VBa code for index(linest)

[nitn28]

hi everyone

i m trying to write vba code to get coeefiecints of second order
polynomial eequation



Equation: y = (c2 * x^2) + (c1 * x ^1) + b

c2: =INDEX(LINEST(y,x^{1,2}),1)

C1: =INDEX(LINEST(y,x^{1,2}),1,2)

b = =INDEX(LINEST(y,x^{1,2}),1,3)

ihave recorded macro

Cells(j + 2, "D").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-2]:R[2]C[-2],RC[-3]:R[2]C[-3]^{1,2}),1)"
Cells(j + 2, "E").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-3]:R[2]C[-3],RC[-4]:R[2]C[-4]^{1,2}),1,2)"
Cells(j + 2, "F").Select
ActiveCell.FormulaR1C1 = _
"=INDEX(LINEST(RC[-4]:R[2]C[-4],RC[-5]:R[2]C[-5]^{1,2}),1,3)"

but now trying to write VBA CODE for NROWS,NCOLUMNNS]

i hop i wil get direction from this group
many thanks in advance 4 ur efrts n time

 

[Jon Peltier]

Why not use this as your formula:

Cells(j + 2, "D").Resize(,3).FormulaArray =
"=LINEST(RC[-2]:R[2]C[-2],(RC[-3]:R[2]C[-3])^{1,2})"

What exactly are the NROWS and NCOLUMNS you want? NRows I guess is the span
from R to R[2], so if you define a Long or Int variable nRows, the right
part of the above becomes:

"=LINEST(RC[-2]:R[" & nRows - 1 & "]C[-2],(RC[-3]:R[" & nRows - 1 &
"]C[-3])^{1,2})"

I don't know how you'd use nColumns in this context.

- Jon

 

[nitn28]

What exactly are the NROWS and NCOLUMNS you want? NRows I guess is the span
from R to R[2], so if you define a Long or Int variable nRows, the right
part of the above becomes:

thanx Mr. Jon for ur time n effort

wel by nrows and n columns i mean

i want to calculate equation coefficients for unknown set of X,y data

plz stil if its unclear plz let me know

many thanxin advance