Below are various attempts using using ggplot2 (http://had.co.nz/ggplot2/). First I try random positioning, then random positioning with alpha, then a quasi-random position scheme in polar coordinates:
#this demo has random number generation # so best to set a seed to make it # reproducible. set.seed(1) #generate some fake data a = data.frame( word = month.name , freq = sample(1:10,12,replace=TRUE) ) #add arbitrary location information a$x = sample(1:12,12) a$y = sample(1:12,12) #load ggplot2 library(ggplot2) #initialize a ggplot object my_plot = ggplot() #create an object for the text layer my_text = geom_text( data = a , aes( x = x , y = y , label = word , size = freq ) ) #create an object for the text size limits my_size_scale = scale_size( to = c(3,20) ) #create an object to expand the x-axis limits # (ensures that text isn't cropped) my_x_scale = scale_x_continuous( expand = c(.5, 0) ) #ditto for the y axis my_y_scale = scale_y_continuous( expand = c(.5, 0) ) #create an opts object that removes # plot elements unnecessary in a tag cloud my_opts = opts( legend.position = 'none' , panel.grid.minor = theme_blank() , panel.grid.major = theme_blank() , panel.background = theme_blank() , axis.line = theme_blank() , axis.text.x = theme_blank() , axis.text.y = theme_blank() , axis.ticks = theme_blank() , axis.title.x = theme_blank() , axis.title.y = theme_blank() ) #show the plot print( my_plot+ my_text+ my_size_scale+ my_x_scale+ my_y_scale+ my_opts ) #to aid readability amidst overlap, set alpha in # the call to geom_text my_text_with_alpha = geom_text( data = a , aes( x = x , y = y , label = word , size = freq ) , alpha = .5 ) #show the version with alpha print( my_plot+ my_text_with_alpha+ my_size_scale+ my_x_scale+ my_y_scale+ my_opts ) #alternatively, in polar coordinates, # which maps x to angle and y to radius, # making a nice circle print( my_plot+ my_text_with_alpha+ my_size_scale+ my_opts+ coord_polar() ) #(note omission of my_y_scale & # my_x_scale, which seem to be ignored # when coord_polar() is called. I'll # report this possible bug to the ggplot2 # maintainer) #a possible way to avoid overlap is to # map radius (y) to frequency so that # larger text is in the periphery # where there is more room. This # necessitates adding some random # noise to the frequency so that # the low frequency words don't # jumble in the center too badly a$freq2 = a$freq+rnorm(12) #now map radius (y) to freq2 my_text_with_alpha_and_freq2 = geom_text( data = a , aes( x = x , y = freq2 , label = word , size = freq ) , alpha = .5 ) #show the version with alpha & radius mapped to freq2 print( my_plot+ my_text_with_alpha_and_freq2+ my_size_scale+ my_opts+ coord_polar() ) -- Mike Lawrence Graduate Student Department of Psychology Dalhousie University Looking to arrange a meeting? Check my public calendar: http://tr.im/mikes_public_calendar ~ Certainty is folly... I think. ~ ______________________________________________ Rfirstname.lastname@example.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.