[R] Speed up plotting to MSWindows graphics window

[jim holtman]

If you are plotting that many data points, you  might want to look at
'hexbin' as a way of aggregating the values to a different
presentation.  It is especially nice if you are doing a scatter plot
with a lot of data points and trying to make sense out of it.

On Wed, Apr 27, 2011 at 5:16 AM, Jonathan Gabris <jonathan at k-m-p.nl> wrote:
> Hello,
>
> I am working on a project analysing the performance of motor-vehicles
> through messages logged over a CAN bus.
>
> I am using R 2.12 on Windows XP and 7
>
> I am currently plotting the data in R, overlaying 5 or more plots of data,
> logged at 1kHz, (using plot.ts() and par(new = TRUE)).
> The aim is to be able to pan, zoom in and out and get values from the
> plotted graph using a custom Qt interface that is used as a front end to
> R.exe (all this works).
> The plot is drawn by R directly to the windows graphic device.
>
> The data is imported from a .csv file (typically around 100MB) to a matrix.
> (timestamp, message ID, byte0, byte1, ..., byte7)
> I then separate this matrix into several by message ID (dimensions are in
> the order of 8cols, 10^6 rows)
>
> The panning is done by redrawing the plots, shifted by a small amount. So as
> to view a window of data from a second to a minute long that can travel the
> length of the logged data.
>
> My problem is that, the redrawing of the plots whilst panning is too slow
> when dealing with this much data.
> i.e.: I can see the last graphs being drawn to the screen in the half-second
> following the view change.
> I need a fluid change from one view to the next.
>
> My question is this:
> Are there ways to speed up the plotting on the MSWindows display?
> By reducing plotted point densities to *sensible* values?
> Using something other than plot.ts() - is the lattice package faster?
> I don't need publication quality plots, they can be rougher...
>
> I have tried:
> -Using matrices instead of dataframes - (works for calculations but not
> enough for plots)
> -increasing the max usable memory (max-mem-size) - (no change)
> -increasing the size of the pointer protection stack (max-ppsize) - (no
> change)
> -deleting the unnecessary leftover matrices - (no change)
> -I can't use lines() instead of plot() because of the very  different scales
> (rpm-10000, flags -1to3)
>
> I am going to do some resampling of the logged data to reduce the vector
> sizes.
> (removal of *less* important data and use of window.ts())
>
> But I am currently running out of ideas...
> So if sombody could point out something, I would be greatfull.
>
> Thanks,
>
> Jonathan Gabris
>
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>



-- 
Jim Holtman
Data Munger Guru

What is the problem that you are trying to solve?