Pierz,
- easy approximation: use coulours with alpha value for plotting points
> x <- runif (1000)
> y <- runif (1000) * x + x
> plot (x, y)
> plot (x, y, pch = 20, col = "#FF000020")
- more sophisticated:
have a look at hexbin (package hexbin), levelplot (package lattice), package
ggplot2 with stat_sum, stat_binhex, or stat_density2d (e.g.
http://had.co.nz/ggplot2/stat_sum.html)
HTH Claudia
On 02/28/2011 03:21 PM, pierz wrote:
Let me start by introducing myself as a biologist with only a little
knowledge about programming in matlab and R. In the past I have succesfully
created my figures in matlab using the hist3d command, but I have not access
to matlab right now and would like to switch to R.
I have used the plot command to create a figure of my data and it does
almost what I want it to do.
My data matrix looks like this (these are the first few lines from it,
copied from R console):
Time Abs
[1,] 0.09714286 24
[2,] 0.19428571 24
[3,] 0.19428571 24
[4,] 0.29142857 24
[5,] 0.38857143 23
[6,] 0.38857143 22
[7,] 0.48571429 23
[8,] 0.58285714 21
[9,] 0.58285714 21
[10,] 0.68000000 23
[11,] 0.68000000 25
[12,] 0.68000000 23
[13,] 0.77714286 23
[14,] 0.77714286 23
[15,] 0.87428571 21
[16,] 0.87428571 20
[17,] 0.87428571 22
[18,] 1.06857143 23
[19,] 1.06857143 25
The example shows that some of the plotted points appear more than once. I
would like to use a heatmap to show that these points have more weight, but
I have difficulty arranging the data to be plotted correctly using the
image() or heatmap() command.
So what I would want to do is to get the same figure as when I use the plot
command, but have colors representing the weight of the plotted points
(wether they occur once, twice or multiple times).
I have tried searching this forum and also used google, but I seem to keep
going in circles. I think that the image() command fits my needs, but that
my input data is not in the correct format.
Attached I have an image example from R and an image example from matlab.
This is how far I got using R:
http://r.789695.n4.nabble.com/file/n3327986/example_R.jpg
This is the result I am aiming for:
http://r.789695.n4.nabble.com/file/n3327986/example_matlab.jpg
--
Claudia Beleites
Dipartimento dei Materiali e delle Risorse Naturali
Università degli Studi di Trieste
Via Alfonso Valerio 6/a
I-34127 Trieste
phone: +39 0 40 5 58-37 68
email: cbelei...@units.it
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