TI¶

The TI estimator is a simple implementation of thermodynamic integration that uses the trapezoid rule for integrating the space between $\left<\frac{dH}{d\lambda}\right>$ values for each $\lambda$ sampled.

API Reference¶

class alchemlyb.estimators.TI(verbose=False)¶

Thermodynamic integration (TI).

Parameters:: verbose (bool, optional) – Set to True if verbose debug output is desired.

delta_f_¶

The estimated dimensionless free energy difference between each state.

Type:: DataFrame

d_delta_f_¶

The estimated statistical uncertainty (one standard deviation) in dimensionless free energy differences.

Type:: DataFrame

states_¶

Lambda states for which free energy differences were obtained.

Type:: list

dhdl¶

The estimated dhdl of each state.

Type:: DataFrame

Changed in version 1.0.0: delta_f_, d_delta_f_, states_ are view of the original object.

fit(dHdl)¶

Compute free energy differences between each state by integrating dHdl across lambda values.

Parameters:: dHdl (DataFrame) – dHdl[n,k] is the potential energy gradient with respect to lambda for each configuration n and lambda k.

separate_dhdl()¶

For transitions with multiple lambda, the attr:dhdl would return a DataFrame which gives the dHdl for all the lambda states, regardless of whether it is perturbed or not. This function creates a list of pandas.Series for each lambda, where each pandas.Series describes the potential energy gradient for the lambdas state that is perturbed.

Returns:: dHdl_list – A list of pandas.Series such that dHdl_list[k] is the potential energy gradient with respect to lambda for each configuration that lambda k is perturbed.
Return type:: list

get_metadata_routing()¶

Get metadata routing of this object.

Please check User Guide on how the routing mechanism works.

Returns:: routing – A MetadataRequest encapsulating routing information.
Return type:: MetadataRequest

get_params(deep=True)¶

Get parameters for this estimator.

Parameters:: deep (bool, default=True) – If True, will return the parameters for this estimator and contained subobjects that are estimators.
Returns:: params – Parameter names mapped to their values.
Return type:: dict

set_fit_request(*, dHdl: bool | None | str = '$UNCHANGED$') → TI¶

Request metadata passed to the fit method.

Note that this method is only relevant if enable_metadata_routing=True (see sklearn.set_config()). Please see User Guide on how the routing mechanism works.

The options for each parameter are:

True: metadata is requested, and passed to fit if provided. The request is ignored if metadata is not provided.
False: metadata is not requested and the meta-estimator will not pass it to fit.
None: metadata is not requested, and the meta-estimator will raise an error if the user provides it.
str: metadata should be passed to the meta-estimator with this given alias instead of the original name.

The default (sklearn.utils.metadata_routing.UNCHANGED) retains the existing request. This allows you to change the request for some parameters and not others.

Added in version 1.3.

Note

This method is only relevant if this estimator is used as a sub-estimator of a meta-estimator, e.g. used inside a Pipeline. Otherwise it has no effect.

Parameters:: dHdl (str, True, False, or None, default=sklearn.utils.metadata_routing.UNCHANGED) – Metadata routing for dHdl parameter in fit.
Returns:: self – The updated object.
Return type:: object

set_params(**params)¶

Set the parameters of this estimator.

The method works on simple estimators as well as on nested objects (such as Pipeline). The latter have parameters of the form <component>__<parameter> so that it’s possible to update each component of a nested object.

Parameters:: **params (dict) – Estimator parameters.
Returns:: self – Estimator instance.
Return type:: estimator instance