Campbell Scientific CR1000KD CR800 and CR850 Measurement and Control Systems - Page 144

CRBasic Example 20., Conversion of FLOAT / LONG to Boolean, CRBasic Example 21., Evaluation

Page 144 highlights

Section 7. Installation CRBasic Example 20. Conversion of FLOAT / LONG to Boolean Public Fa As Float Public Fb As Float Public L As Long Public Ba As Boolean Public Bb As Boolean Public Bc As Boolean BeginProg Fa = 0 Fb = 0.125 L = 126 Ba = Fa Bb = Fb Bc = L EndProg 'This will set Ba = False (0) 'This will Set Bb = True (-1) 'This will Set Bc = True (-1) FLOAT from LONG or Boolean When a LONG or Boolean is converted to FLOAT, the integer value is loaded into the FLOAT. Booleans are converted to -1 or 0. LONG integers greater than 24 bits (16,777,215; the size of the mantissa for a FLOAT) will lose resolution when converted to FLOAT. LONG from FLOAT or Boolean When converted to Long, Boolean is converted to -1 or 0. When a FLOAT is converted to a LONG, it is truncated. This conversion is the same as the INT function (Arithmetic Functions (p. 475) ). The conversion is to an integer equal to or less than the value of the float (e.g., 4.6 becomes 4, -4.6 becomes -5). If a FLOAT is greater than the largest allowable LONG (+2,147,483,647), the integer is set to the maximum. If a FLOAT is less than the smallest allowable LONG (-2,147,483,648), the integer is set to the minimum. Integers in Expressions LONGs are evaluated in expressions as integers when possible. CRBasic example Evaluation of Integers (p. 144) illustrates evaluation of integers as LONGs and FLOATs. CRBasic Example 21. Evaluation of Integers Public X, I As Long BeginProg I = 126 X = (I+3) * 3.4 'I+3 is evaluated as an integer, then converted to FLOAT before 'it is multiplied by 3.4 EndProg 144

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Section 7.
Installation
144
CRBasic Example 20.
Conversion of FLOAT / LONG to Boolean
Public
Fa
As Float
Public
Fb
As Float
Public
L
As Long
Public
Ba
As Boolean
Public
Bb
As Boolean
Public
Bc
As Boolean
BeginProg
Fa = 0
Fb = 0.125
L = 126
Ba = Fa
'This will set Ba = False (0)
Bb = Fb
'This will Set Bb = True (-1)
Bc = L
'This will Set Bc = True (-1)
EndProg
FLOAT from LONG or Boolean
When a
LONG
or
Boolean
is converted to
FLOAT
, the integer value is loaded
into the
FLOAT
.
Boolean
s are converted to
-1
or
0
.
LONG
integers greater than
24 bits (16,777,215; the size of the mantissa for a
FLOAT
) will lose resolution
when converted to
FLOAT
.
LONG from FLOAT or Boolean
When converted to
Long, Boolean
is converted to
-1
or
0
. When a
FLOAT
is
converted to a
LONG
, it is truncated. This conversion is the same as the
INT
function (
Arithmetic Functions
(p. 475)
). The conversion is to an integer equal to or
less than the value of the float (e.g., 4.6 becomes 4, -4.6 becomes -5).
If a
FLOAT
is greater than the largest allowable
LONG
(+2,147,483,647), the
integer is set to the maximum. If a
FLOAT
is less than the smallest allowable
LONG
(-2,147,483,648), the integer is set to the minimum.
Integers in Expressions
LONG
s are evaluated in expressions as integers when possible. CRBasic example
Evaluation of Integers
(p. 144)
illustrates evaluation of integers as
LONG
s and
FLOAT
s.
CRBasic Example 21.
Evaluation of Integers
Public
X, I As Long
BeginProg
I = 126
X = (I+3) * 3.4
'I+3 is evaluated as an integer, then converted to FLOAT before
'it is multiplied by 3.4
EndProg