[R] Create histogram from data matrix

[Paul Warren Simonin]

Thank you all for your advice.
   I have received some good tips, but it was suggested I write back  
with a small simulated data set to better illustrate my needs. So,  
currently my data frame looks something like:

ID (date)  Temperature	Number of fish
200706183	5	456
200706183	5	765
200706183	4	567
200706183	3	876
200706183	3	888
200706183	2	111
200706184	8	2345
200706184	8	654
200706184	8	7786
200706184	7	345
200706184	6	234
200706184	6	123


I need to create a plots for each ID (date) of the number of fish  
observed at each temperature. Obviously my data frame is much larger.  
These plots do not have to be in a specific histogram format, but it  
seems this may be appropriate.
Thanks for any additional advice as to how this may be done, either  
using plot commands or reformatting my data.

It seemed the ggplot2 options may be good but so far I have tried  
qplot with no success:

my most recent code looks like:

qplot(temp,number of fish, geom="histogram",binwidth=1)

I have tried various tweaks of this, but no success.

Thanks for any advice!
-Paul Simonin


Quoting stephen sefick <ssefick at gmail.com>:

> It would be easier if you were to make a data frame of fake values to
> illustrate your point, so that we could just copy it into an R session
> and see if we can't get it to work.  So, a stab in the dark would to
> look at ggplot2 specifically the hist argument in qplot and the
> facets, the lattice package, or reshape to change the format of your
> data. If you want me to fool around with it use dput and take a small
> subset of your data or make up data to be able to be copied into an R
> session.
> hope that helps,
>
> Stephen
>
> On Fri, Apr 17, 2009 at 10:59 AM, Paul Warren Simonin
> <Paul.Simonin at uvm.edu> wrote:
>> Hello!
>>  Thanks for reading this request for assistance. I have a question regarding
>> creating a histogram-like figure from data that are not currently in the
>> correct format for the "hist" command.
>>  Specifically, my data have been processed and are in a matrix with columns
>> containing the variables of interest and separate columns containing the
>> number of times this variable was observed (counts). This data frame/matrix
>> is rather large (1600 rows), and there are multiple rows corresponding to
>> the same variable level (e.g., "temperature=8, 5 observations" in one row,
>> then the next: "temperature=8, 9 observations", and so on). In other words,
>> the data are not one long vector R can read and plot as a histogram, nor are
>> they condensed. My goal is to create a figure in which one axis is bins
>> (e.g., temperature values) and the other is number of observations in this
>> bin (e.g., number of organisms seen).
>>  My question is: Is there a way R can be told to read my data to create a
>> plot like that I desire? So far I have tried several options, including bar
>> plots with no success.
>>
>>  If there is no way to do this with my data as the are currently arrange, is
>> there an efficient way to re-arrange them?
>>
>> Thanks a lot for any assistance or advice!
>>
>> Sincerely,
>> Paul Simonin
>>
>>
>> --
>> Paul W. Simonin
>> Graduate Research Assistant, MS Program
>> Vermont Cooperative Fish and Wildlife Research Unit
>> The Rubenstein School of Environment and Natural Resources
>> University of Vermont
>> 81 Carrigan Dr.
>> Burlington, VT 05405
>> Ph:802-656-3153
>>
>> ______________________________________________
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>> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>> and provide commented, minimal, self-contained, reproducible code.
>>
>
>
>
> --
> Stephen Sefick
>
> Let's not spend our time and resources thinking about things that are
> so little or so large that all they really do for us is puff us up and
> make us feel like gods.  We are mammals, and have not exhausted the
> annoying little problems of being mammals.
>
> 								-K. Mullis
>



-- 
Paul W. Simonin
Graduate Research Assistant, MS Program
Vermont Cooperative Fish and Wildlife Research Unit
The Rubenstein School of Environment and Natural Resources
University of Vermont
81 Carrigan Dr.
Burlington, VT 05405
Ph:802-656-3153