added boolean copy switch

dap/algos/thresh.py

@@ -2,14 +2,14 @@ import numpy as np
 
 
 #TODO: this is duplicated in calc_radial_integration and calc_apply_aggregation
-def calc_apply_threshold(results, data):
+def calc_apply_threshold(results, data, copy=False):
     apply_threshold = results.get("apply_threshold", False)
     if not apply_threshold:
-        return
+        return data
 
     for k in ("threshold_min", "threshold_max"):
         if k not in results:
-            return
+            return data
 
     threshold_value_choice = results.get("threshold_value", "NaN")
     threshold_value = 0 if threshold_value_choice == "0" else np.nan #TODO
@@ -17,8 +17,13 @@ def calc_apply_threshold(results, data):
     threshold_min = float(results["threshold_min"])
     threshold_max = float(results["threshold_max"])
 
+    if copy:
+        data = data.copy() # do the following in-place changes on a copy
+
     threshold(data, threshold_min, threshold_max, threshold_value)
 
+    return data
+
 
 
 def threshold(data, vmin, vmax, replacement):