Method i2x

tools/streamline.rs:209–211

(&self, i: usize)

    }

    fn i2x(&self, i: usize) -> f64 {
        (i as f64) * self.stride + self.min_x
    }

    fn j2y(&self, j: usize) -> f64 {
        (j as f64) * self.stride + self.min_y