correlation and proportional weights

[Saloni Khurana]

Hello,
I am not able to use proportional weights with correlation but can use analytical weights.
Can anyone help me to explain the reason?

I am able to understand some intuition like correlation is not affected by the multiplier effect. But I am not sure, then why analytical weights are allowed!

commands:
corr x y [pw=freq]
error message:
pweights not allowed
r(101);