monthly boxplot

I'm trying to make a monthly boxplot using this:

boxplot(varmeasure ~ vardates)

vardates = [1] 10/1/2010 10/1/2010 10/1/2010 10/1/2010 10/1/2010  
10/1/2010
10/1/2010
[8] 10/1/2010 10/1/2010 11/1/2010 11/1/2010 11/1/2010 11/1/2010  
11/1/2010
....

varmeasure =  [1]   0.0  26.0   0.2  -0.2  -1.2  -0.8   0.0   4.4   
-0.6
-0.2  14.4  -0.2
[13]   4.8   4.0   2.8   3.2   3.8   3.2 -11.4   0.2   0.4   3.0    
0.6   6.2
....


they have same size.


My problem is that R is ploting ordered by months and not by year  
and by
months

I'm getting 1/1/2011, 10/1/2010, 11/1/2010, 2/1/2011

How can I plot it in chronological order?

It worked, thanks.

Is there a way to put a trend line through the boxplots?

Hi, I got what I want using


lines(varmeasure ~ vardates)

but, as I'm using as.Date(vardates) in my boxplot code

boxplot(varmeasure ~ as.Date(vardate))

I want to change how vardate is displayed
I used strftime(as.Date(vardate), format="%m/%Y") and it worked well,
However it mixed the inital and final dates.

My data has measuraments from october 2010 to june 2011.

If I use  boxplot(varmeasure ~ as.Date(vardate)), data is displayed from
2010 to 2011.

if I use boxplot(varmeasure ~ strftime(as.Date(vardate), format="%m/%Y"))
data is displayed mixing 2010 and 2011 months in order to get jan to dez
display.


I need a way to keep my data display from oct 2010 to june 2011 but I also
need a way to change how X scale is displayed.

How can do it?

Thanks

On Tue, Aug 9, 2011 at 12:32 PM, David Winsemius<dwinsemius at comcast.net>wrote:

On Aug 9, 2011, at 10:17 AM, Fernando Andreacci wrote:

  It worked, thanks.

Is there a way to put a trend line through the boxplots?

You have not shown us how you set the data up or made the boxplots. A
"trend line through boxplots" seems be a bit ambiguous, since the x-variable
needs to be a factor and  a factor variable would not necessarily have
either a scale or an order. So the answer with the available information
cannot be anymore specific than "it depends".

--
David.

On Tue, Aug 9, 2011 at 10:58 AM, David Winsemius<dwinsemius at comcast.net

wrote:

On Aug 9, 2011, at 9:46 AM, Fernando Andreacci wrote:

I'm trying to make a monthly boxplot using this:

boxplot(varmeasure ~ vardates)

vardates = [1] 10/1/2010 10/1/2010 10/1/2010 10/1/2010 10/1/2010
10/1/2010
10/1/2010
[8] 10/1/2010 10/1/2010 11/1/2010 11/1/2010 11/1/2010 11/1/2010
11/1/2010
....

varmeasure =  [1]   0.0  26.0   0.2  -0.2  -1.2  -0.8   0.0   4.4  -0.6
-0.2  14.4  -0.2
[13]   4.8   4.0   2.8   3.2   3.8   3.2 -11.4   0.2   0.4   3.0   0.6
6.2
....


they have same size.


My problem is that R is ploting ordered by months and not by year and by
months

I'm getting 1/1/2011, 10/1/2010, 11/1/2010, 2/1/2011

How can I plot it in chronological order?

By converting those character strings to dates. At the moment you seem to
believe that R has the ability to "know" that you want these strings to
be
dates.

?as.Date
?Dates

--

David Winsemius, MD
West Hartford, CT

--
Fernando Andreacci
Bi?logo
Fone +55 47 9921 4015
       +55 41 9921 3934
fandreacci at gmail.com

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David Winsemius, MD
West Hartford, CT

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