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function result = logsum(logv)
len = length(logv);
if (len<2);
error('Subroutine logsum cannot sum less than 2 terms.');
end;
% First two terms
if (logv(2)<logv(1)),
result = logv(1) + log( 1 + exp( logv(2)-logv(1) ) );
else,
result = logv(2) + log( 1 + exp( logv(1)-logv(2) ) );
end;
% Remaining terms
for (i=3:len),
term = logv(i);
if (result<term),
result = term + log( 1 + exp( result-term ) );
else,
result = result + log( 1 + exp( term-result ) );
end;
end
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