Model Thinking- Aggregation- Game of Life- Experiments in R

GameofLife.R

# define a set of functions for iterating through the Game of Life, as described (err, as I understood it) by Scott Page in the 2012 Model Thinking course:

# queenNeighbors() 
# given the status of the cell located and index 'ind'
# in matrix 'M' with 'n' columns, what are the statuses 
# of its neighbors 
# *neighborhoods to NOT wrap left and right but they DO wrap up and down...
queenNeighbors <- function(ind,M,n){
	inds <- ind+outer(c(-1,0,1),c(-n,0,n),"+")
	M[inds[inds > 0 & inds <= length(M) & inds != ind]]
}

# onOff() 
# given the status of the cell located and index 'ind'
# in matrix 'M' with 'n' columns, does it live or die?
onOff <- function(ind,M,n){
	status <- M[ind]
	Ons <- sum(queenNeighbors(ind,M,n))
	ifelse(status,ifelse(status & (Ons == 2 | Ons == 3),1,0),ifelse(Ons == 3,1,0))
}

# gameOfLifeCycle() 
# given a matrix M with n columns (n given as a parameter to remove call to ncol())
# what will be the ending state (starting state of next iteration)?
gameOfLifeCycle <- function(M,n){
	matrix(sapply(1:length(M),onOff,M=M,n=n),ncol=n)
}

# gameOfLife() 
# takes a starting matrix, M0 and iterates N times
gameOfLife <- function(M0,N=100){
	n <- ncol(M0)
	Mi <- M0
	MiArray <- array(dim=c(dim(M0),N+1))
	MiArray[,,1] <- M0
	for (i in 1:N){
		MiArray[,,i+1] <- gameOfLifeCycle(MiArray[,,i],n=n)
	}
	return(MiArray)
}

# an experiment. Setting the random number seed makes it so that the same
# results will be produced. remove that line to make a different experiment 
# each time
set.seed(1)
# 'GOLresults' is a 3 dimensional array 
GOLresults <- gameOfLife(matrix(sample(c(1,0),100,replace=T),ncol=10))

# iterate through as image()s and save as multipage pdf:
pdf("GameofLife.pdf")
for (i in 1:101){
	image(t(GOLresults[,,i]),axes=FALSE,main=i-1)
}
dev.off() # save and close device.

cat("GameofLife.pdf is located here:",getwd())

Hi Timriffe,

First of all thanks a lot for those R things. I learned how to use R in to years ago in my statistic class. Now, I changed my notebook, and today I install new R program. So, I try to do run my R program, but I cannot get in my data to in R. Do you know any idea how can I extract my data or why I cannot do it. If you have some suggestion, I would be very appreciated.

Thank you and good luc for model thinking class :)

to be able to help very well, I'd need to know what code you've tried, and the characteristics of the data (e.g. comma separated, etc). As far as I recall, none of the code that I've posed here requires reading in data, so I guess your question isn't related to Model Thinking. Consider reading a beginner's tutorial, such as this one: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=5&ved=0CEwQFjAE&url=http%3A%2F%2Fwww.springer.com%2Fcda%2Fcontent%2Fdocument%2Fcda_downloaddocument%2F9780387938363-c2.pdf%3FSGWID%3D0-0-45-772114-p173894303&ei=IFx7T_W3E9PqggfNsOWBAw&usg=AFQjCNF4Sc602efZTzF1ESAHAG7KQF7hcA&sig2=kBsLZbKd3LaawTc7QvAs1Q