grad {coloredICA}  R Documentation 
This function evaluates the gradient of the objective function for the spectral density local maximum likelihood estimator.
grad(x, omega, l_period, n, freq, h)
x 
Current estimate 
omega 
Frequency at which the spectral density estimate is evaluated. 
l_period 
Vector of length 
n 
Number of points in the analyzed lattice. 
freq 

h 
Kernel bandwidth. 
In scICA
function the maximization for the spectral density local maximum likelihood estimator is obtained through the NewtonRaphson algorithm. This function returns the gradient needed in the optimization method. See locmulti
for further details.
It returns a gradient vector of length 3.
It is auxiliary for scICA
function.
Lee, S., Shen, H., Truong, Y. and Zanini, P.