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02.20.2007 at 10:53AM PST, ID: 22401637
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Calculate logarithmic trendline equation

Asked by gammae in Probability & Statistics, PHP Scripting Language, Math & Science Questions

Tags: trendline, logarithmic, calculate, equation

I would like to accomplish in PHP something that easily done in Excel.

I have an array of data, I would like to calculate the Logarithmic trenline in order to graph it late ron.

I have found out that the equation of a logarithmic trendline is calculated in Excel using the following formulat:

Equation: y = (c * LN(x)) - b

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

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

How can I calculate b and c in PHP? I have not been able to find an equivalent of the INDEX and LINEAR function that is available in Excel.

Can ayone help me with that?

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[+][-]02.20.2007 at 12:30PM PST, ID: 18573676

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[+][-]02.20.2007 at 01:02PM PST, ID: 18573979

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Zones: Probability & Statistics, PHP Scripting Language, Math & Science Questions
Tags: trendline, logarithmic, calculate, equation
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Solution Provided By: ozo
Participating Experts: 2
Solution Grade: A
 
 
[+][-]02.20.2007 at 01:14PM PST, ID: 18574080

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[+][-]02.23.2007 at 04:37PM PST, ID: 18600372

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[+][-]02.23.2007 at 04:53PM PST, ID: 18600420

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[+][-]02.23.2007 at 05:27PM PST, ID: 18600533

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