# skfolio.containers.FieldCategorical ### *class* skfolio.containers.FieldCategorical(values, levels, \*, inactive_policy=MISSING) Integer-coded categorical 2D field. Codes are stored as integers in a 2D array with axes (observations, assets). Code -1 is reserved for missing values. Code 0 selects `levels[0]`, code 1 selects `levels[1]` and so on. * **Parameters:** **values** *integers ndarray of shape (n_observations, n_assets)* : Integer category codes. Missing values must be encoded with `MISSING_CATEGORY_CODE`. **levels** *ndarray of shape (n_levels,)* : Category labels selected by codes 0, 1 and so on. Labels must be unique. * **Attributes:** [`dtype`](#skfolio.containers.FieldCategorical.dtype) : Dtype of the underlying values. **inactive_policy** [`is_3d`](#skfolio.containers.FieldCategorical.is_3d) : Whether or not the field is a 3D field. [`is_categorical`](#skfolio.containers.FieldCategorical.is_categorical) : Whether or not the field is a categorical field. **levels** [`missing_mask`](#skfolio.containers.FieldCategorical.missing_mask) : Return a boolean mask indicating missing categorical codes. [`n_assets`](#skfolio.containers.FieldCategorical.n_assets) : Number of assets. [`n_observations`](#skfolio.containers.FieldCategorical.n_observations) : Number of observations. [`ndim`](#skfolio.containers.FieldCategorical.ndim) : Number of dimensions of the underlying values. [`shape`](#skfolio.containers.FieldCategorical.shape) : Shape of the underlying values. **values** ### Methods | [`copy`](#skfolio.containers.FieldCategorical.copy)(\*[, deep]) | Return a copy of the field. | |------------------------------------------------------------------------------|----------------------------------------------------------| | [`decode`](#skfolio.containers.FieldCategorical.decode)(\*[, missing_label]) | Decode integer codes to level labels. | | [`with_values`](#skfolio.containers.FieldCategorical.with_values)(values) | Return a field of the same type with replacement values. | #### copy(\*, deep=False) Return a copy of the field. * **Parameters:** **deep** *bool, default=False* : If `True`, copy NumPy arrays stored by the field. If `False`, reuse the same array objects. * **Returns:** **field** *BaseField* : Field instance of the same concrete class. #### decode(\*, missing_label='MISSING') Decode integer codes to level labels. * **Parameters:** **missing_label** *str, default=”MISSING”* : Label assigned to missing or out-of-bound codes. * **Returns:** **decoded** *ndarray* : Decoded labels with the same shape as `values`. #### *property* dtype Dtype of the underlying values. #### *property* is_3d Whether or not the field is a 3D field. #### *property* is_categorical Whether or not the field is a categorical field. #### *property* missing_mask Return a boolean mask indicating missing categorical codes. * **Returns:** **mask** *ndarray of bool* : Boolean array with the same shape as `values`. Entries are `True` where `values` equals `MISSING_CATEGORY_CODE`. #### *property* n_assets Number of assets. #### *property* n_observations Number of observations. #### *property* ndim Number of dimensions of the underlying values. #### *property* shape Shape of the underlying values. #### with_values(values) Return a field of the same type with replacement values. Metadata arrays are reused. The replacement values are validated by the concrete field class constructor. * **Parameters:** **values** *array-like* : Replacement field values. * **Returns:** **field** *BaseField* : Field instance of the same concrete class.