I'm programming a 10K thermistor with arduino duemilanove and processing to tweet the temperature every hour. The problem is that the example code that appears in the arduino site for the thermistor assumes that you have a 10K resistor so doing all the math will result in having the temperature in C°.
The problem is that i have only 12K resistors so i don't know how to calculate how much i must substract to the analog input value to get the temperature.
PS: Sorry for my english! I'm from Chile