get temperature in the fixed point
 

hello guys:
i need get temperature in the fixed point(0.023,0.015). i take this way
if((sqrt(ND_SUM(pow(xc[0]-0.023,2.),pow(xc[1]-0.015,2.),0)))<.000000000001)
{ temp=C_T(c,t);
Message("temp=%1f\n",temp);
}
but this code doesn't work, the temperature is none. if the code is as follows:

temp=C_T(c,t);
Message("temp=%1f\n",temp);
if((sqrt(ND_SUM(pow(xc[0]-0.023,2.),pow(xc[1]-0.015,2.),0)))<.000000000001)
{
}
then i can get the temp ,but the temp is not correct.
please help me .i have no idea.