R help - May 2011 - histogram with density

Hello All,*

*I want to draw a histogram with density curve. *

*For that simply i created a data called*"x" *and i used the function
called
*    hist(x, col = "blue", freq = FALSE),**   *from this function i
got a
histogram*.

*After that , i tried this function*  ** lines(density(x), col =
"red", lwd
= 2  )  *but i could not get the density curve.

So, Again i used  other function*    curve(dnorm, col = 2, add = TRUE)**
*instead of the previous function for density curve.

but still am getting error in R  like this:

  Error in plot.xy(xy.coords(x, y), type = type, ...)
  plot.new has not been called yet"


*  I have used below codes to have a data and histogram with density curve"

x <- rnorm(200)
hist(x, col = "blue", freq = FALSE)
lines(density(x), col = "red", lwd = 2)
*
or

* x <- rnorm(200);
 hist(x, freq = FALSE, col = "grey");
 curve(dnorm, col = 2, add = TRUE)
*

please give your valuable inputs


Thanks in advance...

-- 
*Best Regards,
Reka.


*

	[[alternative HTML version deleted]]

Hi,

On Mon, May 23, 2011 at 11:41 PM, Rekha <chithralekha86 at gmail.com>
wrote:
> Hello All,*
>
> *I want to draw a histogram with density curve. *
>
> *For that simply i created a data called*"x" *and i used the
function called
> * ? ?hist(x, col = "blue", freq = FALSE),** ? *from this function
i got a
> histogram*.
>
> *After that , i tried this function* ?** lines(density(x), col =
"red", lwd
> = 2 ?) ?*but i could not get the density curve.
>
> So, Again i used ?other function* ? ?curve(dnorm, col = 2, add = TRUE)**
> *instead of the previous function for density curve.
>
> but still am getting error in R ?like this:
>
> ?Error in plot.xy(xy.coords(x, y), type = type, ...)
> ?plot.new has not been called yet"
>
>
> * ?I have used below codes to have a data and histogram with density
curve"
>
> x <- rnorm(200)
> hist(x, col = "blue", freq = FALSE)
> lines(density(x), col = "red", lwd = 2)
You should use the code above.

I don't get it though -- this is working fine for me. Are you getting
the "plot.new" error for both versions of your code?

Although I feel like in 99% of the time this won't be necessary, but
what happens if you call `plot.new()` before your call to hist?

eg:

R> x <- rnorm(200)
R> plot.new()
R> hist(x, col = "blue", freq = FALSE)
R> lines(density(x), col = "red", lwd = 2)

Does that work? If not -- what if you use `dev.new()` in place of `plot.new()`?

-steve

-- 
Steve Lianoglou
Graduate Student: Computational Systems Biology
?| Memorial Sloan-Kettering Cancer Center
?| Weill Medical College of Cornell University
Contact Info: http://cbio.mskcc.org/~lianos/contact