Texas Instruments TI-89 Titanium - Page 263

Appendix A: Functions and Instructions 257
Unarchiv CATALOG
Unarchiv var1 [, var2 ] [, var3 ] …
Moves the specified variables from the user data
archive memory to RAM.
You can access an archived variable the same as
you would a variable in RAM. However, you
cannot delete, rename, or store to an archived
variable because it is locked automatically.
To archive variables, use
Archive.
10!arctest ¸ 10
Archive arctest ¸ Done
5ù arctest ¸ 50
15!arctest ¸
N
Unarchiv arctest ¸ Done
15!arctest ¸ 15
unitV() MATH/Matrix/Vector ops menu
unitV( vector1 ) ⇒ vector
Returns either a row- or column-unit vector,
depending on the form of
vector1 .
vector1 must be either a single-row matrix or a
single-column matrix.
unitV([a,b,c]) ¸
[
a
añ +bñ +cñ
b
añ +bñ +cñ
c
añ +bñ +cñ
]
unitV([1,2,1]) ¸
[
‡6
6
‡6
3
‡6
6
]
unitV([1;2;3]) ¸








‡14
14
‡14
7
3ø ‡14
14
Unlock CATALOG
Unlock var1 [, var2 ][ , var3 ]...
Unlocks the specified variables.
Note: The variables can be locked using the
Lock command.
variance() MATH/Statistics menu
variance( list [ , freqlist ]) ⇒ expression
Returns the variance of list .
Each
freqlist element counts the number of
consecutive occurrences of the corresponding
element in
list .
Note:
list must contain at least two elements.
variance({a,b,c}) ¸
añ -aø (b+c)+bñ -bø c+cñ
3
variance({1,2,5,ë 6,3,ë 2}) ¸
31/2
variance({1,3,5},{4,6,2}) ¸
68/33
variance( matrix1 [ , freqmatrix ]) ⇒ matrix
Returns a row vector containing the variance of
each column in
matrix1 .
Each
freqmatrix element counts the number of
consecutive occurrences of the corresponding
element in
matrix1 .
Note:
matrix1 must contain at least two rows.
variance([1,2,5;ë 3,0,1;
.5,.7,3])
¸ [4.75 1.03 4]
variance([L1.1,2.2;3.4,5.1;
L2.3,4.3],[6,3;2,4;5,1]) ¸
[3.91731,2.08411]