technicalsouce9 asked . 2021-01-14

How can I apply sgolay derivatives to a matrix of signals

• Does it make sense to rework this to a matrix operation?
• Can someone help me with the re-work of the code? I am absolutely lost..

function [derivatives] = JF_savitzky_derivative(spectra, order, framelen, returnorder)

    % create return data array
      derivatives = spectra;
      derivatives(:,:) = 0;

    % define input
      sizes       = size(spectra);
      numspectra  = sizes(1);
      numbands    = sizes(2);

    % Create the filter
      [b,g] = sgolay(order,framelen);

    % create the temporary valuestore
      dx = zeros(numbands,returnorder+1);

    % Set the spacing between measurements
      dt = 1;

    % for each spectrum run the filter
      for spectrum = 1:length(spectra(:,1))

        x=spectra(spectrum,:);

        for p = 0:returnorder
          dx(:,p+1) = conv(x, factorial(p)/(-dt)^p * g(:,p+1), 'same');
        end

        derivatives(spectrum,:) = dx(:,returnorder+1);

      end

    end

matlab , signal , signal processing , matrix