Functions > Data Analysis > Curve Fitting > Example: Thiele Interpolation and Regression
Example: Thiele Interpolation and Regression
Use the Thielecoeff and the Thiele functions can be considered a regression technique since the Thiele coefficients are extracted.
1. Enter a set of measured data representing the saturation temperature of boiling water in °C.
 P 0.1 0.5 1 2.5 5 10 25 50 100 150 200 220 bar T 45.81 81.32 99.61 127.41 151.84 179.89 223.96 263.94 311 342.16 365.75 373.71 °C
2. Use the Thiele method to interpolate a curve through the data set.
3. Use the polynomial regression method to interpolate a curve through the data set.
4. Plot the data set and the two interpolated curves.
5. Compare the calculated results returned by the Thiele method to two mid-points from the steam tables.
The calculated data points match the published data very closely.
6. Using the Thiele interpolated curve, calculate the temperature at which water boils in Mexico city 2250m above sea level.
Reference
The International Association for the Properties of Water and Steam, http://www.iapws.org