(This article was first published on

**Quantitative Doodles**, and kindly contributed to R-bloggers)> starburst('Matrices!')

M M M a a a t t t rrr Matrices! ccc e e e s s s ! ! !

wrathematic led me FibBuzz, which led me to Starburst. Now that it’s over, you can see my solution, which uses R matrices.

v=strsplit(readLines('stdin'),'')[[1]] d=length(v) h=d/2+0.5 m=matrix(' ',d,d) diag(m)=m[h,]=m[,h]=diag(m[d:1,])=v invisible(cat((apply(m,2,paste,collapse='')),sep='\n'))

It’s rather long, but I think that’s more the input-reading and the printing rather than the arranging. Here’s the code in a more legible form.

starburst<-function(s){ letters<-strsplit(s,'')[[1]] side<-nchar(s) half<-side/2+0.5 m<-matrix(' ',side,side) diag(m)<-m[half,]<-m[,half]<-diag(m[side:1,])<-letters invisible(cat((apply(m,2,paste,collapse='')),sep='\n')) } s<-readLines('stdin') # s<-'Tommy' # if you don't want to read from stdin

And then we run it.

> starburst(s) > starburst('Voilà') V V V ooo Voilà lll à à à

It currently doesn’t work for single-letter words.

> starburst('R') Error in `diag<-`(`*tmp*`, value = "R") : only matrix diagonals can be replaced

To

**leave a comment**for the author, please follow the link and comment on his blog:**Quantitative Doodles**.R-bloggers.com offers

**daily e-mail updates**about R news and tutorials on topics such as: visualization (ggplot2, Boxplots, maps, animation), programming (RStudio, Sweave, LaTeX, SQL, Eclipse, git, hadoop, Web Scraping) statistics (regression, PCA, time series, trading) and more...