Four Way Interpolation?

Dear community,

I am not really sure if the "name" of what I trying to do is what I typed in the title, but I don't know how else to word it...

So I have a set of data in the excel file attached, that basically has two parameters ZZ1 and ZZ2 that need to be calculated based on an interpolation of FOUR other parameters to the left.

I really don't know how to solve this, I would really appreciate it if someone could help me out.

Thank you so much!

Best regards,


ORLANDO

I know of no way to interpolate that, but you could regress it:

Row\Col	A	B	C	D	E	F	G	H	I
4		H	k2	A	k1	ZZ1	ZZ2
5		0.125	2	0.1	2	0.1980	0.4164
6		0.125	2	0.2	20	1.1849	0.4248
7		0.125	20	0.1	2	2.1180	0.6489
8		0.125	20	0.2	20	2.8979	0.9313
9		0.250	2	0.1	2	3.5026	1.5309
10		0.250	2	0.2	20	4.3691	2.3887
11		0.250	20	0.1	2	5.2799	2.6140
12		0.250	20	0.2	20	6.0313	3.0331
13
14
15		25.5682	0.098229	0	0.04701	-3.1940			B15:F15: {=LINEST(F$5:F$12, CHOOSE({1,2,3,4}, $E$5:$E$12, $D$5:$D$12, $C$5:$C$12, $B$5:$B$12))}
16		14.2906	0.034257	0	0.021774	-1.7973			B16:F16: {=LINEST(G$5:G$12, CHOOSE({1,2,3,4}, $E$5:$E$12, $D$5:$D$12, $C$5:$C$12, $B$5:$B$12))}
17
18		H	k2	A	k1	ZZ1	ZZ2
19	values from above >>	0.125	2	0.1	2	0.2926	0.1011		F19: =SUMPRODUCT($B$15:$E$15, $B19:$E19) + $F$15
20		0.125	2	0.2	20	1.1387	0.4930		G19: =SUMPRODUCT($B$16:$E$16, $B19:$E19) + $F$16
21		0.125	20	0.1	2	2.0607	0.7177
22		0.125	20	0.2	20	2.9069	1.1096
23		0.250	2	0.1	2	3.4886	1.8874
24		0.250	2	0.2	20	4.3348	2.2793
25		0.250	20	0.1	2	5.2567	2.5040
26		0.250	20	0.2	20	6.1029	2.8960
27
28	your new values >>	0.150	3.77	0.11	15	1.7167	0.8020

Hi and thank you so much for your response!

I have two quick questions:

1) I am not getting in my D15 cell the same value as you, you get 0, I get 8.46175 this is the formula I am using

=LINEST(F$5:F$12, CHOOSE(2, $E$5:$E$12, $D$5:$D$12, $C$5:$C$12, $B$5:$B$12))

entered as an array. I entered the number 4 in the choose() funciton in cell B15, the number 3 in the choose() function in cell C15, and the number 1 in the E15 cell... all of them yield the same number that you show. But for some reason I am not getting the D15 one.


2) How did you get the value in cell F15, I am not really sure how you got -3.1940 (which from reading the excel help would be the "b" constant, right?)

Thank you very much for you help sir!

Not

=LINEST(F$5:F$12, CHOOSE(2, $E$5:$E$12, $D$5:$D$12, $C$5:$C$12, $B$5:$B$12))

but

LINEST(F$5:F$12, CHOOSE({1,2,3,4}, $E$5:$E$12, $D$5:$D$12, $C$5:$C$12, $B$5:$B$12))

It's a single regression on four independent variables. Why not just use the formula as posted?

I apologize for the confusion. Thank you very much!

Please ignore the attached file below.

Thank you sir!

The LINEST formula is ONE formula array-entered across all five cells, not the same formula entered into each cell.

Select all five cells, press and hold the Ctrl and Shift keys, then press Enter.