Float64 failing to write/read?

Dryopes

Hi,

I am working with a database with plenty of float64 operations, and I have trouble comparing these floats which each other when reading/writing from the database. A simple example of this is as follows:

import dataiku
import pandas as pd

df = pd.DataFrame(data = {'a' : [3222.232343243847737]})
db = dataiku.Dataset("test")

db.write_with_schema(df)
df2 = db.get_dataframe()

print(df.values[0][0] == df2.values[0][0])

1 rows successfully written (L26vwn5Fzw)
False

Here it seems that the floating value seem to change in the process of reading/writing the database. Am I doing something wrong, is this expected behavior?

tgb417

@Dryopes
,

Welcome to the Dataiku Community, glad to have you here.

A while back I ran into something similar. Not clear if it will be your problem or not.

What was explained to me was a binary encoding rounding error. But I think in my example I had a division.

See if you put a round() function around things out to say 15 places if the problem resolves.

That said I’d also encourage you to put in a support ticket. If you have found a defect it would be great to get this in the backlog with the development team.

Here is a somewhat longer discussion on this topic. https://community.dataiku.com/t5/General-Discussion/Precision-on-Mathematical-formulas-on-a-recipe/td-p/18058