Texas Instruments TI-89 Titanium - Page 255

Appendix A: Functions and Instructions 249
subMat() CATALOG
subMat( matrix1 [, startRow ] [, startCol ] [, endRow ]
[, endCol ]) ⇒ matrix
Returns the specified submatrix of matrix1 .
Defaults:
startRow =1, startCol =1, endRow =last
row,
endCol =last column.
[1,2,3;4,5,6;7,8,9]! m1 ¸






1 2 3
4 5 6
7 8 9
subMat(m1,2,1,3,2)
¸
[
4 5
7 8
]
subMat(m1,2,2) ¸
[
5 6
8 9
]
Sum (Sigma) See G(), page 273.
sum() MATH/List menu
sum( list [ , start [ , end ]]) ⇒ expression
Returns the sum of the elements in list .
Start and end are optional. They specify a range of
elements.
sum({1,2,3,4,5}) ¸ 15
sum({a,2a,3a}) ¸ 6ø a
sum(seq(n,n,1,10)) ¸ 55
sum({1,3,5,7,9},3) ¸ 21
sum( matrix1 [ , start [ , end ]]) ⇒ matrix
Returns a row vector containing the sums of the
elements in the columns in
matrix1 .
Start and end are optional. They specify a range of
rows.
sum([1,2,3;4,5,6]) ¸[5 7 9]
sum([1,2,3;4,5,6;7,8,9])
¸
[12 15 18]
sum([1,2,3;4,5,6;7,8,9],2,3)
¸
[11,13,15]
switch() CATALOG
switch([ integer1 ]) ⇒ integer
Returns the number of the active window. Also
can set the active window.
Note:
Window 1 is left or top; Window 2 is right
or bottom.
If
integer1 = 0, returns the active window number.
If
integer1 = 1, activates window 1 and returns
the previously active window number.
If
integer1 = 2, activates window 2 and returns
the previously active window number.
If
integer1 is omitted, switches windows and
returns the previously active window number.
integer1 is ignored if the
TI-89 Titanium/Voyage™ 200 is not displaying a
split screen.
switch() ¸