Doing a project of a 3d surface chart to show the changing temperature from several sensors. The temperature data is retrieved from MySql database.  

I need help on manually assign the sensor data on certain coordinate. Eg. [x1,y1] - sensor1 , [x2,y1] -sensor 2, [x1,y2] - sensor3, [x2,y2]-sensor 4 , etc...
Any sample coding or guidance is appreciated.