Velocity Reviews > How do I get the trendline equation from Excel to script?

# How do I get the trendline equation from Excel to script?

Mattias
Guest
Posts: n/a

 12-07-2004
Hi!
I want to display a bargraph including a trendline on the Internet
(using an asp-page). It doesn't matter what I use to display it. I
have found some graph-components (for example FusionCharts 2.2) that
seems ok.

First: What is the easiest way to go?
1. Calculate the trendline values (with vbscript or javascript) and
using a graphcomponent
2. or using a excelcomponent and somehow manipulate it to show the
graphs (bargraph and trendline) that I want.

IF 1: Then the problem I have is that I can not figure out how to
calculate the trendline values.

I have found a page (http://www.j-walk.com/ss/excel/tips/tip101.htm)
that has some code used in Excel (see below). But the INDEX, LINEST
functions doesn't work in vbscript.
__________________________________________________ ____
Logarithmic Trendline
Equation: y = (c * LN(x)) - b

c: =INDEX(LINEST(y,LN(x)),1)

b: =INDEX(LINEST(y,LN(x)),1,2)

Power Trendline
Equation: y=c*x^b

c: =EXP(INDEX(LINEST(LN(y),LN(x),,),1,2))

b: =INDEX(LINEST(LN(y),LN(x),,),1)
__________________________________________________ ____

IF 2: I am not very used to excel-programming so how can I do this
trendline using a component? Oh, the person that will see this graph
does not have the excel program.

Best regards,
Mattias in Sweden