactly what "precision loss in truncation" means.


Mark Chimley,
Department Of Mathematics,
University Of Bristol