ZBasicSysLib - page 308 of 361

Page 308 of 361

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ZBasic System Library

ZBasic Microcontrollers

Function returning Byte

The value of which to determine the floating point classification.

The IEEE 754 standard floating point format used by ZBasic specifies a set of classifications for floating

point values. This function returns a numeric value indicating the class to which the passed Single

value belongs. The table below enumerates the return values and describes the meaning of each.

Floating Point Value Classes

Normalized - This class represents “normal” floating point values

such as 1.537 but does not include 0.0.

Zero - This class represents the zero value (positive and

Infinity - This class represents positive and negative infinity.

Dividing a positive value by zero results in positive infinity.

Denormalized - This class represents an internal form known as

denormalized values. Such values should never be generated

as a result of a floating point operation. However if you copy

some random bytes into a floating point variable the result may

be a denormalized value.

NaN - This class represents values that are “Not A Number”.

Taking the square root of a negative value or the logarithm of

zero results in a NaN.

The names in the first column are available as built-in constants. Except for ClassNaN, the return value

may include the flag &H80 to indicate a negative value. For example, SngClass(-1.0) returns the

value &H81 to indicate a negative ClassNormal value. The built-in constant representing the negative

flag is ClassNegative. The built-in constant ClassMask may be used to remove the negative flag from the

return value, e.g. SngClass(fval) And ClassMask.

Dim class as Byte

class = SngClass(1.0)

class = SngClass(-1.0)

' result is &H81

class = SngClass(-1.0) And ClassMask ' result is 1

class = SngClass(Sqr(-1.0))

class = SngClass(1.0 / 0.0)

This function is not available in BasicX compatibility mode.