[R-sig-eco] Basic question about summary interpretation

[Luis Fernando García]

Dear R fellows,

I am sorry if my question is too basic (for most of you it might be) but
there is something which always gets me a bit confused when using R.

This time I am making an exercise where I have to find the slope and
intercept of two hypothetical lines which are being compared by using the
summary The information I have is attached in the summary below.I want 1)
to find the slopes value and 2) find out if I can get one intercept value
for each line. All of this using the summary only.

I know I can estimate the slopes by adding its estimated value to the
intercept. But the second question is the one which confuses me more, is it
possible to get an intercept value for each line using this info, do they
have a common intercept? If they have a commo intercept, to get its value
for each line, would it be necessary to make a single regression per line,
is there another way to do it?

Again, I am sorry if my question is too basics or fool, but this is a doubt
I would like to clarify. Any infomation or reply will be welcome!

Thanks!

Call:
glm(formula = C1 ~ I(1/D) + P, family = Gamma,
    data = dat)

Deviance Residuals:
     Min        1Q    Median        3Q       Max
-0.81738  -0.17791  -0.00102   0.15714   0.78180

Coefficients:
                  Estimate Std. Error t value Pr(>|t|)
(Intercept)        0.21966    0.01859  11.815 1.56e-15 ***
I(1/D)             0.20793    0.04242   4.902 1.22e-05 ***
Ps                -0.06703    0.02013  -3.330  0.00172 **
---
Signif. codes:  0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1

(Dispersion parameter for Gamma family taken to be 0.08774536)

    Null deviance: 7.8895  on 48  degrees of freedom
Residual deviance: 4.2584  on 46  degrees of freedom
AIC: 162.32

Number of Fisher Scoring iterations: 5

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