Blog Archives

Simulation of Burning Fire in R

June 11, 2009
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Simulation of Burning Fire in R

inlin Yan posted a cool (hot?) simulation of burning fire with R in the COS forum yesterday, which was indeed a warm welcome. I’m not sure whether our forum members will be scared by the “fire” under the title “Welcome to COS Forum”. The fire was mainly created by the function image() with

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Creating Tag Cloud Using R and Flash / JavaScript (SWFObject)

June 10, 2009
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Creating Tag Cloud Using R and Flash / JavaScript (SWFObject)

ag cloud is a bunch of words drawn in a graph with their sizes proportional to their frequency; it’s widely used in blogs to visualize tags. We can observe important words quickly from a tag cloud, as they often appear in large fontsize. Tony N. Brown asked how to “graphically represent frequency of words in

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Enhanced tidy.source() (Preserve Some Comments)

March 31, 2009
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After a few hours’ work, I modified the function tidy.source() in the animation package so that it can preserve complete comment lines. See the tidy.source() wiki page for example. tidy.source <- function(source = "clipboard", keep.comment = TRUE, keep.blank.line = FALSE, begin.comment, end.comment, ...) { # parse and deparse the code tidy.block = function(block.text)

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Identify Data Points in Off-Screen R Graphics Devices

March 16, 2009
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Today Ruya Gokhan Kocer asked me how to use the R function identify() in off-screen graphics devices. Actually it’s pretty easy as long as we obtain the list returned by identify(pos = TRUE). For example, # open a windows device x11() x = rnorm(20) y = rnorm(20) plot(x, y) # identify 5 points id = identify(x, y, n = 5, pos =

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