diff --git a/matlab/TCV/gdat_tcv.m b/matlab/TCV/gdat_tcv.m
index 60fba66320f0f88663a091f03d645da9116931ab..ef503dc46e61947ac144d6e5c21ff0aa4948970c 100644
--- a/matlab/TCV/gdat_tcv.m
+++ b/matlab/TCV/gdat_tcv.m
@@ -3560,7 +3560,7 @@ elseif strcmp(mapping_for_tcv.method,'switchcase')
         % invert index of time and channel (rho)
         gdat_data.data = mpx.(gdat_data.gdat_params.camera(1:3)).signal.data';
         gdat_data.t = mpx.(gdat_data.gdat_params.camera(1:3)).signal.dim{1};
-        gdat_data.dim{1} = interpos_nan(21,mpx.top.rho.time,mpx.top.rho.rhopsi,gdat_data.t)';
+        gdat_data.dim{1} = interp1(mpx.top.rho.time,mpx.top.rho.rhopsi,gdat_data.t)';
         gdat_data.dim{2} = mpx.(gdat_data.gdat_params.camera(1:3)).signal.dim{1};
         gdat_data.x = gdat_data.dim{1};
         gdat_data.(gdat_data.gdat_params.camera).data = gdat_data.data;