'Place x0 = f() in the vector of all variables.'

def place_x0(self, big_x, var_offsets):

    (m, x0) = self.f()
    offset = 0
    for var in self.variables():
        var_size = (var.size[0] * var.size[1])
        var_x0 = x0[offset:(offset + var_size)]
        self.block_add(big_x, var_x0, var_offsets[var.data], 0, var_size, 1)
        offset += var_size
