[Numpy-discussion] extract elements of an array that are contained in another array?

Hi, I want to extract elements of an array (say, a) that are contained in another array (say, b). That is, if a=array([1,1,2,3,3,4]), b=array([1,4]), then I want array([1,1,4]). I did the following but the speed is very slow (maybe because a is very long): c=array([]) for x in b: c=append(c,a[

Re: [Numpy-discussion] extract elements of an array that are contained in another array?

Thanks! Tried it and it is about twice as fast as my approach. -Ning On Wed, Jun 3, 2009 at 7:45 PM, wrote: > On Wed, Jun 3, 2009 at 8:29 PM, Ning Sean wrote: > > Hi, I want to extract elements of an array (say, a) that are contained in > > another array (say, b). That