Parse string of comparisons into a matrix

This function parses a string of pairwise comparisons into a matrix of graph.
The output matrix is a graph representing the input string of pairwise comparisons.
Example:
The input 'str' is a string containing descriptions of multiple comparisons, separated by 'delimiter'.
str = 'a > b ; c < b ; a > c < b' ; delimiter = ';'; ifSortElement = 1;
[out, elements] = PairwiseCompareString2GraphMatrix(str, delimiter, ifSortElement)
>> out =
0 1 1
0 0 1
0 0 0
, where the output matrix 'out' is a matrix of the truth values for each comparison, such that :
[a>a] [a>b] [a>c]
[b>a] [b>b] [b>c]
[c>a] [c>b] [c>c]
>> elements =
'a' 'b' 'c'
The output 'elements' contains the unique elements
in the input string, corresponding to
the row and column indice of the output matrix 'out'. .
If ' ifSortElement' = 1, then the output elements will be sorted.
If ' ifSortElement' = 0, then the output elements will be ordered as they appear in the input string.