Dear all,
I am searching for a possibility to view large data sets (e.g. stored in
ffdf objects) in a GUI window in a memory-efficient way. So far I looked
at gtkDfEdit (package RGtk2Extras) and gdf (package gWidgets). Both
operate (as far as I can see) on data frames stored in memory. gtkDfEdit
accepts an ff data frame as input, but there is a long delay before it
shows up, so I presume the data is converted to an in-memory data.frame
beforehand.
Ideal would be a solution similar to JTable in Java, where one can
implement a 'table model' class with a method ("getValueAt" or
sth. like
that) that returns the value of the underlying data for a given table
cell (by x and y coordinates). When the table is drawn, getValueAt() is
called for each cell in the viewable area. Cells outside the viewable
range are not queried, so there is no need to keep the whole data in
memory - it can be fetched from disk or computed on demand.
Before I seriously consider coding a suitable function or class myself,
I would like to ask you, the R community, if anyone knows of an existing
solution. To summarize, I need
- a scrollable spreadsheet-like GUI element to view and potentially
edit data
- which only loads as much of the data as it displays at one point
in time,
- thereby able to handle datasets that are too large to fit into
main memory
Thanks for any suggestions,
Andreas
--
Andreas Borg
Medizinische Informatik
UNIVERSIT?TSMEDIZIN
der Johannes Gutenberg-Universit?t
Institut f?r Medizinische Biometrie, Epidemiologie und Informatik
Obere Zahlbacher Stra?e 69, 55131 Mainz
www.imbei.uni-mainz.de
Telefon +49 (0) 6131 175062
E-Mail: borg at imbei.uni-mainz.de
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