enh - make plotting functions return Figures and manage matplotlib more flexibly

- let user have control on the figure (add custom titles, axes)
- figures now allow the user to add them in subplots
- give user flexibility to choose if they want the figure to be shown (show_figure=True or False)
- fix plt.tight_layout() bug

Author: contsili

pcntoolkit/normative_model.py

@@ -14,6 +14,7 @@
 import numpy as np
 import scipy.stats as stats
 import xarray as xr
+import matplotlib.pyplot as plt
 
 from pcntoolkit.dataio.norm_data import NormData
 from pcntoolkit.math_functions.scaler import Scaler
@@ -162,12 +163,27 @@ def predict(self, data: NormData) -> NormData:
             data.save_results(resultsdir)
         if self.saveplots:
             plotdir = os.path.join(self.save_dir, "plots")
-            plot_qq(data, plot_id_line=True, save_dir=plotdir)
-            plot_centiles(
+
+            # QQ plots
+            for fig in plot_qq(
+                data,
+                plot_id_line=True,
+                save_dir=plotdir,
+                show_figure=False
+            ):
+                # Close all the figures after saving it to disk
+                plt.close(fig)
+
+            # Centiles plots
+            for fig in plot_centiles(
                 self,
                 data,
                 save_dir=plotdir,
-            )
+                show_figure=False,
+            ):
+                # Close all the figures after saving it to disk
+                plt.close(fig)
+
         return data
 
     def fit_predict(self, fit_data: NormData, predict_data: NormData) -> NormData: