Opasnet Base Connection for R

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Revision as of 12:27, 20 August 2010 by Teemu R (talk | contribs)
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Code for R for the purpose of interacting with the Opasnet Base is collected on this page. To use it, copy paste the code to R; this defines the functions, after which they can be called in R. I've tried to explain the code in comments (#). This is a work in progress, if you have comments or new ideas post them using the comment templates on a new line after the one you want to comment, I'm no expert in programming so input is appreciated :P.

Package dependencies

These packages are required for most of the code to work. Load these first.

  1. utils
  2. RODBC

Setup

Establishes the connection to the database. Copy paste first. 

db <- odbcConnect("opasnet_base") #assuming "opasnet_base" is the defined DSN

Downloading data

At the moment very sensitive to glitches in the database (multiple locations for the same index for a single cell), and does not handle large quantities of data well. Ideally should work, testing needed... The only page that I came across that does not give errors is Population of Europe, though probably because of the size of the data only the first hundred or so cells become populated, incorrectly... A lot of cells in data on many pages seem to be missing location data altogether... The code seems to break up in a different way every time I copy paste it to a new instance of R...

Low level functions (mainly sql queries)

Copy paste these second. 

#Get latest series id
op_baseGetLatest <- function(ident) {
	series_list <- sqlQuery(db, paste('
		SELECT actobj.series_id 
		FROM obj 
		LEFT JOIN actobj 
		ON obj.id = actobj.obj_id ',
		'WHERE obj.ident = "', ident, '"', sep = ))
	series_list[nrow(series_list),1]
}

#Get results (cell id, result)
op_baseGetData <- function(series_id) {
	sqlQuery(db, paste('
		SELECT cell.id, res.result 
		FROM actobj 
		LEFT JOIN cell 
		ON actobj.id = cell.actobj_id 
		LEFT JOIN res 
		ON cell.id = res.cell_id 
		WHERE actobj.series_id = ', series_id, sep = ))
}

#Not in use: Get indexes and locations per cell
op_baseGetDims <- function(cell_id_list) {
	sqlQuery(db, paste('
		SELECT loccell.cell_id, loc.id, loc.location, loc.obj_id_i, obj.name 
		FROM loccell 
		LEFT JOIN loc 
		ON loccell.loc_id = loc.id 
		LEFT JOIN obj 
		ON loc.obj_id_i = obj.id 
		WHERE loccell.cell_id BETWEEN ', cell_id_list[1,1], ' AND ', cell_id_list[nrow(cell_id_list),1], sep = ))
}

#Experimental: Sort locations by index
#tapply(dims_table[,3], dims_table[,5], paste)

#Not in use: Get indexes from dims_table
op_baseFindInd <- function(dims_table) {
	factor(op_baseDims[,4]) #could also use "obj_id_i"(obj.name for index) instead of 5 for column name
}

#Get indexes
op_baseGetInd <- function (cell_id_list) {
	indexes <- sqlQuery(db, paste('
		SELECT DISTINCT loc.obj_id_i 
		FROM loccell 
		LEFT JOIN loc 
		ON loccell.loc_id = loc.id 
		WHERE loccell.cell_id 
		BETWEEN ', cell_id_list[1,1], ' AND ', cell_id_list[nrow(cell_id_list),1], sep = ))
	as.numeric(indexes[,1])
}

#Get locations
op_baseGetLoc <- function(index, cell_id_list) {
	locations <- sqlQuery(db, paste('
		SELECT DISTINCT loc.id 
		FROM loccell 
		LEFT JOIN loc 
		ON loccell.loc_id = loc.id 
		WHERE loc.obj_id_i = ', index, ' AND loccell.cell_id BETWEEN ', cell_id_list[1,1], ' AND ', cell_id_list[nrow(cell_id_list),1], sep = ))
	as.numeric(locations[,1])
}

#Get location names (will not work properly if different indexes have locations with similar name)
op_baseGetLocNames <- function(index, cell_id_list) {
	locations <- sqlQuery(db, paste('
		SELECT DISTINCT loc.location 
		FROM loccell 
		LEFT JOIN loc 
		ON loccell.loc_id = loc.id 
		WHERE loc.obj_id_i = ', index, ' AND loccell.cell_id BETWEEN ', cell_id_list[1,1], ' AND ', cell_id_list[nrow(cell_id_list),1], sep = ))
	as.numeric(locations[,1])
}

#Get location name (simple)
op_baseGetLocName <- function(loc_id) {
	sqlQuery(db, paste('
		SELECT location 
		FROM loc 
		WHERE id = ', loc_id, sep = ))
}

#Get index name
op_baseGetIndName <- function(ind_id) {
	sqlQuery(db, paste('
		SELECT name 
		FROM obj 
		WHERE id = ', ind_id, sep = )) }

#Get locations for a specific cell
op_baseGetLocs <- function(cell_id) {
	sqlQuery(db, paste('
		SELECT DISTINCT loc.location, loc.id 
		FROM loccell 
		LEFT JOIN loc 
		ON loccell.loc_id = loc.id 
		WHERE loccell.cell_id = ', cell_id, sep = )) #backup: 'AND loc.obj_id_i BETWEEN ', <<<INDEX>>>, ' AND ', <<<INDEX>>>
}

High Level function

Copy paste this last. 

op_baseArray <- function(page_ident) {
	
	#Basic data downloading
	
	op_baseLatest <- op_baseGetLatest(page_ident)
	op_baseData <- op_baseGetData(op_baseLatest) #cell,result
	#final_array <- op_baseData[,2] #ideal case (data in proper order)
	#op_baseDims <- op_baseGetDims(op_baseData)
	#op_baseIndexes <- op_baseFindInd(op_baseDims)
	op_baseInd <- op_baseGetInd(op_baseData)
	
	#Array structure building
	
	IndLengths <- 1:3 #blank vector for index lengths
	IndList <- rep(vector("list", 1), length(op_baseInd)) #blank list of appropriate length for indexes and 
	#locations for naming the dimensions of the array
	IndIdList <- rep(vector("list", 1), length(op_baseInd)) #blank list of appropriate length for ids of indexes
	IndNames <- c(1) #blank vector for index names
	#temp <- c(1) #temporary vector
	for (i in 1:length(op_baseInd)) {
		IndIdList[[i]] <- op_baseGetLoc(op_baseInd[i], op_baseData) #fetch location ids in index to a list, 
 		#assumed every cell has locations for all unique index id values in loc.obj_id_i in the range of cells
		IndNames[i] <- paste(op_baseGetIndName(op_baseInd[i])[1,1]) #fetch index name to a vector
		IndLengths[i] <- length(IndIdList[[i]]) #backup: op_baseGetLoc(op_baseInd[i], op_baseData))
		for (j in 1:IndLengths[i]) { 
			#temp[[i]][j] <- op_baseGetLocName(IndIdList[[i]][j])
			IndList[[i]][j] <- paste(op_baseGetLocName(IndIdList[[i]][j])[1,1])
		}
		#IndList[[i]] <- temp[[i]]
	}
	final_array <- rep(NA, prod(IndLengths))
	dim(final_array) <- IndLengths
	names(IndList) <- IndNames
	dimnames(final_array) <- IndList
	
	#Cell population
	
	LocList <- c(1) #blank vector for locations per cell
	LocMap <- c(1) #blank vector for location to position mapping
	CellPosition <- c(1) #blank vector for cell position
	for (i in 1:length(op_baseData[,1])) { #for each cell
		LocList <- paste(op_baseGetLocs(op_baseData[i,1])[,1]) #get list of locations
		for (j in 1:length(LocList)) { #for each location per cell
			LocMap <- 1:IndLengths[j] #get available positions in given index, assumed correct order of indexes in LocList
			names(LocMap) <- dimnames(final_array)[[j]] #add names (locations) of positions in given index
			CellPosition[j] <- LocMap[LocList[j]] #match cell specific locations to positions in index
		}
		final_array[CellPosition] <- op_baseData[i,2] #insert result in array in position determined by CellPosition
	}
	final_array #print/return the final array
}

Usage

variable <- op_baseArray("<page identifier>")
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