Dennis, Thank you for your reply. This is a good start for what I want to achieve.
-- Joe -----Original Message----- From: Dennis Murphy [mailto:djmu...@gmail.com] Sent: Friday, May 20, 2011 10:55 PM To: Joseph Boyer Cc: r-help@r-project.org Subject: Re: [R] Variability plot in R Here's one attempt; I only used five of the wafers since you didn't provide any data. dd <- data.frame(wafer = factor(rep(1:5, each = 6)), operator = factor(rep(rep(1:3, each = 2), 5)), thickness = c(0.62, 0.66, 0.53, 0.53, 0.51, 0.55, 0.99, 1.00, 1.05, 0.93, 1.05, 1.02, 0.82, 0.81, 0.80, 0.77, 0.90, 0.77, 0.85, 0.89, 0.83, 0.76, 0.79, 0.81, 0.59, 0.48, 0.39, 0.40, 0.46, 0.51)) # Summarize the data to output the mean, sd, min and max of thickness library(ggplot2) dsumm <- ddply(dd, .(wafer, operator), summarise, tmean = mean(thickness), tmin = min(thickness), tmax = max(thickness), tsd = sd(thickness)) # 'Multi-vari' plot: p1 <- ggplot(dd) + geom_point(aes(x = wafer, y = thickness)) + geom_errorbar(data = dsumm, aes(x = wafer, y = tmean, ymin = tmin, ymax = tmax), colour = 'blue') + geom_segment(data = dsumm, aes(x = wafer, y = tmean, yend = tmean, xend = as.numeric(wafer) + 0.2), colour = 'blue') + geom_segment(data = dsumm, aes(x = wafer, y = tmean, yend = tmean, xend = as.numeric(wafer) - 0.2), colour = 'blue') + facet_wrap( ~ operator, nrow = 1) + xlab("") # Standard deviation plot p2 <- ggplot(dsumm, aes(x = wafer, y = tsd)) + geom_point(colour = 'blue') + geom_line(aes(group = 1), size = 1, colour = 'blue') + facet_wrap( ~ operator, nrow = 1) # Use the gridExtra package to combine the two graphs library(gridExtra) grid.arrange(p1, p2) HTH, Dennis On Fri, May 20, 2011 at 4:12 PM, Joseph Boyer <joseph.g.bo...@gsk.com> wrote: > Is there a package in R that can do a variability plot? > > A variability plot is a kind of categorized dot plot. (If there is a lot of > data in each category, box plots are used rather than dot plots.) > Usually, the categories are factor level combinations. All the dot plots > appear in the same window; below the x-axis a hierarchy of factors > shows which dot plot corresponds to which factor-level combination. > > Examples can be seen > http://statsoft.com/support/blog/entryid/64/user-defined-variability-plots/ > and > http://www.public.iastate.edu/~wrstephe/stat495/GaugeRR_WaferThickness_JMPOutput.pdf > > By reordering the factor names in the function call, the user can reorder the > factor level combinations on the graph, making it easier > to do the visual comparisons of interest. The user should also have the > option to draw line segments at factor level combination means/medians, and > to connect the category means/medians to make visual comparison easier. > > The only softwares which I am aware of which produce such a plot are > Statistica and JMP. I have found these plots to be more powerful than > lattice-style categorizations in their ability to allow the user to > conveniently process experimental data visually. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org 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. > ______________________________________________ R-help@r-project.org 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.
