Changes in version 2.0 (2021-03-29)                   

    o   add summary() and print() functions

    o   add deconvolve() function to perform analytically deconvolution

    o   add standardized PSD and false alarm probability to spec.fft-function

    o   spec.fft handles NA-values by zero padding and simple energy recovery.

    o   enhance calculation speed by multithreaded BLAS (must be replaced by user)

    o   add 1D FFT interpolation function

    o   read out cache size for memory usage in spec.lomb

    o   bug fix memory calculation in spec.lomb()

    o   bug fix single frequency in spec.lomb()

    o   optional cluster (hpc) calculation in spec.lomb()

    o   adding a progressbar to spec.lomb()

    o   waterfall() calculates PSD as well

    o   changed variable band width in waterfall()

    o   waterfall also ignores NA values and corrects

    o   adding progress bar to waterfall()

    o   extending band pass function BP() by sinc, bi-cubic and gauss kernels

    o   modified all dependend functions which use band pass BP()

    o   add Hanning window function

                        Changes in version 1.3.1                        

    o   spec.lomb: phase value at f = 0 -> 0

                  Changes in version 1.3 (2019-06-03)                   

    o   improved documentation

    o   FFT as well as any LOMB version work with *multivariate* input

    o   Added generalized Lomb-Scargle method

    o   improved speed of both the normal Lomb-Scargle Method and generalized Lomb

    o   power spectral density is now normalized to sample variance

    o   limit memory usage

                  Changes in version 1.0 (2016-09-13)                   

    o   development of all functions

    o   development of concepts