Sum of a series containing table column data
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I have a table, T, with one column of data of length 12054. I need to then make the following sum
SUM_[k=0 to t-1] 0.5^abs(k-5)*T(t-k)
lambda(t) = 1 + ---------------------------------------------------------------
SUM_[k=0 to t-1] 0.5^abs(k-5)
I have tried using symsum and defining the numerator and denominator seperately but I cannot seem to get it right. If anyone could help me with this it would be much appreciated.
Edit: Below is my attempt
syms k x;
% S1(t) is my attempt at defining the numerator
S1(t) = symsum(0.5^(abs(k-5)*T(t-k)),k,0,t-1);
Unrecognized function or variable 't'.
% Next is my attempt at defining the denominator
for t=0:12054
S2(t) = symsum(0.5^(abs(k-5)),k,0,t-1);
end
Array indices must be positive integers or logical values.
Error in sym/privsubsasgn (line 1151)
L_tilde2 =
builtin('subsasgn',L_tilde,struct('type','()','subs',{varargin}),R_tilde);
Error in sym/subsasgn (line 972)
C = privsubsasgn(L,R,inds{:});
Edit 2: Second attempt at defining the numerator
syms k x;
>> for t=1:12054
S1(t) = symsum(0.5^(abs(k-5)*T(t-k)),k,0,t-1);
end
Error using sym/subsindex (line 864)
Invalid indexing or function definition. Indexing must follow MATLAB indexing. Function arguments
must be symbolic variables, and function body must be sym expression.
2 个评论
Yongjian Feng
2021-7-4
It makes more sense if you post your solution here first, then we can help you to improve it.
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更多回答(1 个)
Sulaymon Eshkabilov
2021-7-4
What is the value of k? Just presuming k is taken from the number of elements in T, the calc can be done, e.g:
k=0:numel(T)-1;
L=1+sum(.5.^abs(k-5)*T(1:end-k))./sum(.5.^abs(k-5));
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