You could create a simple function to change the preference. You could even have that function retrieve the current value and set the preference to the other value (to toggle it.)
syms x
for k = 1:5
toggleFPO
queryFPO
y = expand((x*k).^(1/3))
end
function toggleFPO
sympref('FloatingPointOutput', ~sympref('FloatingPointOutput'));
end
function queryFPO
if sympref('FloatingPointOutput')
fprintf('FloatingPointOutput is enabled.\n')
else
fprintf('FloatingPointOutput is disabled.\n')
end
end
