    fun = inline('x * atan(x) - 0.5 * log(1 + x * x)');
funprim = inline('atan(x)');
 funbis = inline('1 / (1 + x * x)');
[x, f, ok, count] = newton1D(fun, funprim, funbis, 1.5, 1.e-6, 20)
 