diff --git a/matlab/TCV/gdat_tcv.m b/matlab/TCV/gdat_tcv.m
index f87d9e52c230fcf314a98a95c9ca08d17f9a57f5..b628185ac277d8e16c0d9a66cfb33aa19094c61b 100644
--- a/matlab/TCV/gdat_tcv.m
+++ b/matlab/TCV/gdat_tcv.m
@@ -3328,12 +3328,14 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
       end
       return
     end
+    % time_out: times at which to provide output data, if 2 values provided, return all values within that time interval
+    % for xtomo, can only provide a time interval, for radcam, can provide a time_out array on which interpos is computed
     time_interval = [];
     if isfield(gdat_data.gdat_params,'time_out') && ~isempty(gdat_data.gdat_params.time_out)
-      if length(gdat_data.gdat_params.time_out) == 2
+      if numel(gdat_data.gdat_params.time_out) == 2
         time_interval = gdat_data.gdat_params.time_out;
       else
-        if length(gdat_data.gdat_params.time_out) == 1
+        if numel(gdat_data.gdat_params.time_out) == 1
           % 200ms includes all characteristic time constants
           time_interval = [gdat_data.gdat_params.time_out-0.1 gdat_data.gdat_params.time_out+0.1];
         else