correction to allow negative mirror tuning

src/new/finesse/simulations/FT_finesse_beam_detection.m

@@ -49,7 +49,11 @@ function [beam] = FT_finesse_beam_detection(FT,katname,nodename,mirrorname,phi0,
     outbl(nb+1) = FT_add_line_to_block(outbl(nb+1),sprintf('beam beam0 0 %s',nodename));
     
     % Tune given mirror
+    if phi0>0
         outbl(nb+1) = FT_add_line_to_block(outbl(nb+1),sprintf('func tuning = %16.8f',phi0));
+    else
+        outbl(nb+1) = FT_add_line_to_block(outbl(nb+1),sprintf('func tuning = 0 - %16.8f',abs(phi0)));
+    end
     outbl(nb+1) = FT_add_line_to_block(outbl(nb+1),sprintf('put %s phi $tuning',mirrorname));
     
     % Add lines defining x and y axis