Rscript_randomize_pot_positions_on_greenhouse_tables.txt

# at start, pots are arranged in a square grid.
# each pot is assigned an ID based on its original position in the grid
# pots are given rnadom new positions, such that each pot is moved at most once; pot positions are simply swapped!
# returns a grid with the same dimensions and pots in their new positions; each grid cell has one pot id, i.e. the original position of that pot 


# specify dimensions of square grid
number_of_rows = 100
number_of_columns = 26


# construct grid
mydata <- data.frame(seq(1,number_of_rows)) 

for (i in seq(2,number_of_columns)) {
mydata <- cbind(mydata, mydata[,1])

}

colnames(mydata) <- LETTERS[1: number_of_columns]


for (i in seq(1,number_of_columns)) {
mydata[,i] <- paste(LETTERS[i], mydata[,i], sep = "")

}



##### now randomize position:

moved_already <- c()
mydata_old <- mydata
mydata_new <- mydata
for (i in sample(seq(1,number_of_columns))) {
	for (j in sample(seq(1,number_of_rows))) {
		# only move away if not already moved away
		if (!(mydata_old[j,i] %in% moved_already )) {
			# only move to where no movement yet: draw possible targets until found one that has not been moved before.
			new_col = sample(seq(1,number_of_columns), 1)
			new_row = sample(seq(1,number_of_rows), 1)
			theor_id = paste(LETTERS[new_col], new_row, sep = "")
			while (theor_id %in% moved_already) {
				new_col = sample(seq(1,number_of_columns), 1)
				new_row = sample(seq(1,number_of_rows), 1)
				theor_id = paste(LETTERS[new_col], new_row, sep = "")
			}
			mydata_new[new_row, new_col ] <- mydata_old[j,i]
			mydata_new[j, i] <- mydata_old[new_row, new_col]
			moved_already <- c(moved_already, theor_id)
			moved_already <- c(moved_already, paste(LETTERS[i], j, sep = "") )
			mydata_old <- mydata_new
			#print(mydata_new)		
		}
	}
}		
		
#####################

# is the distriibution of original columns now more or less even in the new columns?

cols_at_head <- substring( as.character(unlist(mydata_new[,c(1,2,3)])), 1, 1)
cols_at_tail <- substring( as.character(unlist(mydata_new[,c(number_of_columns-2,number_of_columns-1,number_of_columns)])), 1, 1)

cnt_head = length( cols_at_head[cols_at_head %in% c("A","B","C")] )
cnt_tail = length( cols_at_tail[cols_at_tail %in% c("A","B","C")] )

print(c(cnt_head, cnt_tail))


# export as a PDF

library(gridExtra)
pdf("pot_positions_randomized.pdf", height=11, width=10)
grid.table(mydata_new)
dev.off()