# Function - HP 48gII Advanced User's Reference Manual

Graphing calculator.

CF, FC?, FC?C, FS?, SF

## FUNCTION

Type:
Command
Description: Function Plot Type Command: Sets the plot type to FUNCTION.
When the plot type is FUNCTION, the DRAW command plots the current equation as a real-
valued function of one real variable. The current equation is specified in the reserved variable
EQ. The plotting parameters are specified in the reserved variable PPAR, which has the form:
For plot type FUNCTION, the elements of PPAR are used as follows:
• (x
, y
min
of the display range). The default value is (–6.5,–3.1) for the hp48gII and (–6.5,–3.9) for the
hp49g+.
• (x
, y
max
corner of the display range). The default value is (6.5,3.2) for the hp48gII and (6.5,4.0) for the
hp49g+.
• indep is a name specifying the independent variable, or a list containing such a name and two
numbers specifying the minimum and maximum values for the independent variable (the
plotting range). The default value of indep is X.
• res is a real number specifying the interval (in user-unit coordinates) between plotted values of
the independent variable, or a binary integer specifying the interval in pixels. The default value
is 0, which specifies an interval of 1 pixel.
• axes is a list containing one or more of the following, in the order listed: a complex number
specifying the user-unit coordinates of the plot origin, a list specifying the tick-mark
annotation, and two strings specifying labels for the horizontal and vertical axes. The default
value is (0,0).
• ptype is a command name specifying the plot type. Executing the command FUNCTION
places the name FUNCTION in PPAR.
• depend is a name specifying a label for the vertical axis. The default value is Y.
The current equation is plotted as a function of the variable specified in indep. The minimum and
maximum values of the independent variable (the plotting range) can be specified in indep;
otherwise, the values in (x
between plotted points unless flag –31 is set.
If EQ contains an expression or program, the expression or program is evaluated in Numerical
Results mode for each value of the independent variable to give the values of the dependent
variable. If EQ contains an equation, the plotting action depends on the form of the equation, as
shown in the following table.
Form of Current Equation
expr = expr
name = expr
indep = constant
If flag –28 is set, all equations are plotted simultaneously.
If the independent variable in the current equation represents a unit object, you must specify the
units by storing a unit object in the corresponding variable in the current directory. For example,
if the current equation is X+3_m, and you want X to represent some number of inches, you
would store 1_in (the number part of the unit object is ignored) in X. For each plotted point, the
numerical value of the independent variable is combined with the specified unit (inches in this
3-70 Full Command and Function Reference
{ (x
, y
min
min
) is a complex number specifying the lower left corner of PICT (the lower left corner
min
) is a complex number specifying the upper right corner of PICT (the upper right
max
, y
) and (x
min
min
Each expression is plotted separately. The intersection of
the two graphs shows where the expressions are equal.
Only the expression is plotted.
A vertical line is plotted.
) (x
, y
) indep res axes ptype depend }
max
max
, y
)(the display range) are used. Lines are drawn
max
max
Plotting Action