Now I am trying to read the array in the file named "filin1" such as:
filin1 = [1,3,4, ....,nan,nan,nan..] (in the file, actually it is just a column not an array like this)
So, I am trying to use numpy.genfromtxt as:
np.genfromtxt(filin1,dtype=None,delimiter=',',usecols=[0],missing_values='Missing',usemask=False,filling_values=np.nan)
I expected to get [1,3,4, ....,nan,nan,nan..], but turned out to be:
[1,3,4, ....,0.,0.,0...]
I would like to hold 'nan' without converting it to '0.'.
Would you please give any idea or advice?
Thank you, Isaac
If I try to simulate your case with a string input, I have no problem reading the nan
In [73]: txt=b'''1,2
3,4
1.23,nan
nan,02
'''
In [74]: txt=txt.splitlines()
In [75]: txt
Out[75]: [b'1,2', b'3,4', b'1.23,nan', b'nan,02']
In [76]: np.genfromtxt(txt,delimiter=',')
Out[76]:
array([[ 1. , 2. ],
[ 3. , 4. ],
[ 1.23, nan],
[ nan, 2. ]])
nan is a valid float value
In [80]: float('nan')
Out[80]: nan
Your command works also, though it does
In [82]: np.genfromtxt(txt,dtype=None,delimiter=',',usecols=[0],missing_values='Missing',usemask=False,filling_values=np.nan)
Out[82]: array([ 1. , 3. , 1.23, nan])
Expecting the columns to contain integers (rather than float) could cause problems, since nan is a float, not int.
And missing values result in nan with both calls
In [91]: txt
Out[91]: [b'1,2', b'3,', b'1.23,nan', b'nan,02', b',']