[R] summary table newbie question

[Gabor Grothendieck]

Check out aggregate.table in package gregmisc .

Jeff D. Hamann <jeff.hamann <at> forestinformatics.com> writes:

: 
: I've got a newbie question and I got a little lost in the "table helps".
: I've got a data.frame I would like to summarize as a (and pardon for the
: lack of correct vernacular) data collection matrix. My data looks like,
: 
:    stand siteindex age      acres  pct.acres
: 1    232       116  45  8477.3105 0.56159458
: 2    234       121  25 11120.1530 0.73667441
: 3    235       132  25  5399.4605 0.35769691
: 4    236       115   5  6308.3969 0.41791103
: 5    240       116  45   473.1533 0.03134489
: 6    241       116  15 21790.9595 1.44358105
: 7    245       171  25   686.9867 0.04551066
: 8    246       134  25 15176.8082 1.00541478
: 9    247        99  35  1754.9282 0.11625835
: 10   251       125  55  7396.1098 0.48996851
: ...blah, blah, blah...
: 
: and when I attempt to create a summary table using aggregate, I get the
: following results,
: 
: > aggregate( stands$acres, by=list(stands$age,stands$siteindex), sum )
: 
:     Group.1 Group.2          x
: 1        95      86  6403.5457
: 2         5      88  1517.6781
: 3        45      88  3555.3213
: 4       125      89  6269.2633
: 5        95      90  3154.3531
: 6        55      93 14006.9781
: 7        15      94    98.9918
: 8        35      94  2241.0531
: 9       105      94   431.0281
: 
: but what I really want is a matrix where the rows and columns are classes
: (in increments of 5 or 10 or whatever) and the cells are the sums (or means
: or whatever) for the data.frame. I guess it would be equivalent to like
: surf.ls/surf.gls without fitting a trend but that would also allow me to
: plot the results graphically in addition to simply printing out the table
: using xtable.
: 
: Jeff.
: 
: ---
: Jeff D. Hamann
: Forest Informatics, Inc.
: PO Box 1421
: Corvallis, Oregon USA 97339-1421
: 541-754-1428
: jeff.hamann <at> forestinformatics.com
: www.forestinformatics.com
: 
: ______________________________________________
: R-help <at> stat.math.ethz.ch mailing list
: https://www.stat.math.ethz.ch/mailman/listinfo/r-help
: PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
: 
: