at.plot.response

Plot Observable value as a function of Variable.

Functions

plot_response(var, obs, rng[, ax, xlabel, ...])

Plot obs values as a function of var.

plot_response(var, obs, rng, ax=None, xlabel='', ylabel='', title='', color_offset=0, **kwargs)

Plot obs values as a function of var.

Parameters:

• var (VariableBase) – Variable object.

• obs (ObservableList) – list of Observables.

• rng (Iterable[float]) – range of variation for the variable.

• ax (Axes | None) – Axes object. If None, a new figure will be created.

• xlabel (str) – x-axis label. If empty, the variable name will be used.

• ylabel (str) – y-axis label.

• title (str) – plot title.

• color_offset (int) – offset in the matplotlib line color cycle.

• **kwargs – Additional keyword arguments are transmitted to the Axes creation function.

Returns:

ax – the Axes object.

Example

Minimal example using only default values:

>>> obs = at.ObservableList(
...     [
...         at.EmittanceObservable("emittances", plane="x"),
...         at.EmittanceObservable("emittances", plane="y"),
...     ],
...     ring=ring,
... )
>>> var = at.AttributeVariable(ring, "energy", name="energy [eV]")
>>> plot_response(var, obs, np.arange(3.0e9, 6.01e9, 0.5e9))
>>>

Example showing the formatting possibilities by:

• using the Observable.plot_fmt attribute for line formatting,

• using the Observable.name attribute for curve labels,

• using dual y-axis by calling plot_response() twice,

• avoiding duplicate line colors with the color_offset parameter,

• using the ylabel and title parameters.

>>> obsleft =at.ObservableList(
...     [
...         at.LocalOpticsObservable(
...             [0], "beta", plane="x",
...             name=r"$\beta_x$",
...             plot_fmt={"linewidth": 3.0, "marker": "o"}
...         ),
...         at.LocalOpticsObservable(
...             [0], "beta", plane="y", name=r"$\beta_z$", plot_fmt="--"
...         )
...     ],
...     ring=ring
... )
>>>
>>> obsright =at.ObservableList(
...     [
...         at.GlobalOpticsObservable("tune", plane="x", name=r"$\nu_x$"),
...         at.GlobalOpticsObservable("tune", plane="y", name=r"$\nu_x$"),
...     ],
...     ring=ring
... )
>>> # On the left y-axis
>>> ax = at.plot_response(
...     var,
...     obsleft,
...     np.arange(2.4, 2.7, 0.02),
...     ylabel="beta [m]",
...     title="Example of plot_response"
... )
>>> # On the right y-axis
>>> ax2 = at.plot_response(
...     var,
...     obsright,
...     np.arange(2.4, 2.7, 0.02),
...     ylabel="tune",
...     ax=ax.twinx(),
...     color_offset=2
... )
>>> ax.set_ylim(0.0, 10.0)
>>> ax2.set_ylim(0.0, 1.2)
>>> ax2.grid(False)

Example varying an evaluation parameter:

>>> obs =at.ObservableList(
...     [
...         at.LocalOpticsObservable([0], "beta", plane="x", name=r"$\beta_x$"),
...         at.LocalOpticsObservable([0], "beta", plane="y", name=r"$\beta_z$")
...     ],
...     ring=ring,
...     dp = 0.0
... )
>>> var = at.EvaluationVariable(obs, "dp", name=r"$\delta$")
>>> ax=at.plot_response(
... var, obs, np.arange(-0.03, 0.0301,0.001), ylabel=r"$\beta\;[m]$"
... )