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LinearAnalysis object, which is the base class for other pyemu analysis objects (Schur, ErrVar, MonteCarlo, and EnsembleSmoother). This class is usually not used directly.

LinearAnalysis

Bases: object

The base/parent class for linear analysis.

Parameters:

Name Type Description Default
jco varies

something that can be cast or loaded into a pyemu.Jco. Can be a str for a filename or pyemu.Matrix/pyemu.Jco object.

None
pst varies

something that can be cast into a pyemu.Pst. Can be an str for a filename or an existing pyemu.Pst. If None, a pst filename is sought with the same base name as the jco argument (if passed)

None
parcov varies

prior parameter covariance matrix. If str, a filename is assumed and the prior parameter covariance matrix is loaded from a file using the file extension (".jcb"/".jco" for binary, ".cov"/".mat" for PEST-style ASCII matrix, or ".unc" for uncertainty files). If None, the prior parameter covariance matrix is constructed from the parameter bounds in LinearAnalysis.pst. Can also be a pyemu.Cov instance

None
obscov varies

observation noise covariance matrix. If str, a filename is assumed and the noise covariance matrix is loaded from a file using the file extension (".jcb"/".jco" for binary, ".cov"/".mat" for PEST-style ASCII matrix, or ".unc" for uncertainty files). If None, the noise covariance matrix is constructed from the observation weights in LinearAnalysis.pst. Can also be a pyemu.Cov instance

None
forecasts varies

forecast sensitivity vectors. If str, first an observation name is assumed (a row in LinearAnalysis.jco). If that is not found, a filename is assumed and predictions are loaded from a file using the file extension. If [str], a list of observation names is assumed. Can also be a pyemu.Matrix instance, a numpy.ndarray or a collection of pyemu.Matrix or numpy.ndarray.

None
ref_var float

reference variance. Default is 1.0

1.0
verbose `bool`

controls screen output. If str, a filename is assumed and and log file is written.

False
sigma_range `float`

defines range of upper bound - lower bound in terms of standard deviation (sigma). For example, if sigma_range = 4, the bounds represent 4 * sigma. Default is 4.0, representing approximately 95% confidence of implied normal distribution. This arg is only used if constructing parcov from parameter bounds.

4.0
scale_offset `bool`

flag to apply parameter scale and offset to parameter bounds when calculating prior parameter covariance matrix from bounds. This arg is onlyused if constructing parcov from parameter bounds.Default is True.

True

Note:

Can be used directly, but for prior uncertainty analyses only.

The derived types (`pyemu.Schur`, `pyemu.ErrVar`) are for different
forms of FOMS-based posterior uncertainty analyses.

This class tries hard to not load items until they are needed; all arguments are optional.

The class makes heavy use of property decorator to encapsulated private attributes

Example::

#assumes "my.pst" exists
la = pyemu.LinearAnalysis(jco="my.jco",forecasts=["fore1","fore2"])
print(la.prior_forecast)

adj_par_names property

adjustable parameter names

Returns:

Type Description

['str`]: list of adjustable parameter names

Note

if LinearAnalysis.pst is None, returns LinearAnalysis.jco.col_names

fehalf property

Karhunen-Loeve scaling matrix attribute.

Returns:

Type Description

pyemu.Matrix: the Karhunen-Loeve scaling matrix based on the prior

parameter covariance matrix

forecast_names property

get the forecast (aka prediction) names

Returns:

Type Description
[`str`]

list of forecast names

forecasts property

the forecast sentivity vectors attribute

Returns:

Type Description

pyemu.Matrix: a matrix of forecast (prediction) sensitivity vectors (column wise)

forecasts_iter property

forecast (e.g. prediction) sensitivity vectors iterator

Returns:

Type Description

iterator: iterator on forecasts (e.g. predictions) sensitivity vectors (matrix)

Note

This is used for processing huge numbers of predictions

This is a synonym for LinearAnalysis.predictions_iter()

jco property

the jacobian matrix attribute

Returns:

Type Description

pyemu.Jco: the jacobian matrix attribute

mle_covariance property

maximum likelihood parameter covariance matrix.

Returns:

Type Description

pyemu.Matrix: maximum likelihood parameter covariance matrix

mle_parameter_estimate property

maximum likelihood parameter estimate.

Returns:

Type Description

pandas.Series: the maximum likelihood parameter estimates

nnz_obs_names property

non-zero-weighted observation names

Returns:

Type Description

['str`]: list of non-zero-weighted observation names

Note

if LinearAnalysis.pst is None, returns LinearAnalysis.jco.row_names

obscov property

get the observation noise covariance matrix attribute

Returns:

Type Description

pyemu.Cov: a reference to the LinearAnalysis.obscov attribute

parcov property

get the prior parameter covariance matrix attribute

Returns:

Type Description

pyemu.Cov: a reference to the LinearAnalysis.parcov attribute

predictions property

the prediction (aka forecast) sentivity vectors attribute

Returns:

Type Description

pyemu.Matrix: a matrix of prediction sensitivity vectors (column wise)

predictions_iter property

prediction sensitivity vectors iterator

Returns:

Type Description

iterator: iterator on prediction sensitivity vectors (matrix)

Note

this is used for processing huge numbers of predictions

prior_forecast property

prior forecast (e.g. prediction) variances

Returns:

Type Description

dict: a dictionary of forecast name, prior variance pairs

prior_parameter property

prior parameter covariance matrix

Returns:

Type Description

pyemu.Cov: prior parameter covariance matrix

prior_prediction property

prior prediction (e.g. forecast) variances

Returns:

Type Description

dict: a dictionary of prediction name, prior variance pairs

pst property

the pst attribute

Returns:

Type Description

pyemu.Pst: the pst attribute

qhalf property

square root of the cofactor matrix attribute. Create the attribute if it has not yet been created

Returns:

Type Description

pyemu.Matrix: square root of the cofactor matrix

qhalfx property

half normal matrix attribute.

Returns:

Type Description

pyemu.Matrix: half normal matrix attribute

xtqx property

normal matrix attribute.

Returns:

Type Description

pyemu.Matrix: normal matrix attribute

__fromfile(filename, astype=None)

a private method to deduce and load a filename into a matrix object. Uses extension: 'jco' or 'jcb': binary, 'mat','vec' or 'cov': ASCII, 'unc': pest uncertainty file.

__load_jco()

private method to set the jco attribute from a file or a matrix object

__load_obscov()

private method to set the obscov attribute from: a pest control file (observation weights) a pst object a matrix object an uncert file an ascii matrix file

__load_parcov()

private method to set the parcov attribute from: a pest control file (parameter bounds) a pst object a matrix object an uncert file an ascii matrix file

__load_predictions()

private method set the predictions attribute from

mixed list of row names, matrix files and ndarrays a single row name an ascii file

can be none if only interested in parameters.

__load_pst()

private method set the pst attribute

adjust_obscov_resfile(resfile=None)

reset the elements of obscov by scaling the implied weights based on the phi components in res_file so that the total phi is equal to the number of non-zero weights.

Parameters:

Name Type Description Default
resfile `str`

residual file to use. If None, residual file with case name is sought. default is None

None
Note

calls pyemu.Pst.adjust_weights_resfile()

apply_karhunen_loeve_scaling()

apply karhuene-loeve scaling to the jacobian matrix.

Note:

This scaling is not necessary for analyses using Schur's
complement, but can be very important for error variance
analyses.  This operation effectively transfers prior knowledge
specified in the parcov to the jacobian and reset parcov to the
identity matrix.

clean()

drop regularization and prior information observation from the jco

drop_prior_information()

drop the prior information from the jco and pst attributes

get(par_names=None, obs_names=None, astype=None)

method to get a new LinearAnalysis class using a subset of parameters and/or observations

Parameters:

Name Type Description Default
par_names [`'str`]

par names for new object

None
obs_names [`'str`]

obs names for new object

None
astype `pyemu.Schur` or `pyemu.ErrVar`

type to cast the new object. If None, return type is same as self

None

Returns:

Type Description

LinearAnalysis: new instance

get_cso_dataframe()

get a dataframe of composite observation sensitivity, as returned by PEST in the seo file.

Returns:

Type Description

pandas.DataFrame: dataframe of observation names and composite observation

sensitivity

Note

That this formulation deviates slightly from the PEST documentation in that the values are divided by (npar-1) rather than by (npar).

The equation is cso_j = ((Q^1/2JJ^T*Q^1/2)^1/2)_jj/(NPAR-1)

get_obs_competition_dataframe()

get the observation competition stat a la PEST utility

Returns:

Type Description

pandas.DataFrame: a dataframe of observation names by

observation names with values equal to the PEST

competition statistic

get_par_css_dataframe()

get a dataframe of composite scaled sensitivities. Includes both PEST-style and Hill-style.

Returns:

Type Description

pandas.DataFrame: a dataframe of parameter names, PEST-style and

Hill-style composite scaled sensitivity

reset_obscov(arg=None)

reset the obscov attribute to None

Parameters:

Name Type Description Default
arg `str` or `pyemu.Matrix`

the value to assign to the obscov attribute. If None, the private __obscov attribute is cleared but not reset

None

reset_parcov(arg=None)

reset the parcov attribute to None

Parameters:

Name Type Description Default
arg `str` or `pyemu.Matrix`

the value to assign to the parcov attribute. If None, the private __parcov attribute is cleared but not reset

None

reset_pst(arg)

reset the LinearAnalysis.pst attribute

Parameters:

Name Type Description Default
arg `str` or `pyemu.Pst`

the value to assign to the pst attribute

required