averages of a matrix

Given variable A that contains a row vector of values, and variable w that contains a row vector of weights, compute the weighted average of A and store the result into variable W_A

Examples: Inputs A = [1 2 3], w = [4 6 1] Output W_A = (1*4 + 2*6 + 3*1)/3 = 6.3333

 Inputs  A = [5.4 3 2.1 7], w = [1 1 0.5 1]
 Output W_A = (5.4*1 + 3*1 + 2.1*0.5 + 7*1)/4 = 4.1125

I don't think the question is asking about weighted avg properly, so you can ignore that. I am just trying to figure out the proper code that would be capable of solving the example problems above...

[Salaheddin Hosseinzadeh]

Anthony

Be careful what you want. Star Strider mentioned a good point.

Answer 1

[Star Strider]

The weighted mean is the sum of the product of the values times the weights divided by the sum of the weights:

WgtdMean = sum(A.*w)/sum(w);

See the Wikipedia article: Weighted arithmetic mean.

Answer 2

[Salaheddin Hosseinzadeh]

Hi Anthony,

This is very basic, please read more

output = mean(A.*B)

That's all