From a text file containing three columns of data I want to be able to just take a slice of data from all three columns where the values in the first column are equal to the values defined in above. I then want to put the slice of data into a new array called slice (I am using Python 2.7)
above = range(18000, 18060, 5)
data = np.loadtxt(open('data.txt'), delimiter=None)
energies = (np.hsplit(data, 3))[0]
slice = set(energies)&set(above)
The above comes back with:
Traceback (most recent call last):
File "<pyshell#27>", line 1, in <module>
set(energies)&set(above)
TypeError: unhashable type: 'numpy.ndarray
Your variable energies probably has the wrong shape:
>>> from numpy import array
>>> set([1,2,3]) & set(range(2, 10))
set([2, 3])
>>> set(array([1,2,3])) & set(range(2,10))
set([2, 3])
>>> set(array([[1,2,3],])) & set(range(2,10))
Traceback (most recent call last):
File “”, line 1, in
TypeError: unhashable type: ‘numpy.ndarray’
And that’s what happens if you read columnar data using your approach:
>>> data
array([[ 1., 2., 3.],
[ 3., 4., 5.],
[ 5., 6., 7.],
[ 8., 9., 10.]])
>>> hsplit(data,3)[0]
array([[ 1.],
[ 3.],
[ 5.],
[ 8.]])
Probably you can simply use
>>> data[:,0]
array([ 1., 3., 5., 8.])
instead.
(P.S. Your code looks like it’s undecided about whether it’s data or elementdata. I’ve assumed it’s simply a typo.)