I'm not clear that that function will work. Right now my data are analogous to:
Task 1 arm; Task 1 leg; Task 2 arm; Task 2 leg; Task 3 arm; Task 3 leg; Task 3 face
Except that the variable names diverge from the format above and aren't all consistent. I want to stack the Task 1 values, and also separately the Task 2 values, and also separately the Task 3 values, but all joined by the Body Site variable:
Arm Task 1 value Task 2 value. (no data)
Leg Task 1 value Task 2 value. (no data)
Face Task 1 value Task 2 value Task 3 value