summation divided by summation

Hey, the beautiful pupil of the world. I'm trying to implant the formula below to MATLAB. I wrote the denominator and the numerator in different 'for' loops but it doesn't work like that. then, I tried to use special sum code but it didn't work either. so, could you help me to solve this problem?
here is the code I used;
a=2;
l=2;
d1= (sum(l,l,0,l))*(r1.^a)./(sum(r1.^a,l,0,l));
d2= (sum(l,l,0,l))*(r2.^a)./(sum(r2.^a,l,0,l));
thanks in advance.

9 Comments

Show us your code......we will edit it to the present one.
here you are, sir.
>> sum(l,l,0,l)
Error using sum
Trailing string input must be 'double', 'native', 'default', 'omitnan' or 'includenan'.
Read about the function sum in the documentation.
What is your sum ? It does not appear to be the MATLAB sum function. It is confusing for the people reading the code when you use a name so similar to the standard MATLAB name.
Is r1 a vector or an array?
What is the part that looks like (l) ? Is it floor(l) or just brackets? Is that exp(l) or l^l at the beginning?
Dear Walter, r1 and r2 are arrays. the thing is d1 and d2 are the last constants i need to calculate. others I've already found. so you can assume that r1 and r2 are constant values.
about the l, it is writing in the formula.
How about l?
it is supposed to be division. but it must be ./ thanks for showing me.
@Onur: Did you consider the advice concerning "sum"? sum() is a built-in function, but calling it like sum(l,l,0,l) is not valid. If your "sum" is a user-defined function, use a different name, because shadowing important built-in functions is not an error, but very confusing.
Everyone, I'm really appreciated that you helped me. I finally find my mistakes and solve them. Now I have another problem. If you want to help me, please check this page; https://www.mathworks.com/matlabcentral/answers/369732-implementation-of-the-cross-correlation

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Answers (1)

Walter Roberson
Walter Roberson on 28 Nov 2017
Change your / to ./
And you should probably have about 30 or 40 lines of comments explaining in detail why you feel it is necessary to name your variable or custom function sum in conflict with the standard MATLAB function sum()

1 Comment

Onur Demir
Onur Demir on 28 Nov 2017
Edited: per isakson on 29 Nov 2017
Walter, I'm really appreciated that you helped me. I finally find my mistakes and solve them. Now I have another problem. If you want to help me, please check this page; https://www.mathworks.com/matlabcentral/answers/369732-implementation-of-the-cross-correlation

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on 28 Nov 2017

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on 29 Nov 2017

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