leizingjiu

if (numKeys > 1){ 

n=nearestKey(time).index; 

if(time<key(1).time){

  T=0;

 }else if(time>key(numKeys).time){

  T=0;

 }else if(time>key(1).time){ 

  if (key(n).time < time){

   n++;

  };

  V=valueAtTime(key(n))-valueAtTime(key(n-1));

  t=key(n).time-key(n-1).time;

  T=t/V;

 }else{0;}

}