Hello! I am working on a package to parse FCS files (data file from flow
cytometry experiments) and got stuck when I got to parsing the data segment of
a FCS file.
import streams
var s = newFileStream("a2006_O1T2pb05i_A1_A01.fcs", fmRead) # download this
file here: https://flowrepository.org/experiments/3/fcs_files/21/download
s.setPosition(3705) # start position of data segment is stored in the
header segment
echo readFloat32(s)
s.close()
This gives me -2.084565955368639e+24, but the expected value is 23406.45.
In python, we can get the right value by specifying the byte order like this:
from struct import unpack
s = open("a2006_O1T2pb05i_A1_A01.fcs", "rb")
s.seek(3705)
print(unpack('>f', s.read(4))) # '>' denotes big-endian
s.close()
struck's unpack function allows users to specify the byte order in the first
argument, and I get the right value.
(23406.451171875,)
**_Is there a way to specify byte order when reading a binary file in a similar
way to python?_**
* * *
* [What is a FCS file?](https://en.wikipedia.org/wiki/Flow_Cytometry_Standard)
* [struct documentation](https://docs.python.org/3/library/struct.html)
* byte order information is stored in the text segment of the file.
