Closed Peter230655 closed 3 months ago
tjstienstra
commented
4 months ago Yeah, I actually guess that this is a bug. The plot constraint function should never crash after successfully solving a problem. I also remember having the same problem and writing my own version of this function.
tjstienstra
commented
4 months ago Just gave the source code a quick read. The problem is in the slicing of the selecting the values of the instance constraints of the free vector. It uses con_violations[self.collocator.num_states * N:] and forgets the unknown input trajectories.
Peter230655
commented
4 months ago Thanks!
tjstienstra
commented
4 months ago Just gave the source code a quick read. The problem is in the slicing of the selecting the values of the instance constraints of the free vector. It uses
con_violations[self.collocator.num_states * N:]and forgets the unknown input trajectories.
Oh wait, this statement is incorrect, we are dealing here with the constraints vector, not the free vector. I'll have to check how this array is actually formatted.
moorepants
commented
4 months ago There is this probably related issue #53 .
tjstienstra
commented
4 months ago There is this probably related issue #53 .
I think it is not exactly related (unless it really has to do with the initial slicing), but it can be easily fixed at the same time. I would propose something like the following, where I immediately also introduce the option to just plot all state violations in a single axis, as that is way more readable when having more states.
def plot_constraint_violations(self, vector, separate_state_axes=True):
con_violations = self.con(vector)
con_nodes = range(self.collocator.num_states, # Have to say that I do not exactly know where this part comes from
self.collocator.num_collocation_nodes + 1)
N = len(con_nodes)
n_state_axes = len(self.collocator.state_symbols) if separate_state_axes else 1
plot_instance_viols = self.coll_instance_constraints is not None
fig, axes = plt.subplots(n_state_axes + plot_instance_viols)
for i, symbol in enumerate(self.collocator.state_symbols):
state_violations = con_violations[i * N:i * N + N]
state_label = sm.latex(symbol, mode='inline')
if separate_state_axes:
axes[i].plot(con_nodes, state_violations)
axes[i].set_ylabel(state_label)
else:
axes[0].plot(con_nodes, state_violations, label=state_label)
if not separate_state_axes:
axes[0].legend()
axes[0].set_title('Constraint Violations')
axes[-plot_instance_viols - 1].set_xlabel('Node Number')
if plot_instance_viols:
left = range(len(self.collocator.instance_constraints))
axes[-1].bar(left, con_violations[-len(self.collocator.instance_constraints):],
tick_label=[sm.latex(s, mode='inline')
for s in self.collocator.instance_constraints])
axes[-1].set_ylabel('Instance')
axes[-1].set_xticklabels(axes[-1].get_xticklabels(), rotation=-10)
return axesPS a more future proof argument could be state_style="separate axes"
moorepants
commented
4 months ago Any improvement to the plots are welcome. I didn't spend too much time making them nice years ago when I drafted this.
Peter230655
commented
3 months ago Dumb question: Does this line: _prob.plot_constraint_violations(solution)__ plot the content of info[g], where info is the dictionary returned by solve? Thanks!
I am playing around with a opty simulation.
The last line (prob.plot_constraint_violations(solution)) gives this error:
However it does print some result:
What am I doing wrong? Thanks for any help!