fix: bug with background

- background cache was saved in both ptrms_lib and ptrms_lib interface

ptrms_lib @ 4789f4c1

-Subproject commit 55d2d345381e0e290b483a734742abe069807deb
+Subproject commit 4789f4c19fcc10741709922bf8555f630bc64a0a

src/algo/ptrms_lib.py

@@ -105,13 +105,17 @@ class ptrms_lib:
 
         # check if required info available to run code
         # ------------------------------------------------------------------------------
-        # background
-        if not self.bck_save.exists():
-            # if no cache background, we need to have blank in data
-            if not any(valve_data["meaning"] == "BLANK"):
-                raise RuntimeError(
-                    "No background data and no blank data in file. Impossible to process file."
-                )
+        # if no cache background, and no blank in data
+        filter_blank = valve_data["meaning"] == "BLANK"
+        if not self.bck_save.exists() and not any(filter_blank):
+            err_msg = "No background data and no blank data in file. Impossible to process file."  # noqa: E501
+            raise RuntimeError(err_msg)
+
+        # we need several points for blanks
+        n_blanks = filter_blank.to_numpy().astype(int).sum()
+        if n_blanks < 5:
+            print("not enough blanks. using cache background.")  # noqa: T201
+            ptrms_data_raw = ptrms_data_raw[~filter_blank]
 
         # processing to NCPS
         # ------------------------------------------------------------------------------
@@ -138,9 +142,6 @@ class ptrms_lib:
             self.bck_save,
         )
 
-        # save background
-        bck_data.to_csv(self.bck_save, float_format="%.3f")
-
         # get calibration coefficients
         # ---------------------------------------------------------------------------------
         snorm_data = calib.get_snorm(

tests/SIRTA/backgrounds/background_save.csv

-,mz_31,mz_33,mz_42,mz_45,mz_46,mz_47,mz_57,mz_58,mz_59,mz_60,mz_61,mz_63,mz_69,mz_71,mz_73,mz_75,mz_79,mz_81,mz_83,mz_85,mz_87,mz_93,mz_97,mz_99,mz_107,mz_111,mz_121,mz_137,mz_139,mz_147,mz_151
-2024-10-27 07:51:42.998400,7.6538724142195615,85.57709228262395,2.8615273473538423,18.92359024792213,,15.472185099450392,4.54505711405783,,5.305653723246409,,4.466380472078328,3.6350229217922827,3.1977896748722894,2.944168743054741,5.723146722987975,3.2179723310173665,2.778793923372653,,,,,6.000334133495124,,,4.746597324858441,,3.2476780114529196,2.539520394617266,,,