Function File: irsa_actcore.m

[rfyp,err] = irsa_actcore (xpn, yp, fmaxn, [itmax], [thresh])

Reconstruction of the frequency representation (i.e. the spectrum) of a band-limited signal from an irregular sampled timeseries using Adaptive weights, Conjugate gradients and Toeplitz matrices.

Input:

xpn : Vector – sampling points in [0,(N-1)/N]

yp : Vector – corresponding sampling values

fmaxn : Scalar – maximum (band-limiting) frequency. Due to the scaling of xpn it has to be a positive integer.

itmax : Scalar – maximum number of reconstruction iterations. Default is twice the number of the frequencies.

thresh: Scalar – threshold for conjugate gradients (stop criterion). Default is machine precision.

Output:

rfyp : Columnvector – reconstructed spectrum

err : Columnvector – error for each iteration step

Note:

The use of this function requires normalized sampling points xpn in [0,(N-1)/N] and the knowledge of fmaxn. Use the function irsa_normalize for this task.