====== read full matrix data ======
  * file: read_tag-fullMatrix.r
  * document page: 38

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**code:**
<code>
#----open XML package-----------------------------------------------------------
library(XML)

#----read data between an XML tag-----------------------------------------------
filename = "D:/Heidi/Master/R_Daten/XML/XML_with_inserted_data.xml"
tag = "//pairwise_differences"
doc = xmlTreeParse(filename, useInternal = TRUE)
ch = getNodeSet(doc, tag)

subDoc = xmlDoc(ch[[1]])
tagData <- xpathApply(subDoc, tag, xmlValue)
free(subDoc)
#print(tagData, indent=FALSE)


#----convert string data (full matrix) to a numeric matrix----------------------
#----split string----
tagData2 <- as.character(tagData)

tagData3 <- strsplit(tagData2, "\n")
tagMatrix <- as.matrix(as.data.frame(tagData3))
tagMatrix <- gsub(" + ", " ", tagMatrix)   # trim white space

tagMatrix <- tagMatrix[12:nrow(tagMatrix)]
Data <- strsplit(tagMatrix, " ")

#----to numeric matrix----
Row <- length(Data)

Matrix <- as.matrix(as.data.frame(Data[1]))
Matrix <- Matrix[3:(nrow(Matrix))]
Matrix <- as.numeric(Matrix)
numericMatrix <- t(as.matrix(Matrix))

for(n in 2:(Row)){
  nextrow <- as.matrix(as.data.frame(Data[n]))
  nextrow <- nextrow[3:(nrow(nextrow))]
  nextrow <- as.numeric(nextrow)
  numericMatrix <- rbind(numericMatrix, t(as.matrix(nextrow)))
}

numericMatrix
</code>