Texas Instruments TI-89 Titanium - Page 522

Data/Matrix Editor 519
Note: To enter shift, type it from the keyboard or select it from the CATALOG.
Using the CumSum Function
The
cumSum function returns a cumulative sum of the elements in a base column. Use
† to define a column header with the syntax:
For example:
Note: To enter cumSum, type it, select it from the CATALOG, or press 2 I and
select it from the List submenu.
ÊË
Ì
Í Î
Ê c2=shift(c1,2)
Ë c3=shift(c1,M2)
Ì Shifted columns have the same length as the base
Í Last two elements of c1 shift down and out the
bottom; undefined elements shift into the top.
Î First two elements of c1 shift up and out the top;
undefined elements shift into the bottom.
cumSum (column)
Column used as the base for the cumulative sum.
1+2
1+2+3+4
c2=cumSum(c1)