Function rect_profile_values 

pub fn rect_profile_values(
    width: u32,
    height: u32,
    data: &[f32],
    rect: (f64, f64, f64, f64),
    horizontal: bool,
    method: ProfileMethod,
) -> Result<(Vec<f64>, Vec<f64>), PlotDataError>

Extract a 1D profile within a rectangle by reducing along an axis.

rect is (x_min, x_max, y_min, y_max) in (column, row) coordinates. method selects the band reduction (silx profile method): ProfileMethod::Mean averages the band, ProfileMethod::Sum integrates it (silx numpy.mean / numpy.sum over the rectangle’s short axis).