feat: add fname kwarg to some plotting functions

src/invert4geom/plotting.py

@@ -208,6 +208,7 @@ def plot_cv_scores(
     param_name: str = "Hyperparameter",
     figsize: tuple[float, float] = (5, 3.5),
     plot_title: str | None = None,
+    fname: str | None = None,
 ) -> None:
     """
     plot a graph of cross-validation scores vs hyperparameter values
@@ -226,6 +227,8 @@ def plot_cv_scores(
         size of the figure, by default (5, 3.5)
     plot_title : str | None, optional
         title of figure, by default None
+    fname : str | None, optional
+        filename to save figure, by default None
     """
 
     sns.set_theme()
@@ -259,12 +262,16 @@ def plot_cv_scores(
 
     plt.tight_layout()
 
+    if fname is not None:
+        plt.savefig(fname)
+
 
 def plot_convergence(
     results: pd.DataFrame,
     params: dict[str, typing.Any],
     inversion_region: tuple[float, float, float, float] | None = None,
     figsize: tuple[float, float] = (5, 3.5),
+    fname: str | None = None,
 ) -> None:
     """
     plot a graph of L2-norm and delta L2-norm vs iteration number.
@@ -279,6 +286,8 @@ def plot_convergence(
         inside region of inversion, by default None
     figsize : tuple[float, float], optional
         width and height of figure, by default (5, 3.5)
+    fname : str | None, optional
+        filename to save figure, by default None
     """
 
     sns.set_theme()
@@ -357,6 +366,10 @@ def plot_convergence(
 
     plt.title("Inversion convergence")
     plt.tight_layout()
+
+    if fname is not None:
+        plt.savefig(fname)
+
     plt.show()