Return a symbolic object with the following internal format:
$M
[1] 5
$var.types
[1] '$C' '$H' '$I' '$H' '$C'
$var.length
[1] 1 5 2 3 1
$var.names
[1] 'F1' 'F2' 'F3' 'F4' 'F5'
$obj.data.vector
F1 M1 M2 M3 M4 M5 F3 F3.1 M1.1 M2.1 M3.1 F5
Case4 -2.1 0.4 0.1 0.1 0.1 0.3 0 2 0.9 0 0.1 0