diff --git a/SP2XR_toolkit.py b/SP2XR_toolkit.py
index 3e19ec8..c4bb5a6 100644
--- a/SP2XR_toolkit.py
+++ b/SP2XR_toolkit.py
@@ -26,6 +26,7 @@ import ipywidgets as widgets
 from IPython.display import display, clear_output
 
 
+from matplotlib.backends.backend_pdf import PdfPages
 
 # %% Functions for listing files with specific string in name
 
@@ -1939,7 +1940,7 @@ def process_pbp_parquet(dir_path_pbp, dir_path_hk,
     ddf_hk['temporary_col'] = 1
 
     ddf_hk_1s = ddf_hk[['Sample Flow Controller Read (sccm)',
-                        'Sample Flow Controller Read (vccm)']].resample(dt_str).mean()
+                        'Sample Flow Controller Read (vccm)']].resample(dt_str).mean()  # do i need a fill na here?
     ddf_hk_1s[['original_idx']] = ddf_hk[['temporary_col']].resample(dt_str).count()
 
     ddf_hk_1s = ddf_hk_1s[ddf_hk_1s['original_idx'] != 0]
@@ -1971,10 +1972,11 @@ def process_pbp_parquet(dir_path_pbp, dir_path_hk,
     ddf_pbp_hk['S_numConc_within_range_std'] = ddf_pbp_hk['Scatt numb within range'] / (ddf_pbp_hk['Sample Flow Controller Read (sccm)'] * (dt/60))
     ddf_pbp_hk['S_numConc_within_range_vol'] = ddf_pbp_hk['Scatt numb within range'] / (ddf_pbp_hk['Sample Flow Controller Read (vccm)'] * (dt/60))
     
-    ddf_pbp['temporary_col'] = 1
+    
     
     
     # Calculate histograms of different classifications/flags:
+    ddf_pbp['temporary_col'] = 1
 
     dNdlogDmev, dMdlogDmev = process_hist_and_dist(ddf_pbp, 'BC mass within range', None, None, inc_mass_bin_lims, inc_mass_bin_ctrs, dt_str, flow=ddf_pbp_hk['Sample Flow Controller Read (vccm)'], rho_eff=rho_eff, BC_type=BC_type)
     dNdlogDmev_thin, dMdlogDmev_thin = process_hist_and_dist(ddf_pbp, 'BC mass within range', 'cnts_thin', 1, inc_mass_bin_lims, inc_mass_bin_ctrs, dt_str, flow=ddf_pbp_hk['Sample Flow Controller Read (vccm)'], rho_eff=rho_eff, BC_type=BC_type)
@@ -2150,4 +2152,23 @@ def raw_traces_plot(ch0_plot=[], ch1_plot=[],
 
     display(widgets.HBox([backward_button, forward_button]))
     interactive_plot = widgets.interactive(update_plot, event_index=event_slider)
-    display(interactive_plot)
\ No newline at end of file
+    display(interactive_plot)
+    
+    
+#%% Functions for plots
+
+
+def save_image(filename):
+    
+    with PdfPages(filename) as p:
+      
+        # get_fignums Return list of existing
+        # figure numbers
+        fig_nums = plt.get_fignums()  
+        figs = [plt.figure(n) for n in fig_nums]
+
+        # iterating over the numbers in list
+        for fig in figs: 
+
+            # and saving the files
+            fig.savefig(p, format='pdf') 
\ No newline at end of file