function [pf,a,si]=zhaochun1(a,h,wucha1)
chun_num=0;
while 1
chun_num=chun_num+1;
t=1:length(h);
[envmin,envmax,envmoy,indmin,indmax,indzer] = envelope(t,h,'spline');
mi=(envmax+envmin)./2;
ai=abs(envmax-envmin)./2;
a=a.*ai;
si=(h-mi)./ai;
h=si;
ai_funmax=max(ai);
ai_funmin=min(ai);
if (ai_funmax<=1+wucha1&&ai_funmin>=1-wucha1)
break
end
end
pf=a.*si;
chun_num
function [envmin, envmax,envmoy,indmin,indmax,indzer] = envelope(t,x,INTERP)
%computes envelopes and mean with various interpolations
NBSYM = 2; % 边界延拓点数
DEF_INTERP = 'spline';
if nargin < 2
x = t;
t = 1:length(x);
INTERP = DEF_INTERP;
end
if nargin == 2
if ischar(x)
INTERP = x;
x = t;
t = 1:length(x);
end
end
if ~ischar(INTERP)
error('interp parameter must be ''linear'''', ''cubic'' or ''spline''')
end
if ~any(strcmpi(INTERP,{'linear','cubic','spline'}))
error('interp parameter must be ''linear'''', ''cubic'' or ''spline''')
end
if min([size(x),size(t)]) > 1
error('x and t must be vectors')
end
s = size(x);
if s(1) > 1
x = x';
end
s = size(t);
if s(1) > 1
t = t';
end
if length(t) ~= length(x)
error('x and t must have the same length')
end
lx = length(x);
[indmin,indmax,indzer] = extr(x,t);
%boundary conditions for interpolation
[tmin,tmax,xmin,xmax] = boundary_conditions(indmin,indmax,t,x,NBSYM);
% definition of envelopes from interpolation
envmax = interp1(tmax,xmax,t,INTERP);
envmin = interp1(tmin,xmin,t,INTERP);
if nargout > 2
envmoy = (envmax + envmin)/2;
end
end
function [tmin,tmax,xmin,xmax] = boundary_conditions(indmin,indmax,t,x,nbsym)
% computes the boundary conditions for interpolation (mainly mirror symmetry)
lx = length(x);
% 判断极值点个数
if (length(indmin) + length(indmax) < 3)
error('not enough extrema')
end
% 插值的边界条件
if indmax(1) < indmin(1)% 第一个极值点是极大值
if x(1) > x(indmin(1))% 以第一个极大值为对称中心
lmax = fliplr(indmax(2:min(end,nbsym+1)));
lmin = fliplr(indmin(1:min(end,nbsym)));
lsym = indmax(1);
else% 如果第一个采样值小于第一个极小值,则将认为该值是一个极小值,以该点为对称中心
lmax = fliplr(indmax(1:min(end,nbsym)));
lmin = [fliplr(indmin(1:min(end,nbsym-1))),1];
lsym = 1;
end
else
if x(1) < x(indmax(1))% 以第一个极小值为对称中心
lmax = fliplr(indmax(1:min(end,nbsym)));
lmin = fliplr(indmin(2:min(end,nbsym+1)));
lsym = indmin(1);
else% 如果第一个采样值大于第一个极大值,则将认为该值是一个极大值,以该点为对称中心
lmax = [fliplr(indmax(1:min(end,nbsym-1))),1];
lmin = fliplr(indmin(1:min(end,nbsym)));
lsym = 1;
end
end
% 序列末尾情况与序列开头类似
if indmax(end) < indmin(end)
if x(end) < x(indmax(end))
rmax = fliplr(indmax(max(end-nbsym+1,1):end));
rmin = fliplr(indmin(max(end-nbsym,1):end-1));
rsym = indmin(end);
else
rmax = [lx,fliplr(indmax(max(end-nbsym+2,1):end))];
rmin = fliplr(indmin(max(end-nbsym+1,1):end));
rsym = lx;
end
else
if x(end) > x(indmin(end))
rmax = fliplr(indmax(max(end-nbsym,1):end-1));
rmin = fliplr(indmin(max(end-nbsym+1,1):end));
rsym = indmax(end);
else
rmax = fliplr(indmax(max(end-nbsym+1,1):end));
rmin = [lx,fliplr(indmin(max(end-nbsym+2,1):end))];
rsym = lx;
end
end
% 将序列根据对称中心,镜像到两边
tlmin = 2*t(lsym)-t(lmin);
tlmax = 2*t(lsym)-t(lmax);
trmin = 2*t(rsym)-t(rmin);
trmax = 2*t(rsym)-t(rmax);
% in case symmetrized parts do not extend enough% 如果对称的部分没有足够的极值点
if tlmin(1) > t(1) | tlmax(1) > t(1)% 对折后的序列没有超出原序列的范围
if lsym == indmax(1)
lmax = fliplr(indmax(1:min(end,nbsym)));
else
lmin = fliplr(indmin(1:min(end,nbsym)));
end
if lsym == 1% 这种情况不应该出现,程序直接中止
error('bug')
end
lsym = 1; % 直接关于第一采样点取镜像
tlmin = 2*t(lsym)-t(lmin);
tlmax = 2*t(lsym)-t(lmax);
end
% 序列末尾情况与序列开头类似
if trmin(end) < t(lx) | trmax(end) < t(lx)
if rsym == indmax(end)
rmax = fliplr(indmax(max(end-nbsym+1,1):end));
else
rmin = fliplr(indmin(max(end-nbsym+1,1):end));
end
if rsym == lx
error('bug')
end
rsym = lx;
trmin = 2*t(rsym)-t(rmin);
trmax = 2*t(rsym)-t(rmax);
end
% 延拓点上的取值
xlmax =x(lmax);
xlmin =x(lmin);
xrmax =x(rmax);
xrmin =x(rmin);
% 完成延拓
tmin = [tlmin t(indmin) trmin];
tmax = [tlmax t(indmax) trmax];
xmin = [xlmin x(indmin) xrmin];
xmax = [xlmax x(indmax) xrmax];
end
%---------------------------------------------------------------------------------------------------
% 极值点和过零点位置提取
function [indmin, indmax, indzer] = extr(x,t);
%extracts the indices corresponding to extrema
if(nargin==1)
t=1:length(x);
end
m = length(x);
if nargout > 2
x1=x(1:m-1);
x2=x(2:m);
indzer = find(x1.*x2<0);
if any(x == 0)
iz = find( x==0 );
indz = [];
if any(diff(iz)==1)
zer = x == 0;
dz = diff([0 zer 0]);
debz = find(dz == 1);
finz = find(dz == -1)-1;
indz = round((debz+finz)/2);
else
indz = iz;
end
indzer = sort([indzer indz]);
end
end
d = diff(x);
n = length(d);
d1 = d(1:n-1);
d2 = d(2:n);
indmin = find(d1.*d2<0 & d1<0)+1;
indmax = find(d1.*d2<0 & d1>0)+1;
% when two or more consecutive points have the same value we consider only one extremum in the middle of the constant area
% 当连续多个采样值相同时,把最中间的一个值作为极值点,处理方式与连0类似
if any(d==0)
imax = [];
imin = [];
bad = (d==0);
dd = diff([0 bad 0]);
debs = find(dd == 1);
fins = find(dd == -1);
if debs(1) == 1
if length(debs) > 1
debs = debs(2:end);
fins = fins(2:end);
else
debs = [];
fins = [];
end
end
if length(debs) > 0
if fins(end) == m
if length(debs) > 1
debs = debs(1:(end-1));
fins = fins(1:(end-1));
else
debs = [];
fins = [];
end
end
end
lc = length(debs);
if lc > 0
for k = 1:lc
if d(debs(k)-1) > 0
if d(fins(k)) < 0
imax = [imax round((fins(k)+debs(k))/2)];
end
else
if d(fins(k)) > 0
imin = [imin round((fins(k)+debs(k))/2)];
end
end
end
end
if length(imax) > 0
indmax = sort([indmax imax]);
end
if length(imin) > 0
indmin = sort([indmin imin]);
end
end
end
end