1. A method for determining active constraint equations in a network, comprising: selecting at least one constraint equation for a connection in the network, each constraint equation including a respective slack variable and a respective slack variable multiplier; selecting a base equation for each connection in the network, the base equation for the network connection with the at least one constraint equation including the respective slack variable of each constraint equation and another respective slack variable multiplier for the respective slack variable of each constraint equation; solving for each respective slack variable using a computer system; adjusting a respective parameter for each respective slack variable multiplier and each respective another slack variable multiplier between two predetermined values based on a solution for each respective slack variable; repeating the steps of solving for each respective slack variable and adjusting a respective parameter for each respective slack variable multiplier and each respective another slack variable multiplier until each respective parameter is equal to one of the two predetermined values; and determining whether each constraint equation in the network is active based on the one of the two predetermined values for each respective parameter.