When I run the code with any values for a to e and select integration or differentiation my code panics saying that there is a dimension mismatch and I’m not sure why. For reference here is the code I am using

use std::io::{self, Write};
use std::thread;
use std::time::Duration;
use nalgebra::{DMatrix, DVector};

fn main() {

    // Initialize polynomial coefficients
    let (a, b, c, d, e) = (0.0, 0.0, 0.0, 0.0, 0.0);

    let mut _polynomial_vec = DVector::from_row_slice(&[a, b, c, d, e]);

    // Derivative matrix
    let derivative_mat = DMatrix::from_row_slice(5, 5, &[
        0.0, 1.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 2.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 3.0, 0.0,
        0.0, 0.0, 0.0, 0.0, 4.0,
        0.0, 0.0, 0.0, 0.0, 0.0,
    ]);

    // Integration matrix
    let integration_mat = DMatrix::from_row_slice(5, 6, &[
        0.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        1.0, 0.0, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.5, 0.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 1.0 / 3.0, 0.0, 0.0, 0.0,
        0.0, 0.0, 0.0, 0.25, 0.0, 0.0,
    ]);

    loop {
        println!("Please enter 5 values for the vector:");
        io::stdout().flush().unwrap();

        let mut input = String::new();
        io::stdin().read_line(&mut input).unwrap();

        let values: Vec<f64> = input.trim()
                                    .split_whitespace()
                                    .map(|s| s.parse().unwrap())
                                    .collect();

        if values.len() == 5 {
            let (a, b, c, d, e) = (values[0], values[1], values[2], values[3], values[4]);
            println!("Your Polynomial is {}x^4 + {}x^3 + {}x^2 + {}x + {}", a, b, c, d, e);
            
            _polynomial_vec = DVector::from_row_slice(&[a, b, c, d, e]);
            break;
        } else {
            println!("Please enter exactly 5 values for the vector.");
        }
    }
loop{
    println!("For Integration please enter I, for Differentiation please enter D");
    let mut input = String::new();
    io::stdin().read_line(&mut input).unwrap();
    let input = input.trim();

    match input {
        "D" | "d" => {
            let derivative_vec = _polynomial_vec * derivative_mat;
            println!("The derivative of your polynomial is: {}x^3 + {}x^2 + {}x + {}", derivative_vec[3], derivative_vec[2], derivative_vec[1], derivative_vec[0]);
            break;
        }
        "I" | "i" => {
            let extended_vec = _polynomial_vec.insert_row(0, 0.0);

            let integral_vec = extended_vec * integration_mat;
            println!("The integral of your polynomial is: {}x^5 + {}x^4 + {}x^3 + {}x^2 + {}x + C", 
                integral_vec[5], integral_vec[4], integral_vec[3], integral_vec[2], integral_vec[1]);
                break;
        },
        _ => continue,
    };
};
    println!("Closing in 5 seconds...");
    thread::sleep(Duration::from_secs(5));
}

I’ve tried to swap the rows and columns of my matrix but I still receive the same error. I’ve also tried swapping the order of the multiplication but then the multiplication gives wrong polynomials for any term except for 1.