1 Equation for 4 variables

[afzalw]

Can I use excel to get make an equation for 4 variables (x,y,z,w)
e.g
a,b,c,d,3,f,g,h,i, would be constants

w = ax + by + cz + dx^2 + ey^2 + fz^2 + gxy + hyz + iyz
I tried regression but the equation looks like

w = ax + by + cz + c

Is it possible on ay other software e.g MATLAB

 

[pgc01]

... like the duplication of the yz term.

Funny how the eyes work. I was expecting

... gxy + hyz + ixz

and so that's what I read.

 

[afzalw]

I needed the offset in my equation, I just forgot to mention offset in equation of my first post and also did this duplication mistake. shg knew exactly what I required. So first equation with offset worked for me.

 

[shg]

To be clear, the order of coefficients is


...+ gxy + hxz + iyz + j