[R] duplicate data points on a line graph

[Chuck Cleland]

On 7/15/2009 9:56 PM, Carl Witthoft wrote:
> If you want to take the second  approach, it can be relatively easily
> generalized by calculating the cex values based on the count of ordered
> pairs in the original dataset.
> 
> Here's a data set:
>> xy
>      x y
> [1,] 1 4
> [2,] 1 5
> [3,] 2 3
> [4,] 3 3
> [5,] 4 5
> [6,] 5 2
> [7,] 1 4
> [8,] 2 3
> 
> Here's the same set fully sorted:
> 
> xy[order(x,y),]->xyord
>      x y
> [1,] 1 4
> [2,] 1 4
> [3,] 1 5
> [4,] 2 3
> [5,] 2 3
> [6,] 3 3
> [7,] 4 5
> [8,] 5 2
> 
> There's gotta be some very simple way to create a series of values for
> cex but I'm missing it, other than a loop like
> 
> cexvec<-rep(1,8)
> for i in 2:8 {
> if (xyord[i,1]==xyord[i-1,1] & xyord[i,2]== xyord[i-1,2] ) {
> 
> cexvec[i]<-cexvec[i-1]+1
> }
> }

  How about using ave() like this:

x <- sample(0:4, 60, replace=TRUE)
y <- sample(0:4, 60, replace=TRUE)
xy <- data.frame(x, y)
xy$freq <- ave(xy$x, x, y, FUN=length)

with(xy, plot(x, y, cex=freq))

> You get the idea, sort of  :-)
> 
> Carl
> 
> 
> On 7/15/2009 2:19 PM, NDC/jshipman wrote:
>> Hi,
>>     I am new to R plot.  I am trying to increase the data point
>> observation when duplicate data points exist
>>
>> x    y
>> 1    10
>> 1    10
>> 2    3
>> 4    5
>> 9     8
>>
>>
>> in the about example  1, 10 would be displayed larger than the other
>> data points.  Could someone give me some assistance with this problem
> 
>   A couple of simple approaches:
> 
> x <- c(1,1,2,4,9)
> 
> y <- c(10,10,3,5,8)
> 
> plot(jitter(x), jitter(y))
> 
> plot(x, y, cex=c(2,2,1,1,1))
> 
>> 757-864-7114
>> LARC/J.L.Shipman/jshipman
>> Jeffery.L.Shipman at nasa.gov
> 
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-- 
Chuck Cleland, Ph.D.
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