Function linreg::lin_reg

pub fn lin_reg<I, F>(xys: I, x_mean: F, y_mean: F) -> Result<(F, F), Error> where
    I: Iterator<Item = (F, F)>,
    F: FloatCore, 

Calculates a linear regression with a known mean.

Lower-level linear regression function. Assumes that x_mean and y_mean have already been calculated. Returns Error::DivByZero if

• the slope is too steep to represent, approaching infinity.

Since there is a mean, this function assumes that xs and ys are both non-empty.

Returns Ok((slope, intercept)) of the regression line.