Big float in Micropython (ESP32)

[MUSQAR]

Hello everyone,


I'm going to use Big Float variable in Micropython(9 numbers after the 0.), after dividing between two numbers I got just 8 numbers in the result.

any information about this topic?

Thanks

[jimmo]

MicroPython uses regular IEEE single (or double in some ports) precision floating point. It's not an easy topic and it's mostly fairly counterintuitive.

This is a site that I see people link to a lot, https://floating-point-gui.de/ but there are lots of tutorials out there.

If you care about precision, you need to work entirely in integers, but for many situations you can get by with floats.

[miltmobley]

In cpython, this appears to require the bigfloat package to be installed. From Python docs, we have:
"The bigfloat package is a Python wrapper for the GNU MPFR library for arbitrary-precision floating-point reliable arithmetic."
If you really need such bigger numbers, you would have to port bigfloat module to micropython and the MPFR library to its C backends.
This could be a large amount of work.

If you only need nine digits instead of eight, a software fp implementation might make sense.
And if your micropython device is normally connected to a pc host, you might be able to implement a remote procedure call to have the
host do the calculations.

[miltmobley]

I just noticed there is also a "decimal" module in cpython which may do what you want, i.e. more than eight decimal places.
But if it's not in micropython,you would have to port it.