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 DERIV. & 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 left-shift 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)'

 

 

 

 

 

Example 1:

-32.3 FP returns -.3.

 

 

Example 2:

32.3_m FP returns .3_m.

 

 

See also:

IP

 

 

FREE

Command

 

 

Type:

 

 

Description:

Do not use this command, a carry-over from the HP 48SX for handling plug-in 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 3-91