Arduino Due Unpredictable Analog Input Behavior

Official Hardware Mega Due
2

I would not do this:
unsigned int analogvalue4 = analogRead(A0);
unsigned int analogvalue5 = analogRead(A1);

You are assigning a default value with a parameter that is returned from a function. I would recommend:

unsigned int analogvalue4 ;
unsigned int analogvalue5 ;
analogvalue4 = analogRead(A0);
analogvalue5 = analogRead(A1);

Give it a try.