How to code this equation?

To improve the significance of the data, a comprehensive evaluation parameter was set in the experiment so that the average values of different sets of test data could be presented in a consistent manner:

where n is the sample size, Yi is the result of testing on a certain sample, and Y_ is the average value.

How to code this equation?

Answer 1

[galaxy]

This formula mean Y = sum of all Y(i) value with i = 1:n

I do not know what is Y(i) so can not write detai.

Please refer symsum

[Alvin Alvin]

Average gradient (AG). The AG reflects the ability to express the details of an image and can be used to measure the

relative clarity of the image. AG is formulated as:

This is the code AG

[dfdx,dfdy] = gradient(f) ; 
M = (dfdx.^2+dfdy.^2)/2 ; 
AG = mean(mean(M)) ;

But need help with this equation

To improve the significance of the data, a comprehensive evaluation parameter was set in the experiment so that the average values of different sets of test data could be presented in a consistent manner:

where n is the sample size, Yi is the result of testing on a certain sample, and Y is the average value.

How to code this equation?

[Walter Roberson]

never represents . Instead it represents which is easily expressed as mean(Y)

[galaxy]

If Y is the average value, so the formular will as same as following.

You can use the code from Walter Roberson.

[Walter Roberson]

M = (dfdx.^2+dfdy.^2)/2 ; 

should be

g = sqrt((dfdx.^2+dfdy.^2)/2);
AG = mean(g(:));

As well as the missing sqrt(), you should not be assigning to M as you are using M for an array size.

[Alvin Alvin]

thanks Walter Roberson, give your answer will accept your answer for this question

Answer 2

[Walter Roberson]

y_bar = mean(Y);

or

y_bar = sum(Y)./length(Y);

Note: the second of those will malfunction if Y is a 2D array that has more columns than it has rows. The equation does not describe what should happen for 2D arrays, so what the "correct" output is for that case can be argued.