class_docstr: Create plots for `PDPIsolate`
  
  Methods
  -------
  plot : generate the plot
  plot_matplotlib : plot using matplotlib
  plot_plotly : plot using plotly
class_docstr_tok: ["Create","plots","for","`","PDPIsolate","`","Methods","--","--","--","-","plot",":","generate","the","plot","plot_matplotlib",":","plot","using","matplotlib","plot_plotly",":","plot","using","plotly"]
code: def _prepare_pdp_line_data(self, class_idx):
      pdp_result = self.plot_obj.results[class_idx]
      pdp, ice_lines = (
          pdp_result.pdp.copy(),
          pdp_result.ice_lines.copy(),
      )
      feat_grids = self.plot_obj.feature_info.grids
      grid_indices = np.arange(len(feat_grids))
  
      x = (
          feat_grids
          if self.is_numeric and not self.plot_style.to_bins
          else grid_indices
      )
  
      if self.plot_style.center:
          pdp -= pdp[0]
          for i in np.arange(1, len(feat_grids)):
              ice_lines[i] -= ice_lines[0]
          ice_lines[0] = 0
  
      line_data = None
      if self.plot_style.plot_lines:
          line_data = (
              self._cluster_ice_lines(ice_lines, feat_grids)
              if self.plot_style.clustering["on"]
              else self._sample_ice_lines(ice_lines)
          )
  
      line_std = ice_lines[grid_indices].std().values
  
      return x, pdp, line_data, line_std
  
imports: from .utils import _get_string, _to_rgba
  from .styles import _prepare_plot_style, _axes_modify, _display_percentile, _modify_legend_axes, _get_axes_label
  import pandas
  import numpy
  import matplotlib
  import matplotlib.pyplot
  from matplotlib.gridspec import GridSpecFromSubplotSpec
  import copy
  from mpl_toolkits.axes_grid1.inset_locator import inset_axes
  import plotly.graph_objects
  from sklearn.cluster import MiniBatchKMeans, KMeans
  from itertools import cycle
label_desc: Use image node_id 5 for calling the PDPIsolatePlotEngine obj's underlying member method code with example usage: obj._prepare_pdp_line_data(class_idx) and returns: x,  pdp,  line_data,  line_std