[Fix] merge_files

Fix for BeamSpectrumMonitor and BunchSpectrumMonitor with merge_files

tracking/monitors/tools.py

@@ -39,6 +39,9 @@ def merge_files(files_prefix, files_number, file_name=None):
     for group in list(f0):
         f.require_group(group)
         for dataset_name in list(f0[group]):
+            if dataset_name == "freq":
+                f0[group].copy(dataset_name, f[group])
+                continue
             shape = f0[group][dataset_name].shape
             dtype = f0[group][dataset_name].dtype
             shape_needed = list(shape)
@@ -60,6 +63,8 @@ def merge_files(files_prefix, files_number, file_name=None):
                 for n in range(n_slice):
                     slice_list.append(slice(None))
                 slice_list.append(slice(length*i,length*(i+1)))
+                if (dataset_name == "freq"):
+                    continue
                 if (dataset_name == "time") and (i != 0):
                     f[group][dataset_name][tuple(slice_list)] = f[group][dataset_name][(length*i) - 1] + fi[group][dataset_name]
                 else: