pub trait ScalarOps {
// Required methods
fn scalar_subtract(&self, scalar: f64) -> Result<NDArray<f64>, String>;
fn scalar_mult(&self, scalar: f64) -> Result<NDArray<f64>, String>;
fn scalar_add(&self, scalar: f64) -> Result<NDArray<f64>, String>;
fn scalar_div(&self, scalar: f64) -> Result<NDArray<f64>, String>;
}