Extrapolate values for a variable that is dependent on three other variables?

I have data downloaded for three variables:

• Temperature (85x1)
• Salinity (85x1)
• Pressure (85x1)

I use the three variables to calculate Density through a function I downloaded. I have 107 files all with the same variables but with varying lengths, so the shortest file has dimensions (85x1) while the longest has dimensions (3061x1). How can I extrapolate the values if its dependent on three different variables?

[KSSV]

What is the dependent variable here? The dimensions 85X1 and 3061X1 are wrt to what? Time?

[Shayma Al Ali]

The dependent variable is Density. The dimensions are reference to depth.

Answer 1

[Walter Roberson]

Use your vectors of representative datas to calculate corresponding representive densities. Then

F = scatteredInterpolant(Temperature, Salinity, Pressure, calculated_Density);

After that, you can

interpolated_Density = F(query_temperature, query_salinity, query_pressure)