exports to the csv format, without labels, a matrix or the .d field within a Div structure
div2dcsv(x_div,'mycsvdata',(field), (decimal)));
a matrix (n x q) or a Div structure
the name of the csv file; a string
the field separator; a comma ',' (by default) or a semi-column ';'
the decimal separator; a dot '.' (by default) or a comma ','