Observation with trend line in the normal distribution plot ?

I am trying to plot my data in the form of normal probability with a fitted line. however, the area under the curve exceeds 1. any thought on this?

function mynormplot(Y)

S=sort(Y);

pi=(1:length(S))/(1+length(S));

zi=norminv(pi); % Since standard normal CDF hence, mean and STD is 0 & 1 respectively

plot(S,zi,'o');

hold

T=(S-mean(Y))/std(Y);

plot(S,T,'k');

end

Answer 1

[Star Strider]

I have no idea what ‘pi’ is supposed to be (and please don’t use built-in function names for variable names, since pi=3.14...).

The norminv function requires that you define the mean and standard deviation in its argument list. You are giving it ‘pi’ as an argument, so it is yours to guess what it is assuming are the mean and standard deviation.

[Hydro]

Thanks star, i figured my mistake..you are right, i shouldnt name the variable as the buildt in function.

thanks,

[Star Strider]

My pleasure!