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Converting float64 to float32 rounds off data in hdu object
See original GitHub issueHi, Why do we round off the data to integers before changing the data type in this line? https://github.com/astropy/astropy/blob/5f88a0ede0d03cf6329d9d5e0971d540275a8b55/astropy/io/fits/hdu/image.py#L549
To save hardisk space, I wanted to convert my float64 fits images to float32.
I used the hdulist[0].scale('float32') method to do that.
However, instead of changing float64 to float32, it rounded off to nearest integer.
Issue Analytics
- State:
- Created 6 years ago
- Comments:7 (7 by maintainers)
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From what I understand the
.scalemethod should only be used to scale to (unsigned) int. (From the FITS standard, “Use of the BSCALE and BZERO keywords is not recommended” for floats).For a float64->float32 conversion, converting the data directly with
.astypeis the good way.@pllim , Yes. That is what I did now as a workaround. used the
.data.astype(), and it worked as expected.