  In this paper, we study the error behavior of the nonequispaced fast Fourier
transform (NFFT). This approximate algorithm is mainly based on the convenient
choice of a compactly supported window function. Here we consider the
continuous Kaiser--Bessel, continuous $\exp$-type, $\sinh$-type, and continuous
$\cosh$-type window functions with the same support and same shape parameter.
We present novel explicit error estimates for NFFT with such a window function
and derive rules for the optimal choice of the parameters involved in NFFT. The
error constant of a window function depends mainly on the oversampling factor
and the truncation parameter. For the considered continuous window functions,
the error constants have an exponential decay with respect to the truncation
parameter.
