R help - Jul 2010 - calculate slope of line

Dear All,

I fear that this is a really easy question but I do seem to go around in 
circles..
I have 2 points on a plot and would like to calculate the slope of the 
line drawn through these 2 points.

that cant be so hard?!

Thank you in advance,
Katrin

-- 
Katrin Fleischer
Vrije Universiteit Amsterdam
Faculty of Earth and Life Sciences
Subdepartment Hydrolgy and Geo-Environmental Sciences
Room E-360
De Boelelaan 1085
1081 HV AMSTERDAM
Tel: +31 20 59 87391

On 23-Jul-10 09:46:28, Katrin Fleischer wrote:
> Dear All,
> I fear that this is a really easy question but I do seem to go
> around in circles..
> I have 2 points on a plot and would like to calculate the slope
> of the line drawn through these 2 points.
> 
> that cant be so hard?!
> 
> Thank you in advance,
> Katrin
  (y2 - y1)/(x2-x1)

or, if X=c(x1,x2) and Y=c(y1,y2),

  diff(Y)/diff(X)

either of which is shorter than

  lm(Y ~ X)$coeff[2]              ##  !! :)

Ted.

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Date: 23-Jul-10                                       Time: 12:10:24
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