extrapolation using interp2 or any other function

I have a table of data with the following form(simplified ver.):

With some calcuation i compute a value of the 'red' data and 'yellow' data and i interpolate through this table to find the 'dark red' value using interp2. My problem is that sometimes the value computed for 'yellow' data is less than 0.01 or higher of 0.8 . So interpolation is not working.I know i can use spline but the values are not so accurate. Is there any way to extrapolate lineary??

Thanks in advance

Answer 1

[Star Strider]

The scatteredInterpolant function and its friends may do what you want.