I often see the same method for computing voltage distribution in electronic circuits implying components whose V-I curves are not trivial.
For example, in a circuit implying a resistor and a LED having 2V / 20mA caracteristics, we substract 2V from the supply voltage to determine the remaining resistor's voltage, and we assume current in the whole circuit is 20mA to determine resistor's value using Ohm's law. But what about a direct computation? If the resistor's value is too low, the LED voltage would be higher than this ; on the other way, if the resistor's value is too high, the LED voltage will be lower.
Is there a standard way to compute voltage distribution directly, based on chosen components (i.e. the inverse of the method that determines other components)? And more generally, is the voltage distribution always unique?