floating point library ?

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vasile surducan

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Oct 30, 2012, 3:57:47 AM10/30/12
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Hi all,

I'm starting a project (gathering information till now) about interfacing an IR array sensor MLX90620

The problem is that MLX90620 require serious computational algorithms given by the Stefan-Boltzmann law, including a fourth order square root for temperature computation. Probably this can be done with long fixed point math, I didn't tested anything yet, but will be difficult anyway...

There is some experience here with any floating point library (including assembler) which has been successfully used with jal?

thx,
Vasile


Joep Suijs

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Oct 30, 2012, 4:44:23 AM10/30/12
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Hi Vasile,

I did some experiments with floating point math in JAL. it supports
add, subtract, multiply and divide and support functions for assign,
print (basic scientific notation only), and conversion to int
(actually, sdword). Compare functions (check for sign, zero etc) might
be usefull to add, and so might more enhanced printing functions
(scientific notation with exponenten multiples of 3, normal
presentation with a comma).
Floats are stored dwords, 24 bits for the signed mantissa and 8 bit
for the signed exponent.
It works okay, but it is of course large and not (yet) optimized for
speed, so I doubt it will meet your standards ;) Sunish has a copy but
I don't know if he actual used it yet.
I won't release it into the open source (yet), but if a more
restricted license (not allowing commercial use) is not a problem, I'm
happy to make it available to you.

Regards,
Joep

2012/10/30 vasile surducan <vsur...@gmail.com>:
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Sunish Issac

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Oct 30, 2012, 6:24:14 AM10/30/12
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No Joep,
I did not use it as fixed point solved my issues.

Thanks,

Sunish

vasile surducan

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Oct 30, 2012, 6:31:57 AM10/30/12
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Hi Joep,

I'm not working for commercial use, I'm planning to design a microwave applicator with a built in IR radiometer for our research purposes (will probably do two things: emitting power microwaves and measuring the temperature of the heated surface). I do not know if I'll use your library, however I will love to take a look, and maybe to evaluate some routines during the tests. 

thank you,
Vasile
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