function?[x_lambdarhoeta]?=?tikhonov（UsVblambdax_0）?
%TIKHONOV?Tikhonov?regularization.?
%?
%?[x_lambdarhoeta]?=?tikhonov（UsVblambdax_0）?
%?[x_lambdarhoeta]?=?tikhonov（UsmXblambdax_0）???sm?=?[sigmamu]?
%?
%?Computes?the?Tikhonov?regularized?solution?x_lambda.??If?the?SVD?
%?is?used?i.e.?if?U?s?and?V?are?specified?then?standard-form?
%?regularization?is?applied:?
%????min?{?||?A?x?-?b?||^2?+?lambda^2?||?x?-?x_0?||^2?}?.?
%?If?on?the?other?hand?the?GSVD?is?used?i.e.?if?U?sm?and?X?are?
%?specified?then?general-form?regularization?is?applied:?
%????min?{?||?A?x?-?b?||^2?+?lambda^2?||?L?（x?-?x_0）?||^2?}?.?
%?
%?If?x_0?is?not?specified?then?x_0?=?0?is?used.
%
%?Note?that?x_0?cannot?be?used?if?A?is?underdetermined?and?L?~=?I.
%?
%?If?lambda?is?a?vector?then?x_lambda?is?a?matrix?such?that?
%????x_lambda?=?[?x_lambda（1）?x_lambda（2）?...?]?.?
%?
%?The?solution?norm（standard-form?case）?or?seminorm?（general-form
%?case）?and?the?residual?norm?are?returned?in?eta?and?rho.?
?
%?Per?Christian?Hansen?IMM?April?14?2003.?
?
%?Reference:?A.?N.?Tikhonov?&?V.?Y.?Arsenin?“Solutions?of?
%?Ill-Posed?Problems“?Wiley?1977.?
?
%?Initialization.?
if?（min（lambda）<0）?
??error（‘Illegal?regularization?parameter?lambda‘）?
end?
m?=?size（U1）;
n?=?size（V1）;
[pps]?=?size（s）;?
beta?=?U（:1:p）‘*b;?
zeta?=?s（:1）.*beta;?
ll?=?length（lambda）;?x_lambda?=?zeros（nll）;?
rho?=?zeros（ll1）;?eta?=?zeros（ll1）;?
?
%?Treat?each?lambda?separately.?
if?（ps==1）?
??
??%?The?standard-form?case.
??if?（nargin==6）?omega?=?V‘*x_0;?end?
??for?i=1:ll?
????if?（nargin==5）?
??????x_lambda（:i）?=?V（:1:p）*（zeta./（s.^2?+?lambda（i）^2））;?
??????rho（