FINITE Function

Returns a value indicating if the input variable is finite or not.

Usage

result = FINITE(x)

Input Parameters

x—A scalar or array expression of single-precision complex, double-precision complex, single-precision floating point, or double-precision floating point data type.

Returned Value

result—Returns 1 if x is finite. Returns 0 if x is infinite or not a defined number (NaN). Undefined numbers result from ill-defined operations, such as dividing zero by zero, or taking the logarithm of zero or a negative number.

Keywords

None.

Example 1

x = [100, SQRT(-1), ALOG(0), 99.9]
PM, x
; On UNIX systems, PV-WAVE prints:
;      100.000
;          NaN
;         -Inf
;      99.9000
; On Windows systems, PV-WAVE prints:
;       100.000
;      -1.#IND0
;      -1.#INF0
;       99.9000
PM, FINITE(x)
; PV-WAVE prints:
;       1
;       0
;       0
;       1

Example 2

; Note: This example requires PV-WAVE Advantage.
; Get the single-precision, floating-point machine constants.
MATH_INIT
fmach = MACHINE(/Float)
; Create a five-element vector containing single-precision, 
; floating-point NaN, positive infinity, negative infinity, and 
; finite values.
a = [fmach.nan, 3.0, fmach.pos_inf, 5.2, fmach.neg_inf]
b = FINITE(a)
; View result of FINITE.
INFO, b
; PV-WAVE prints: B          BYTE         = Array(5)

; Print vectors a and b. Note that vector b contains a 0
; when NaN or infinity occurs in a. Vector b contains 1 at
; the indices where vector a contains finite values.
FOR i=0L, 4 DO PRINT, a(i), b(i)
; On UNIX systems, PV-WAVE prints: 
;   NaN       0
;   3.00000   1
;   Inf       0
;   5.20000   1
;   -Inf      0
; On Windows systems, PV-WAVE prints: 
;   1.#QNAN   0
;   3.00000   1
;   1.#INF0   0
;   5.20000   1
;  -1.#INF0   0