# skfolio.containers.Field2D ### *class* skfolio.containers.Field2D(values, \*, inactive_policy=MISSING) Numeric 2D field with axes (observations, assets). * **Parameters:** **values** *ndarray of shape (n_observations, n_assets)* : Numeric field values. Object dtype is rejected. Use `FieldCategorical` for categorical data. * **Attributes:** [`dtype`](#skfolio.containers.Field2D.dtype) : Dtype of the underlying values. **inactive_policy** [`is_3d`](#skfolio.containers.Field2D.is_3d) : Whether or not the field is a 3D field. [`is_categorical`](#skfolio.containers.Field2D.is_categorical) : Whether or not the field is a categorical field. [`missing_mask`](#skfolio.containers.Field2D.missing_mask) : Return a boolean mask indicating missing entries. [`n_assets`](#skfolio.containers.Field2D.n_assets) : Number of assets. [`n_observations`](#skfolio.containers.Field2D.n_observations) : Number of observations. [`ndim`](#skfolio.containers.Field2D.ndim) : Number of dimensions of the underlying values. [`shape`](#skfolio.containers.Field2D.shape) : Shape of the underlying values. **values** ### Methods | [`copy`](#skfolio.containers.Field2D.copy)(\*[, deep]) | Return a copy of the field. | |----------------------------------------------------------------------|----------------------------------------------------------| | [`with_values`](#skfolio.containers.Field2D.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. #### *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 entries. * **Returns:** **mask** *ndarray of bool* : Boolean array with the same shape as `values`. Entries are `True` where `values` is NaN for floating-point fields and `False` elsewhere. Non-floating fields without a missing-value convention return an all-`False` mask; subclasses override this method when they define their own convention. #### *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.