I suggest you look at the functions cut and tapply. for instance:
breaks = 0:40 / 40 bucket <- cut(purban2, breaks) used.c = tapply(used, bucket, sum) unused.c = tapply(1 - used, bucket, sum) used.c[is.na(used.c)] = 0 unused.c[is.na(unused.c)] = 0 plot(breaks[-length(breaks)], used.c / unused.c) -Alex Brown On 18 Oct 2006, at 23:24, Jeffrey Stratford wrote: > Hi. I'm trying to plot the ratio of used versus unused bird houses > (coded 1 or 0) versus a continuous environmental gradient > (proportion of > urban cover [purban2]) that I would like to convert into bins (0 - > 0.25, 0.26 - 0.5, 0.51 - 0.75, 0.76 - 1.0) and I'm not having much > luck > figuring this out. I ran a logistic regression and purban2 ends up > driving the probability of a box being occupied so it would be nice to > show this relationship. I'm also plotting the fitted values vs. > purban2 > but that's done. Any suggestions would be appreciated. > > Many thanks, > > Jeff > > > Data sample: > > box use purbank purban2 > 1 1 0.003813435 0.02684564 > 2 1 0.04429451 0.1610738 > 3 1 0.04458785 0.06040268 > 4 1 0.06072162 0.2080537 > 5 0 0.6080962 0.6979866 > 6 1 0.6060428 0.6107383 > 7 1 0.3807568 0.4362416 > 8 0 0.3649164 0.3154362 > 9 0 0.3505427 0.2483221 > 10 0 0.3476093 0.1409396 > 11 0 0.3719566 0.3020134 > 12 1 0.09238011 0.1342282 > 13 0 0.08616111 0.1073826 > 14 0 0.07388724 0.04026845 > 15 1 0.07046477 0.03355705 > . > . > . > > > **************************************** > Jeffrey A. Stratford, Ph.D. > Postdoctoral Associate > 331 Funchess Hall > Department of Biological Sciences > Auburn University > Auburn, AL 36849 > 334-329-9198 > FAX 334-844-9234 > http://www.auburn.edu/~stratja > > ______________________________________________ > [email protected] mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting- > guide.html > and provide commented, minimal, self-contained, reproducible code. ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
