# Cov; Crdir; Cross - HP 48gII Advanced User's Reference Manual

Graphing calculator.

## COV

Type:
Command
Description: Covariance Command: Returns the sample covariance of the independent and dependent data
columns in the current statistics matrix (reserved variable DAT).
The columns are specified by the first two elements in reserved variable PAR, set by XCOL
and YCOL respectively. If PAR does not exist, COV creates it and sets the elements to their
default values (1 and 2).
The covariance is calculated with the following formula:
where
x
in
1
n
,
is the mean of the data in column n
x
2
n
1
the number of data points.
...µ
Access:
Input/Output:
COL , CORR, PCOV, PREDX, PREDY, XCOL, YCOL
CR
Type:
Command
Description: Carriage Right Command: Prints the contents, if any, of the printer buffer.
CR sends to the printer a string that encodes the line termination method. The default
termination method is carriage-return/linefeed. The string is the fourth parameter in the reserved
variable PRTPAR.
...µ
Access:
Flags:
I/O Device (–33), Printing Device (–34), Double-Spaced Printing (–37)
Input/Output: None
DELAY, OLDPRT, PRLCD, PRST, PRSTC, PRVAR, PR1

### CRDIR

Type:
Command
Description: Create Directory Command: Creates an empty subdirectory with the specified name in the
current directory.
CRDIR does not change the current directory; evaluate the name of the new subdirectory to
make it the current directory.
Access:
Input/Output:
HOME, PATH, PGDIR, UPDIR

### CROSS

Type:
Command
Description: Cross Product Command: CROSS returns the cross product C = A × B of vectors A and B.
The arguments must be vectors having two or three elements, and need not have the same
number of elements. (The hp49g+/hp48gII automatically converts a two-element argument
----------- -
n 1
is the ith coordinate value in column n
COV
Level 1/Argument 1
CR
MEMORY DIRECTORY CRDIR
Level 1/Argument 1
'global'
n
1
x
x
x
x
in
n
in
1
1
2
i
=
1
,
is the ith coordinate value in the column
x
1
in
2
,
is the mean of the data in column n
x
1
n
2
( °is the left-shift of the Nkey).
Full Command and Function Reference 3-37
n
2
Level 1/Item 1
x
covariance
Level 1/Item 1
, and n is
2