Try this:

plot(January[January[,3] > 0, 3:4])

On Thu, Sep 4, 2008 at 1:28 PM, Steve Murray <smurray444@hotmail.com> wrote:

>
>
> Dear all,
>
> I have a dataset of four columns, and I wish to plot (as a scatter graph)
> the values of the third column where the values are greater than zero, and
> the fourth column.
>
> I tried doing this via the plot command itself, but got into a bit of a
> mess (resulting in errors!). My dataframe is called 'January':
>
> > plot(January[3(>0):4])
> Error: unexpected '>' in "plot(January[3(>"
>
>
> After a few variations on this, I thought I'd try making a new object which
> includes all values from the third column of January>0 (to plot in a
> separate step) as follows:
>
> > JanFilter <- January[3]>0
>
> No error here. However, when I display the 'values' of JanFilter, it shows
> that instead of keeping the numerical values, the above operation simply
> displays the results of the logical test:
>
> > head(JanFilter)
>                             Value
> [1,]                       FALSE
> [2,]                        TRUE
> [3,]                        TRUE
> [4,]                        TRUE
> [5,]                        TRUE
> [6,]                        TRUE
>
>
> This is obviously no good for plotting the numerical values on axes!
>
> So my question is, how do I perform 'if' statements in order to filter out
> various parts of a dataset, for plotting on a graph.
>
> Many thanks,
>
> Steve
>
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>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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