Abstract : Several different techniques and softwares intend to improve the accuracy of results
computed in a fixed finite precision. Here we focus on methods to improve the accuracy
of summation, dot product and polynomial evaluation. Such algorithms exist real floating
point numbers. In this paper, we provide new algorithms which deal with complex floating
point numbers. We show that the computed results are as accurate as if computed in
twice the working precision. The algorithms are simple since they only require addition
subtraction and multiplication of floating point numbers in the same working precision as
the given data.