How to use curve fitting toolbox for 4d curve f=function(x,y,z,t)

I have a set of points for f which is dependant on 3 variables x,y,z,t. I need to get a function for f which will best fit its surface plot. Curve fitting toolbox allows only 3d variables. Is there a means to increase the no.of axes of the toolbox? The dataset is as given below.

x = [25,0,-10,-25];
y = [0.4,0.6,1.0];
t = [-1,1];
f =[0.000619439699096160,4.848196652132607E-4,0.000607798163756881,4.895978639282532E-4,0.00318734657728198,0.001184857511615985,0,0,0.00129642201525071,5.32063357274609E-4,0.00165368839952746,0.007273340507576425,0,0,0.00239746199392812,1.1633603182305461E-8,0,0,0.00332800201586229,0.013144175879650886,0.00314257470466464,9.919148284952006E-5,0.00376067372689167,0.013924965429810449];