statsmodels.genmod.generalized_linear_model.GLMResults.get_prediction¶
- GLMResults.get_prediction(exog=None, exposure=None, offset=None, transform=True, which=None, linear=None, average=False, agg_weights=None, row_labels=None)[source]¶
Compute prediction results for GLM compatible models.
Options and return class depend on whether “which” is None or not.
- Parameters:
- exogarray_like,
optional
The values for which you want to predict.
- exposurearray_like,
optional
Exposure time values, only can be used with the log link function.
- offsetarray_like,
optional
Offset values.
- transformbool,
optional
If the model was fit via a formula, do you want to pass exog through the formula. Default is True. E.g., if you fit a model y ~ log(x1) + log(x2), and transform is True, then you can pass a data structure that contains x1 and x2 in their original form. Otherwise, you’d need to log the data first.
- which‘mean’, ‘linear’, ‘var’(
optional
) Statitistic to predict. Default is ‘mean’. If which is None, then the deprecated keyword “linear” applies. If which is not None, then a generic Prediction results class will be returned. Some options are only available if which is not None. See notes.
‘mean’ returns the conditional expectation of endog E(y | x), i.e. inverse of the model’s link function of linear predictor.
‘linear’ returns the linear predictor of the mean function.
‘var_unscaled’ variance of endog implied by the likelihood model. This does not include scale or var_weights.
- linearbool
The
linear` keyword is deprecated and will be removed, use ``which
keyword instead. If which is None, then the linear keyword is used, otherwise it will be ignored. If True and which is None, the linear predicted values are returned. If False or None, then the statistic specified bywhich
will be returned.- averagebool
Keyword is only used if
which
is not None. If average is True, then the mean prediction is computed, that is, predictions are computed for individual exog and then the average over observation is used. If average is False, then the results are the predictions for all observations, i.e. same length asexog
.- agg_weights
ndarray
,optional
Keyword is only used if
which
is not None. Aggregation weights, only used if average is True.- row_labels
list
of
str
orNone
If row_lables are provided, then they will replace the generated labels.
- exogarray_like,
- Returns:
- prediction_results
instance
of
a
PredictionResults
class. The prediction results instance contains prediction and prediction variance and can on demand calculate confidence intervals and summary tables for the prediction of the mean and of new observations. The Results class of the return depends on the value of
which
.
- prediction_results
See also
Notes
Changes in statsmodels 0.14: The
which
keyword has been added. Ifwhich
is None, then the behavior is the same as in previous versions, and returns the mean and linear prediction results. If thewhich
keyword is not None, then a generic prediction results class is returned and is not backwards compatible with the old prediction results class, e.g. column names of summary_frame differs. There are more choices for the returned predicted statistic usingwhich
. More choices will be added in the next release. Two additional keyword, average and agg_weights options are now also available ifwhich
is not None. In a future versionwhich
will become not None and the backwards compatible prediction results class will be removed.