I have a vector of data and it is normally distributed.
I get a clear bell shape from the chart.
Question is how do I get data only belonging to 1sd (68% of data)
Suppose you vector is
x, you can use
x[abs(x - mean(x)) < sd(x)] to extract data distributed around 1 standard error of the mean.
An alternative method (maybe more preferred) is
x[abs(scale(x)) < 1], where
scale(x) gives standardized / normalized