arviz_base.dataset_to_dataarray

arviz_base.dataset_to_dataarray(ds, sample_dims=None, labeller=None, add_coords=True, new_dim='label', label_type='flat')

Convert a Dataset to a stacked DataArray, using a labeller to set coordinate values.

Parameters:

dsxarray.Dataset

Input data

sample_dimssequence of hashable, optional

Dimensions that are present in all variables of ds and should be kept in the returned DataArray. All other variables will be stacked into new_dim.

labellerlabeller, optional

Labeller instance with a make_label_flat or make_label_vert method that will be use to generate the coordinate values along new_dim.

add_coordsbool, default True

Return multiple coordinate variables along new_dim. These will contain the newly generated labels, the stacked variable names, and stacked coordinate values.

new_dimhashable, default “label”

Name of the new dimension that is created from stacking variables and dimensions not in sample_dims.

label_type{“flat”, “vert”}, default “flat”

if “flat”, then labeller.make_label_flat method is used to generate the labels and if “vert”, then labeller.make_label_vert method is used.

Returns:

xarray.DataArray

Examples

Convert the posterior group into a stacked and labelled dataarray:

import xarray as xr
from arviz_base import load_arviz_data, dataset_to_dataarray
xr.set_options(display_expand_data=False)

idata = load_arviz_data("centered_eight")
dataset_to_dataarray(idata.posterior.dataset)

<xarray.DataArray 'mu' (chain: 4, draw: 500, label: 10)> Size: 160kB
7.872 12.32 9.905 14.95 11.01 5.58 16.9 ... 6.849 1.86 7.936 6.762 1.295 4.461
Coordinates:
  * chain     (chain) int64 32B 0 1 2 3
  * draw      (draw) int64 4kB 0 1 2 3 4 5 6 7 ... 493 494 495 496 497 498 499
  * label     (label) <U23 920B 'mu' 'theta[Choate]' ... 'tau'
  * variable  (label) <U5 200B 'mu' 'theta' 'theta' ... 'theta' 'theta' 'tau'
  * school    (label) object 80B nan 'Choate' 'Deerfield' ... 'Mt. Hermon' nan

xarray.DataArray

'mu'

• chain: 4
• draw: 500
• label: 10

• 7.872 12.32 9.905 14.95 11.01 5.58 ... 1.86 7.936 6.762 1.295 4.461

  array([[[ 7.87179637, 12.32068558,  9.90536689, ..., 13.19805933,
           15.06136584,  4.72574006],
          [ 3.38455431, 11.28562322,  9.12932369, ..., 10.05522282,
            6.17672421,  3.90899361],
          [ 9.10047569,  5.70850575,  5.7579324 , ...,  7.60475341,
            8.76764689,  4.8440252 ],
          ...,
          [ 3.65680422, -0.21382811,  1.35515489, ...,  4.93020022,
            3.05860034,  1.89383828],
          [ 5.42727938, 10.40250133,  6.90740688, ...,  5.3910607 ,
            6.38123908,  5.92006245],
          [ 2.73588293,  6.66130764,  7.41376703, ...,  7.56657019,
            9.98761823,  4.32589567]],
  
         [[ 4.31581657,  5.59663866,  6.95960523, ...,  7.14885429,
            3.79090016,  1.97083011],
          [ 4.59770112,  4.96540992,  1.77935809, ...,  3.28916128,
            5.93731077,  2.04902913],
          [ 6.21376164,  5.89670043,  9.47253003, ...,  3.30221324,
            7.16213323,  2.12376496],
  ...
          [ 2.87106698,  4.71860289,  6.3386488 , ...,  7.29157333,
           -0.10026455,  4.08978031],
          [ 4.09553646,  5.67765139,  1.67910823, ...,  1.28061498,
            7.62765755,  2.72016996],
          [ 1.77571755,  1.62544668,  2.50328085, ...,  2.36275624,
           -2.96799418,  1.91701121]],
  
         [[ 7.17950438,  8.34450834,  5.39085524, ..., 12.46813994,
           12.60779651,  6.07325982],
          [ 6.53969896,  8.93115045,  6.85296853, ...,  7.01397138,
            5.13629724,  3.77186702],
          [ 7.48361981,  9.62317435,  5.10464403, ...,  9.45569534,
            8.85937825,  3.17053747],
          ...,
          [ 1.76673325,  3.53251469,  2.00890089, ...,  3.07331446,
           -2.62306892,  2.74060666],
          [ 3.48611194,  4.1827505 ,  7.55425055, ...,  1.09609826,
            8.45228161,  2.93237926],
          [ 3.40446391,  0.19295578,  6.4984278 , ...,  6.76245459,
            1.2950506 ,  4.46124596]]], shape=(4, 500, 10))

• Coordinates: (5)
  • chain
    (chain)
    int64
    0 1 2 3

    array([0, 1, 2, 3])

  • draw
    (draw)
    int64
    0 1 2 3 4 5 ... 495 496 497 498 499

    array([  0,   1,   2, ..., 497, 498, 499], shape=(500,))

  • label
    (label)
    <U23
    'mu' 'theta[Choate]' ... 'tau'

    array(['mu', 'theta[Choate]', 'theta[Deerfield]', 'theta[Phillips Andover]',
           'theta[Phillips Exeter]', 'theta[Hotchkiss]', 'theta[Lawrenceville]',
           "theta[St. Paul's]", 'theta[Mt. Hermon]', 'tau'], dtype='<U23')

  • variable
    (label)
    <U5
    'mu' 'theta' ... 'theta' 'tau'

    array(['mu', 'theta', 'theta', 'theta', 'theta', 'theta', 'theta', 'theta',
           'theta', 'tau'], dtype='<U5')

  • school
    (label)
    object
    nan 'Choate' ... 'Mt. Hermon' nan

    array([nan, 'Choate', 'Deerfield', 'Phillips Andover', 'Phillips Exeter',
           'Hotchkiss', 'Lawrenceville', "St. Paul's", 'Mt. Hermon', nan],
          dtype=object)

• Indexes: (5)
  • chain
    PandasIndex

    PandasIndex(Index([0, 1, 2, 3], dtype='int64', name='chain'))

  • draw
    PandasIndex

    PandasIndex(Index([  0,   1,   2,   3,   4,   5,   6,   7,   8,   9,
           ...
           490, 491, 492, 493, 494, 495, 496, 497, 498, 499],
          dtype='int64', name='draw', length=500))

  • label
    PandasIndex

    PandasIndex(Index(['mu', 'theta[Choate]', 'theta[Deerfield]', 'theta[Phillips Andover]',
           'theta[Phillips Exeter]', 'theta[Hotchkiss]', 'theta[Lawrenceville]',
           'theta[St. Paul's]', 'theta[Mt. Hermon]', 'tau'],
          dtype='object', name='label'))

  • variable
    PandasIndex

    PandasIndex(Index(['mu', 'theta', 'theta', 'theta', 'theta', 'theta', 'theta', 'theta',
           'theta', 'tau'],
          dtype='object', name='variable'))

  • school
    PandasIndex

    PandasIndex(Index([               nan,           'Choate',        'Deerfield',
           'Phillips Andover',  'Phillips Exeter',        'Hotchkiss',
              'Lawrenceville',       'St. Paul's',       'Mt. Hermon',
                          nan],
          dtype='object', name='school'))

• Attributes: (0)