search for: wavenumber

I have a matrix named "spec" (see below), it is a 6x3 matrix, and each element of spec is a list. For example, spec[1,"wavenumber"] is a list, and it contains 1876 numeric numbers and NAs. I want to replace the NAs to zero, but don't know how to change it, the difficulty may be all the elements are of the class list, so it is hard to change. Thank you for your help! matrix spec: wavenumber prescan po...

Hi I need to compute the fft of an image A with dimension (Nx,Ny) and are not sure on how to compute the wavenumber. I have done like that but i am not sure i am computing the wavenumber in the correct way..can someone help? sara image.plot(x,y,A) dx = diff(x)[1] dy = diff(y)[1]      ## This is equivalent to what the matlab fftshift function does fzs = fft(A) Fzs  = fftshift2D(fzs)/(Nx*Ny); ## compute...

Hi all, I 've got a question about the usage of loess in the modreg package. The documentation (loess.html) states that the smoothing window is either set by span or enp.target. If span is used, the details section of the docs state... <SNIP> DETAILS Fitting is done locally. That is, for the fit at point x, the fit is made using points in a neighbourhood of x, weighted by their

Hi all, I 've got a question about the usage of loess in the modreg package. The documentation (loess.html) states that the smoothing window is either set by span or enp.target. If span is used, the details section of the docs state... <SNIP> DETAILS Fitting is done locally. That is, for the fit at point x, the fit is made using points in a neighbourhood of x, weighted by their