# interpolate measured data

• Nov 10th 2005, 01:28 PM
jhasting
interpolate measured data
I have a measured data set (x & y are inputs, z is the result at those measures):

x y z
0.036802 0.004908 0.07158
0.036802 0.022135 0.10095
0.130886 0.004908 0.09627
0.130886 0.022135 0.12560

I would like a formula for interpolation, to predict z for all input conditions x & y (within bounds), for example when x=0.0875 & y=0.0066.

I have tried some some formulas, but nothing is predicting with much accuracy.

Thanks for any help
J
• Nov 15th 2005, 05:18 PM
hpe
Quote:

Originally Posted by jhasting
I have a measured data set (x & y are inputs, z is the result at those measures):

x y z
0.036802 0.004908 0.07158
0.036802 0.022135 0.10095
0.130886 0.004908 0.09627
0.130886 0.022135 0.12560

I would like a formula for interpolation, to predict z for all input conditions x & y (within bounds), for example when x=0.0875 & y=0.0066.

I have tried some some formulas, but nothing is predicting with much accuracy.

Thanks for any help
J

The four data points you have there may be interpolated exactly with a function of the form \$\displaystyle z = a + bx + cy + dxy\$. Plug in the four data points and solve for a, b, c, d.