How to plot a shifted Gamma distribution

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I have the parameters of a gamma distribution that I am trying to plot.
The parameters are shape = 2, scale = 5.390275 and the minimum value
x0 is 65.44945.

Since the gamma is shifted by x0, we have

Mean = shape*scale + x0 = 76.23
My question is, how can I do it in r?

I was trying to use dgamma function, but I saw no options to offset
the gamma distribution. I can only use the shape and scale parameters,
like this:

x <- seq(from=0, to=100, length.out=100)

plot(x, dgamma(x, shape=2, scale=5.390275),
      main="Gamma",type='l')
If all that is happening is that the distribution is the same as that
of a Gamma distribution with origin at 0, but simply shifted to the
right by an amount x0 (though I am wondering what context this could
arise in), then the commands

  x <- seq(from=0, to=100, length.out=100)
  x0 <- 65.44945
  plot(x+x0, dgamma(x, shape=2, scale=5.390275),
       main="Gamma",type='l')

will produce such a plot. However, I wonder if you have correctly
expressed the problem!

Ted.
This generates a distribution with origin equal zero, but I want the
origin to be x0

How can I handle shifted gamma distribution in r?

Thanks a lot!
Rodrigo.
-------------------------------------------------
E-Mail: (Ted Harding) <Ted.Harding at wlandres.net>
Date: 13-Feb-2014  Time: 17:27:29
This message was sent by XFMail
It is not hard to write your own function:

dsgamma <- function(x, x0=0, ...) {
  dgamma(x-x0,...)
}

and similar for the other functions.

You might also want to look at ?curve for plotting (your plotting is
fine, curve is just another option).

On Thu, Feb 13, 2014 at 8:30 AM, Rodrigo Cesar Silva
I have the parameters of a gamma distribution that I am trying to plot. The
parameters are shape = 2, scale = 5.390275 and the minimum value x0 is
65.44945.

Since the gamma is shifted by x0, we have

                Mean = shape*scale + x0 = 76.23

My question is, how can I do it in r?

I was trying to use dgamma function, but I saw no options to offset the
gamma distribution. I can only use the shape and scale parameters, like
this:

x <- seq(from=0, to=100, length.out=100)

plot(x, dgamma(x, shape=2, scale=5.390275),
     main="Gamma",type='l')

This generates a distribution with origin equal zero, but I want the origin
to be x0

How can I handle shifted gamma distribution in r?

Thanks a lot!

Rodrigo.

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