关于disp_hhs的几个疑问

marry0539

function disp_hhs(varargin)

error(nargchk(1,3,nargin));

fs = 0;           此处的fs为什么等于0？

inf = -20;

im = varargin{1};

t = 1:size(im,2);

switch nargin

case 1

%raf  这是什么意思？

case 2

if isscalar(varargin{2})

inf = varargin{2};

else

t = varargin{2};

end

case 3

if isvector(varargin{2})

t = varargin{2};

inf = varargin{3};

else

inf = varargin{2};

fs = varargin{3};

end

case 4

t = varargin{2};

inf = varargin{3};

fs = varargin{4};

end

if isempty(inf)
%确定数组是否为空，若为空返回逻辑1，

inf = -20;

end

if inf > 0

inf = -inf;

elseif inf == 0

error('inf must be nonzero')

end

M=max(max(im));

warning off

im = 10*log10(im/M);

warning on

figure

if fs == 0   为什么等于0？

imagesc(t,[0,0.5],im,[inf,0]);

ylabel('normalized frequency')

else

imagesc(t,[0,0.5*fs],im,[inf,0]);

ylabel('frequency')

end

set(gca,'YDir','normal') xlabel('time')

title('Hilbert-Huang spectrum')