Needing A header file

[Mike Betts]

Originally Posted by jweric

the reason why I must use a float point is because I need to have correct values, saddly I cant do it any other way.

That is incorrect, you just are not aware of another way. Use fixed-point integer notation.

An example variable declaration could be:

integer max_v; // 2FX12 (0x1000 = 1 foot/sec)

In the above example, the resolution of the variable for maximum velocity is
0.003 inches per second and the variable ranges from + +7.99975 to -7.99975 feet per second.

Choose your number system with care and beware of overflowing variables in your calculations. Also realize that 0x8000 (negative zero) is not a number!

I assure you that the 2004 Bobcat has no floating-point variables and, sensor accuracy notwithstanding, the mathematical accuracy of our position is less than a tenth of an inch.

Best of luck,

[Jared Stofflett]

Can you give me a tutorial or example where I can learn more about this? ALl i've learned so far for decimal points is floating point data types. APpreciate any info.

[Mike Betts]

Originally Posted by Jared Stofflett

Can you give me a tutorial or example where I can learn more about this? ALl i've learned so far for decimal points is floating point data types. APpreciate any info.

Jared,

Unfortunately, everything I have is in books. You might try to google it.

Originally Posted by Jared Stofflett

Can you give me a tutorial or example where I can learn more about this? ALl i've learned so far for decimal points is floating point data types. APpreciate any info.

Did a Yahoo search and got for "floating point" and got this tutorial web address: http://www.cs.utah.edu/~zachary/isp/applets/FP/FP.html

Most important thing about floating point:

DO NOT use unless absolutely neccessary. Any computation with floating-point data (like floats or doubles) is much slower than the same operation with integers (like chars, ints, and longs).

Floating-point data is different than other data because the number that the data itself represents is not directly stored. Instead, a mantissa, sign, and exponent are stored. This is sort of like scientific notation where you know the exponent which for the base 10 and the multiplier. In floating-point, you store every number as:

[sign] [mantissa] x 2 ^ ([exponent])

The 2 is not stored because it is the same for every number. Sign is 0 if the number is positive, and 1 if the number is negative (only one bit stored). Exponents must account for both negative and positive exponents, hence the exponent has a bias. This means that a positive number is added to all exponents in order to make every possible exponent positive.

Mantissas, get information here: http://research.microsoft.com/~holla...ieeefloat.html

Hope this helps!

[Mike Betts]

Originally Posted by Jared Stofflett

Can you give me a tutorial or example where I can learn more about this? ALl i've learned so far for decimal points is floating point data types. APpreciate any info.

Did a quick google and found this: http://www.embedded.com/98/9804fe2.htm

It should get you started...