•To enter one data point with a single coordinate value, the argument for Σ+ must be a real number.

•To enter one data point with multiple coordinate values, the argument for Σ+ must be a vector with m real coordinate values.

•To enter several data points, the argument for Σ+ must be a matrix of n rows of m real

coordinate values.

In each case, the coordinate values of the data point(s) are added as new rows to the current statistics matrix (reserved variable ΣDAT). If ΣDAT does not exist, Σ+ creates an n x m matrix and stores the matrix in ΣDAT. If ΣDAT does exist, an error occurs if it does not contain a real matrix, or if the number of coordinate values in each data point entered with Σ+ does not match the number of columns in the current statistics matrix.

Once ΣDAT exists, individual data points of m coordinates can be entered as m separate real numbers or an m-element vector. LASTARG returns the m-element vector in either case.

Access: …µΣ+

Input/Output:

Lm/A1 … L2/Am–1L1/AmL1/I1

 

x

→

 

[ x1, x2, …, xm ]

→

 

[[ x1 1, …, x1 m ] [ xn 1, … ,xn m ]]

→

x1 … xm–1

xm

→

 

L = Level; A = Argument; I = Item

Example:

The sequence CLΣ [ 2 3 4 ] Σ+ 3 1 7 Σ+ creates the matrix

 

[[ 2 3 4 ][ 3 1 7 ]] in ΣDAT.

See also:

CLΣ, RCLΣ, STOΣ, Σ–

 

Σ– (Sigma Minus)

Type:

Command

Description:

Sigma Minus Command: Returns a vector of m real numbers (or one number x if m = 1)

 

corresponding to the coordinate values of the last data point entered by Σ+ into the current

 

statistics matrix (reserved variable ΣDAT).

The last row of the statistics matrix is deleted.

The vector returned by Σ– can be edited or replaced, then restored to the statistics matrix by Σ+.

Access: …µΣ–

Input/Output:

 

 

 

Level 1/Argument 1

Level 1/Item 1

 

 

 

 

 

 

 

 

→

x

 

 

 

→

[ x1 x2 … xm ]

 

CLΣ, RCLΣ,

 

 

See also:

STOΣ, Σ+

 

 

 

 

 

 

π

(Pi)

Function

 

Type:

 

 

Description: π Function: Returns the symbolic constant ' π ' or its numerical representation, 3.14159265359. The number returned for π is the closest approximation of the constant π to 12-digit accuracy. In Radians mode with flag –2 and –3 clear (to return symbolic results), trigonometric functions of

πand π/2 are automatically simplified. For example, evaluating 'SIN(π)' returns zero. However, if

3-290 Full Command and Function Reference