Interpolation within a data table

I have a 12 X 12 table of Z-values, which are found against variable P(1:1:12) and X(25:25:300) as shown in table.I want to get the value of "Z" @ P=10.5 & X=115 via interpolation. your help is appreciated.

[sixwwwwww]

You problem is not clear because if your first column is 1:1:12 then first element in table is 1 and if your first row is 100:25:300 then first element in table is 100. How you have two values at first element in table? Can you please share your table to find out solution

[Jan]

What exactly is "a table"?

[am]

Sorry, couldn't put it right. Here's the table and I have corrected my question too.

[sixwwwwww]

Hi can you send me the table?

[Image Analyst]

Something is still not correct, despite your claim to have edited it to fix in. You say that the first column is x and is 100:25:300. Yet it seems to be 25:25:300 instead, since the numbers start at 25, not 100. Also the table is 13 columns if the first columns is X and there are 12 columns in addition to that. And if the first row is P and there are 12 rows in addition to that, then there are 13 rows, not 12. So is X and P actually columns/rows in the table as you said? Or are they separate column/row vectors and not part of the 12x12 table?

[am]

Pardon my ignorance, actually this is some experimental data & yes; X=(25:25:300) and P=1:1:12. The Z values are found against these two variables which is 12x12 table of Z values. So you can say X & P are separate column/row vectors (reference values for Z).

Answer 1

[Image Analyst]

Why not just use bilinear interpolation: http://en.wikipedia.org/wiki/Bilinear_interpolation. It's easy, intuitive, and straightforward.

[am]

I'll give it a try and let you know!