/*
    Recursive generating formula for Laguerre polynomial and it's
    derivative.

    Shows that f(n,x).rms == (df(n,x).val*x.rms) (which is
    f'(n,x)*deltaX) 
*/

f(n,x)
{
  if (n<=0) return 1; 
  if (n==1) return -x+1; 
  return ((2*n-1-x)*f(n-1,x)-(n-1)*f(n-2,x))/n;
}

df(n,x)
{
  return (n*f(n,x)-n*f(n-1,x))/x;
}

test(x)
{
   auto n,i,y;
   for(i=1;i<10;i++) {print "l(",i%-6.2f,",",x%-6.2f,")= ",f(i,x)," ",fabs(df(i,x).val*x.rms),"\n";};
}

