Float
DIM Var AS Float
This native datatype represents a double floating point value, i.e. a eight bytes floating point value.
The value of a Float is a number between -8.98846567431105E+307 and +8.98846567431105E+307
The precision of Float is 52 binary digits, which is 16 decimal digits (2^-52).
This means: if add to 1.0 a (positive) number which is less than 2E-16 than the result will be exactly 1.0
Example
DIM x AS Float = Sin(0.32)
DIM y AS Float = x - (0.32 - 0.32 ^ 3 / (2 * 3))
PRINT x;;y
0.314566560616 2.789394945107E-5
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Overflow during Float arithmetic operations is not detected!
Instead the result is set to 1E+2147483647 resp -1E+2147483647
If such an overflowed number is used in further expressions, then the execution stops and a message window shows "Mathematic error". But the value of a Float can be compared against maxfloat or minfloat.
|
CONST maxfloat AS Float = +8.98846567431105E+307
CONST minfloat AS Float = -8.98846567431105E+307
...
IF y > maxfloat OR y < minfloat THEN
PRINT "Float y overflow"
ELSE
x = y / 23000
ENDIF
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