I'd like to plot the Hermite polynomials in the same graph without having to type them one by one using a loop. I've tried something like this:

```
    H0(x) = 1 
    H1(x) = 2*x 
    H2(x) = 4*x*x-2 
    H3(x) = 8*x**3-12*x 
    H4(x) = 16*x**4-48*x**2+12 
    H5(x) = 32*x**5-160*x**3+120*x

    plot for[i=0:5] H.i(x)

```

but It won't work, it'll say: `undefined variable: H`. I've seen the variable `i` can be used as a string but I haven't been able to find if there's a way to use it as a string when calling a function.