# Re: Access coefficients in trendline

• From: Jean Brefort <jean brefort normalesup org>
• To: Mike Simms <mesimms gmail com>
• Cc: gnumeric-list gnome org
• Subject: Re: Access coefficients in trendline
• Date: Mon, 05 Nov 2012 16:32:19 +0100

```Le lundi 05 novembre 2012 à 05:29 -0800, Mike Simms a écrit :
```
```Hi Jean,

You say "you can evaluate them with the linest function (you need a column
for each power of the x values)." That sounds good, but reading section
5.2.4.5. of the manual, "Array Formulas", I don't understand what is meant.
does it mean, if my 'y' data is a1:a100 and my 'x' data is in b1:b100, and I
want a 3rd order polynomial, it sounds like I should try to get
={linest(a1:a100Wind,b1:b100,TRUE)}(1,3)[0][0]
={linest(a1:a100Wind,b1:b100,TRUE)}(1,3)[0][1]
={linest(a1:a100Wind,b1:b100,TRUE)}(1,3)[0][2]
```
```I don't understand the Wind thing above.

You might add x^2 in column c and x^3 in d, then the formula is
=linest(a1:a100;b1:d100,TRUE)
you need to enter this formula as an array formula in four consecutive
cells in a row. The inidces are automatically added, you can't change
them.

Hope this helps.
Jean

```
```in three cells.
I can type
=linest(a1:a100Wind,b1:b100,TRUE)
in one cell, press Ctrl+Shift+Enter and the cells contents change to
={linest(a1:a100Wind,b1:b100,TRUE)}(1,1)[0][0]
but how do I change the (1,1)[0][0] section? Or am I way off?

Regards,
Mike

```
```

```