HP 48gII Graphing, 50g Graphing manual Fourier, Freeze, Xunit Yunit Symb FPsymb

FOURIER

Type: Function

Description: Returns the nth coefficient of a complex Fourier series expansion. The PERIOD variable must be in the CAS directory, CASDIR, or in current path, and set to hold L, the period of the input function. The expression is expanded in terms of the current CAS variable.

Access: Calculus !ÖDERIV. & INTEG.

Input: Level 1/Argument 2: An expression in terms of the current variable Level 2/Argument 1: The number, n, of the coefficient to return.

Output: The nth Fourier coefficient of the expression.

Flags: Exact mode must be set (flag –105 clear). Numeric mode must not be set (flag –3 clear). Radians mode must be set (flag –17 set).

Complex mode must be set, that is, flag –103 must be set.

Example: Obtain the Fourier coefficient as below, with the default value of 2π in the PERIOD variable in CASDIR, and simplify it with EXPAND:

Command:	FOURIER(X^2,0)
	EXPAND(ANS(1))
Result:	4/3* π^2
FP	Function
Type:
Description:	Fractional Part Function: Returns the fractional part of the argument.
	The result has the same sign as the argument.
Access:	!´REAL LFP		( ´is the leftshift of the Pkey).
Flags:	Numerical Results (–3)
Input/Output:
		Level 1/Argument 1		Level 1/Item 1
		x	→	y
		x_unit	→	y_unit
		'symb'	→	'FP(symb)'
	32.3 FP
Example 1:		returns .3 .
Example 2:	32.3_m FP returns .3_m.
See also:	IP
FREE	Command
Type:
Description:	Do not use this command, a carryover from the HP 48SX for handling plugin RAM cards.
Access:	…µFREE
FREEZE	Command
Type:
Description:	Freeze Display Command: Freezes the part of the display specified by ndisplay area, so that it is not
	updated until a key is pressed.
	Normally, the stack display is updated as soon as the calculator is ready for data input. For
	example, when HALT stops a running program, or when a program ends, any displayed messages

are cleared. The FREEZE command “freezes” a part or all of the display so that it is not updated until a key is pressed. This allows, for example, a prompting message to persist after a program halts to await data input.

ndisplay area is the sum of the value codes for the areas to be frozen:

Full Command and Function Reference 391