spenczar commented on issue #35620:
URL: https://github.com/apache/arrow/issues/35620#issuecomment-1550029592
`6340900000` is much larger than a 32-bit floating point value can represent
exactly. A 32-bit `float` value has 23 bits of mantissa so you can only
represent exact integers up to 2**23 == 8,388,608.
If you want exact arithmetic at your scale, use the 64-bit `double` type:
```py
def test_minimal_viable():
import pyarrow as pa
import pyarrow.compute as pc
first = pa.chunked_array(pa.array([63409]))
last = pa.chunked_array(pa.array([35299]))
intsum = pc.add(
pc.multiply(first.cast('int32'), pa.scalar(100000)),
last.cast('int32')
)
floatsum = pc.add(
pc.multiply(first.cast('double'), pa.scalar(100000)),
last.cast('double')
)
raise Exception(f"""PyArrow Float Addition Error
I am attempting to add {pc.multiply(first,100000)} and {last}.
When I convert them to integer they yield: {intsum}
When I convert them to double they yield: {floatsum}
""")
```
yields
```sh
I am attempting to add [
[
6340900000
]
] and [
[
35299
]
].
When I convert them to integer they yield: [
[
6340935299
]
]
When I convert them to double they yield: [
[
6340935299
]
]
```
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