survival analysis - fminsearch censored MATLAB -

edit found y(c) in script gives error:

subscript indices must either real positive integers or logicals. 

but in example script y(c) prints values of y censored.

i trying use script found analysis of censored data. script works fine when try use own data error.

this example code:

% have (x,y) data n = 100; x = 10*rand(n,1); y = 5 + .5*x + randn(n,1); plot(x,y,'o','color',[.8 .8 .8]);  % it's censored, can't observe values larger 8 c = y>8 o = min(y,8); line(x,o,'marker','o','color','b','linestyle','none')  % if fit line data observe, no b = polyfit(x,o,1) s = norm(o-polyval(b,x))/sqrt(n) xx = linspace(0,10); line(xx,polyval(b,xx),'color','r')  % instead need likelihood function taket censoring account nloglik = @(p) - sum(log(normpdf(o(~c),p(1)*x(~c)+p(2),p(3)))) ...                - sum(log(1-normcdf(o(c),p(1)*x(c)+p(2),p(3))));  nloglik = @(p) - sum(log(normpdf(tof(~c),p(1)*z(~c)+p(2),p(3)))) ...            - sum(log(1-normcdf(tof(c),p(1)*z(c)+p(2),p(3)))); p = fminsearch(nloglik,[b,s]) 

here code:

load('uv.mat') % 18 column array  = 1 : length(uv{1,7})     if uv{1,7}(i) ~= 0         x(i)=log10(uv{1,4}(i));         y(i) = uv{1,7}(i);     end end c=zeros(length(y),1); % c stands censored i=1:length(y)     if uv{1,8}{i} == 'u' % u stands upper limit         c(i)=1;     end end  b = polyfit(x,y,1) s = norm(y-polyval(b,x))/sqrt(length(x)) nloglik = @(p) - sum(log(normpdf(y(~c),p(1)*x(~c)+p(2),p(3)))) ...                - sum(log(1-normcdf(y(c),p(1)*x(c)+p(2),p(3)))); p = fminsearch(nloglik,[b,s]) 

the error is:

subscript indices must either real positive integers or logicals.  error in @(p)-sum(log(normpdf(y(~c),p(1)*x(~c)+p(2),p(3))))-sum(log(1-normcdf(y(c),p(1)*x(c)+p(2),p(3))))   error in fminsearch (line 191) fv(:,1) = funfcn(x,varargin{:});  error in zwithcensoring (line 22)  %zwithcensoring name of script p = fminsearch(nloglik,[b,s]) 

i tried debug p seems called before defined. found nloglik function input parameter p.

how script give error not example script? , how past error?

change variable c logical, i.e.:

c = logical(c) 

before use indexing.

alternatively, create 'c' logical begin with:

c= false(length(y),1); % c stands censored i=1:length(y)     if uv{1,8}{i} == 'u' % u stands upper limit         c(i)=true;     end end 

if not work, posting working code fix problem.