Re: [Numpy-discussion] fastest way to make two vectors into an array

Jan. 29, 2003


      On Wed, 29 Jan 2003, John Hunter wrote:
...
I have two equal length 1D arrays of 256-4096 complex or floating
point numbers which I need to put into a shape=(len(x),2) array.
I need to do this a lot, so I would like to use the most efficient
means.  Currently I am doing:
def somefunc(x,y):
    X = zeros( (len(x),2), typecode=x.typecode())
    X[:,0] = x
    X[:,1] = y
    do_something_with(X)
Is this the fastest way?
May be you could arange your algorithm so that you first create
X and then reference its columns by x,y without copying:

# Allocate memory
X = zeros( (n,2), typecode=.. )

# Get references to columns
x = X[:,0]
y = X[:,1]

while 1:
  do_something_inplace_with(x,y)
  do_something_with(X)

Pearu

Re: [Numpy-discussion] fastest way to make two vectors into an array

Pearu Peterson