Laszlo Nagy wrote:
Attached there is an example program that only requires numpy. At the end I have two numpy array:

rdims:

[[3 1 1]
[0 0 4]
[1 3 0]
[2 2 0]
[3 3 3]
[0 0 2]]


rmeas:

[[100000.0 254.0]
[40000.0 200.0]
[50000.0 185.0]
[5000.0 160.0]
[150000.0 260.0]
[20000.0 180.0]]


I would like to use numpy to create statistic, for example the mean value of the prices:

 >>> rmeas[:,0] # Prices of cars
array([100000.0, 40000.0, 50000.0, 5000.0, 150000.0, 20000.0], dtype=float96)
 >>> rmeas[:,0].mean() # Mean price
60833.3333333333333321

However, I only want to do this for 'color=yellow' or 'year=2003, make=Ford' etc. I wonder if there a built-in numpy method that can filter out rows using a set of values. E.g. create a view of the original array or a new array that contains only the filtered rows. I know how to do it from Python with iterators, but I wonder if there is a better way to do it in numpy. (I'm new to numpy please forgive me if this is a dumb question.)

It's not, but you will get more help on the numpy-discussion mailing list than 
here.

  http://www.scipy.org/Mailing_Lists

I would normally answer your question, too, but I'm on vacation and have to run off to a party right now.

--
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless enigma
 that is made terrible by our own mad attempt to interpret it as though it had
 an underlying truth."
  -- Umberto Eco

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