[R] "spreading out" a numeric vector

[jim holtman]

Is this close to what you want?

> spread <- function(x, mindiff=0.5){
+     unique(as.integer(x / mindiff) * mindiff)
+ }
>
> x <- c(1,2,seq(2.1,2.3,0.1),3,4)
> x
[1] 1.0 2.0 2.1 2.2 2.3 3.0 4.0
> spread(x)
[1] 1 2 3 4
>
> spread(x,.2)
[1] 1.0 2.0 2.2 3.0 4.0
>


On Sat, Mar 22, 2008 at 8:03 PM, Levi Waldron <leviwaldron at gmail.com> wrote:
> I am creating a timeline plot, but running into a problem in positions
> where the values to plot are too close together to print the text
> without overlap.  The simplest way I can think of to solve this
> (although there may be other ways?) is to create a new numeric vector
> whose values are as close as possible to the original vector, but
> spread out to a given minimum difference.  For example, take the
> following vector:
>
> > x <- c(1,2,seq(2.1,2.3,0.1),3,4)
> > x
> [1] 1.0 2.0 2.1 2.2 2.3 3.0 4.0
> >
>
> However, suppose I don't want to plot any of these points with less
> than 0.5 between them.  The problem could be solved by a function that
> behaved something like this:
>
> > x2 <- spread(x,mindiff=0.5)
> > x2
> [1] 0.5 1.0 1.5 2.0 2.5 3.0 4.0
>
> Or for a minimum difference of 0.2,
> > x2 <- spread(x,mindiff=0.2)
> > x2
> [1] 1.0 1.8 2.0 2.2 2.4 3.0 4.0
>
> Thus, if there is a cluster of close values, spreading the values may
> require changing values which previously weren't too close to their
> nearest neighbors.
>
> Then I could use segments() to draw lines from the timeline to where
> the shifted text is printed, labeling tics on the timeline accurately
> but keeping the text from overlapping.
>
> Any ideas on how to program this or how to do it using built-in
> functions would be greatly appreciated.
>
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>



-- 
Jim Holtman
Cincinnati, OH
+1 513 646 9390

What is the problem you are trying to solve?