Talk:GLPK/Electricity markets

Modeling lower and upper bounds
var ramp {I}; s.t. positive_feasible_ramp_rate {i in I}: ramp[i] <= max_ramp_rate; s.t. negative_feasible_ramp_rate {i in I}: -ramp[i] <= max_ramp_rate; could be replaced by var ramp {I}, >= - max_ramp_rate, <= max_ramp_rate;

The difference is negligable for small models but may be interesting for larger ones.

Pro Contra
 * speed up due to lower number of equations
 * reduced memory consumption
 * no dual value available for analysis

-- Xypron (talk) 05:34, 6 July 2010 (UTC)