State Space Model bug in 9.0.1
- To: mathgroup at smc.vnet.net
- Subject: [mg130383] State Space Model bug in 9.0.1
- From: gndpics at gmail.com
- Date: Sat, 6 Apr 2013 05:13:13 -0400 (EDT)
- Delivered-to: l-mathgroup@mail-archive0.wolfram.com
- Delivered-to: l-mathgroup@wolfram.com
- Delivered-to: mathgroup-newout@smc.vnet.net
- Delivered-to: mathgroup-newsend@smc.vnet.net
When creating the state space model of a PID filter: pid = StateSpaceModel[TransferFunctionModel[kp + ki/s + kd*s, s]] I obtain different results depending on the version of Mathematica: - in 9.0: StateSpaceModel[{{{0, 0, 0}, {0, 1, 0}, {0, 0, 1}}, {{1}, {0}, {1}}, {{ki, -kd, -kp}}, {{0}}, {{1, 0, 0}, {0, 0, 1}, {0, 0, 0}}}, SamplingPeriod -> None, SystemsModelLabels -> None] - in 9.0.1: StateSpaceModel[{{{0, 0, 0}, {0, 1, 0}, {0, 0, 1}}, {{1}, {0}, {1}}, {{ki, kd, kp}}, {{0}}, {{1, 0, 0}, {0, 0, 1}, {0, 0, 0}}}, SamplingPeriod -> None, SystemsModelLabels -> None] Unfortunately I think the 9.0.1 answer is wrong. Can anyone help me on this? Thank you, Gianni