smx.plotting.threshold
======================

.. py:module:: smx.plotting.threshold

.. autoapi-nested-parse::

   plot_threshold_spectrum: visualise a multivariate threshold overlaid on
   the original spectral zone, coloured by class.

   Requires ``plotly``.  The dependency is optional — import errors produce a
   clear, actionable message rather than a hard package-load failure.



Functions
---------

.. autoapisummary::

   smx.plotting.threshold.plot_threshold_spectrum


Module Contents
---------------

.. py:function:: plot_threshold_spectrum(lrc_natural_df: pandas.DataFrame, row_index: int, spectral_zones_original: Dict[str, pandas.DataFrame], pca_info_dict_original: Dict, y_labels: pandas.Series, output_path: Optional[Union[str, pathlib.Path]], class_colors: Optional[Dict[str, str]] = None, theme: Optional[smx.plotting.theme.SMXTheme] = None, width: Optional[int] = 900, height: Optional[int] = 450, return_df: bool = False) -> Union[None, pandas.Series]

   Reconstruct a threshold to spectrum space and save an HTML plot.

   The plot overlays the reconstructed multivariate threshold (in red) on
   top of the individual sample spectra for the chosen spectral zone,
   coloured by class label. The figure is always displayed; set *return_df=True*
   to return the threshold spectrum Series.

   Parameters
   ----------
   lrc_natural_df : pd.DataFrame
       LRC DataFrame with natural-scale thresholds.  Must contain columns
       ``'Zone'``, ``'Threshold_Natural'``, and ``'Node_Natural'``.
   row_index : int
       Row of *lrc_natural_df* to visualise.
   spectral_zones_original : dict[str, pd.DataFrame]
       Spectral zones extracted from the *unpreprocessed* calibration data.
   pca_info_dict_original : dict
       PCA info from :class:`smx.zones.aggregation.ZoneAggregator` fitted on
       the natural (unpreprocessed) data.
   y_labels : pd.Series
       Class labels aligned with the calibration data rows.
   output_path : str or Path, optional
       Destination path for the output ``.html`` file.
       If ``None``, no file is written.
   class_colors : dict, optional
       Mapping of class label → colour string.  Explicit values override the
       theme.  Defaults to the theme's ``class_colors``.
   theme : SMXTheme, optional
       Visual theme.  Defaults to :data:`smx.plotting.theme.DEFAULT_THEME`.
   return_df : bool, default False
       If ``True``, return the threshold spectrum Series.

   Raises
   ------
   ImportError
       If ``plotly`` is not installed.