% phase = getProbeFreq(opt, nPrb)
%   returns the demodulation frequency of a probe or collection of probes
%
% Example:
% opt = optFP;
% getProbeFreq(opt, 'REFL_I')
% getProbeFreq(opt, {'REFL_I', 'REFL_Q'})
% getProbeFreq(opt)


function phase = getProbeFreq(opt, varargin)

  if isempty(varargin)
    sn = 1:opt.Nprobe;
  else
    sn = varargin{1};
  end

  if ischar(sn) || length(sn) == 1
    % a single number or name
    sn = getProbeNum(opt, sn);
    phase = opt.probe(sn).freq;
  elseif iscell(sn)
    % a cell array of numbers or names
    N = length(sn);
    phase = zeros(N, 1);
    for n = 1:N
      snn = getProbeNum(opt, sn{n});
      phase(n) = opt.probe(snn).freq;
    end
  else
    % an vector of numbers
    N = length(sn);
    phase = zeros(N, 1);
    for n = 1:N
      snn = getProbeNum(opt, sn(n));
      phase(n) = opt.probe(snn).freq;
    end
  end