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D.6 gslevu

This library exports a pair of functions of the form

     library('gslevu','accel')
     
     library('gslevu','utrunc')

that take a list of real numbers x to a pair of real numbers (s,e).

The idea is that x represents the first few terms of an infinite series whose sum converges, but only very slowly. The functions extrapolate an estimate of the infinite summation by the Levin u-transform as documented in the GNU Scientific Library reference manual.

For well behaved series, considerably fewer terms are needed for an accurate estimate than a direct summation would require.