[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

On 05/18/2018 09:50 PM, Sharan Basappa wrote: > This is regarding numpy array. I am a bit confused how parts of the array are being accessed in the example below. > > 1 import scipy as sp > 2 data = sp.genfromtxt("web_traffic.tsv", delimiter="\t") > 3 print(data[:10]) > 4 x = data[:,0] > 5 y = data[:,1] > > Apparently, line 3 prints the first 10 entries in the array > line 4 & 5 is to extract all rows but only 1st and second columns alone for x and y respectively. > > I am confused as to how data[:10] gives the first 10 rows while data[:,0] gives all rows > Numpy ordering is [rows,columns,...]. Things you don't provide an explicit answer for are assumed to be "all", which in Python syntax is ":". The reason for THAT goes into how slices are constructed. So your example 3 could also be written print(data[0:10,:]), which sets rows to the range starting with 0 and ending before 10, and columns to everything. -- Rob Gaddi, Highland Technology -- www.highlandtechnology.com Email address domain is currently out of order. See above to fix.

- Prev by Date:
**best way to remove leading zeros from a tuple like string** - Next by Date:
**"Data blocks" syntax specification draft** - Previous by thread:
**Numpy array** - Next by thread:
**EuroPython 2018: Call for Proposals closes on Sunday** - Index(es):