diff --git a/dap/algos/radprof.py b/dap/algos/radprof.py
index 8c0a5b5..3229ed9 100644
--- a/dap/algos/radprof.py
+++ b/dap/algos/radprof.py
@@ -24,18 +24,14 @@ def calc_radial_integration(results, data, pixel_mask):
     silent_min = results.get("radial_integration_silent_min", None)
     silent_max = results.get("radial_integration_silent_max", None)
 
-    if (
-        silent_min is not None and
-        silent_max is not None and
-        #TODO: skipping entirely is a guess, but not obvious -- better to ensure the order min < max by switching them if needed
-        silent_max > silent_min and
-        silent_min > r_min and
-        silent_max < r_max
-    ):
-        silent_region = rp[silent_min:silent_max]
-        integral_silent_region = np.sum(silent_region)
-        rp = rp / integral_silent_region
-        results["radint_normalised"] = [silent_min, silent_max]
+    if silent_min is not None and silent_max is not None:
+        # if start > stop, numpy returns an empty array -- better to ensure start < stop by switching them if needed
+        silent_min, silent_max = sorted((silent_min, silent_max))
+        if silent_min > r_min and silent_max < r_max:
+            silent_region = rp[silent_min:silent_max]
+            integral_silent_region = np.sum(silent_region)
+            rp = rp / integral_silent_region
+            results["radint_normalised"] = [silent_min, silent_max]
 
     results["radint_I"] = rp[r_min:].tolist() #TODO: why not stop at r_max?
     results["radint_q"] = [r_min, r_max]
diff --git a/dap/algos/roi.py b/dap/algos/roi.py
index ad45f8d..b44f241 100644
--- a/dap/algos/roi.py
+++ b/dap/algos/roi.py
@@ -25,7 +25,10 @@ def calc_roi(results, data):
     roi_intensities_proj_x = []
 
     for ix1, ix2, iy1, iy2 in zip(roi_x1, roi_x2, roi_y1, roi_y2):
-        #TODO: if start > stop, numpy returns an empty array, which is not obvious -- better to ensure the order start < stop by switching them if needed
+        # if start > stop, numpy returns an empty array -- better to ensure start < stop by switching them if needed
+        ix1, ix2 = sorted((ix1, ix2))
+        iy1, iy2 = sorted((iy1, iy2))
+
         data_roi = data[iy1:iy2, ix1:ix2]
 
         roi_sum = np.nansum(data_roi, dtype=float) # data_roi is np.float32, which cannot be json serialized
diff --git a/dap/algos/thresh.py b/dap/algos/thresh.py
index 631c568..bf84ed8 100644
--- a/dap/algos/thresh.py
+++ b/dap/algos/thresh.py
@@ -25,10 +25,10 @@ def threshold(data, vmin, vmax, replacement):
     """
     threshold data in place by replacing values < vmin and values > vmax with replacement
     """
+    # if vmin > vmax, data will be overwritten entirely -- better to ensure vmin < vmax by switching them if needed
+    vmin, vmax = sorted((vmin, vmax))
     data[data < vmin] = replacement
-    #TODO: skipping max is a guess, but not obvious/symmetric -- better to ensure the order min < max by switching them if needed
-    if vmax > vmin:
-        data[data > vmax] = replacement
+    data[data > vmax] = replacement