python - Why am I allowed pickle instancemethods that are Theano functions, but not normal instancemethods? -


in process of using joblib parallelize model-fitting code involving theano functions, i've stumbled across behavior seems odd me.

consider simplified example:

from joblib import parallel, delayed import theano theano import tensor te import numpy np  class theanomodel(object):     def __init__(self):         x = te.dvector('x')         y = (x ** te.log(x ** 2)).sum()         self.theano_get_y = theano.function([x], y)      def get_y(self, x):         return self.theano_get_y(x)  def run(niter=100):     x = np.random.randn(1000)     model = theanomodel()     pool = parallel(n_jobs=-1, verbose=1, pre_dispatch='all')      # fails `typeerror: can't pickle instancemethod objects`...     results = pool(delayed(model.get_y)(x) _ in xrange(niter))      # # ... works! why?     # results = pool(delayed(model.theano_get_y)(x) _ in xrange(niter))  if __name__ == '__main__':     run()

i understand why first case fails, since .get_y() instancemethod of theanomodel. don't understand why second case works, since x, y andtheano_get_y() declared within __init__() method of theanomodel. theano_get_y() can't evaluated until theanomodel instance has been created. surely, then, should considered instancemethod, , should therefore unpickleable? in fact, still works if explicitly declare x , y attributes of theanomodel instance.

can explain what's going on here?

update

just illustrate why think behaviour particularly weird, here few examples of other callable member objects don't take self first argument:

from joblib import parallel, delayed import theano theano import tensor te import numpy np  class theanomodel(object):     def __init__(self):         x = te.dvector('x')         y = (x ** te.log(x ** 2)).sum()         self.theano_get_y = theano.function([x], y)         def square(x):             return x ** 2         self.member_function = square         self.static_method = staticmethod(square)         self.lambda_function = lambda x: x ** 2  def run(niter=100):     x = np.random.randn(1000)     model = theanomodel()     pool = parallel(n_jobs=-1, verbose=1, pre_dispatch='all')      # # not allowed: `typeerror: can't pickle function objects`     # results = pool(delayed(model.member_function)(x) _ in xrange(niter))      # # not allowed: `typeerror: can't pickle function objects`     # results = pool(delayed(model.lambda_function)(x) _ in xrange(niter))      # # not allowed: `typeerror: can't pickle staticmethod objects`     # results = pool(delayed(model.static_method)(x) _ in xrange(niter))      # totally fine!?     results = pool(delayed(model.theano_get_y)(x) _ in xrange(niter))  if __name__ == '__main__':     run()

none of them pickleable exception of theano.function!

theano functions aren't python functions. instead python objects override __call__. means can call them function internally objects of custom class. in consequence, can pickle them.


Comments

Post a Comment

Popular posts from this blog

javascript - Jquery show_hide, what to add in order to make the page scroll to the bottom of the hidden field once button is clicked -

i have button on website when clicked, reveals map. button can seen when page first loads up, when clicked, section holding map slides open , goes out of screen since page loads @ top (normal). want page scroll down bottom of div select when button pushed, if map out of screen. if page scrolled down, , clicks show map button, don't want page jump bottom of map. i tried figure out myself, no luck. seasoned jquery coders able give me guidance? many thanks! map = mapdiv.gmap3("get"); infobox = new infobox({ pixeloffset: new google.maps.size(-220, -310), closeboxurl: '', enableeventpropagation: true }); mapdiv.delegate('.infobox .close','click',function () { infobox.close(); }); jquery(".slidingdiv").hide(); jquery(".show_hide").show(); jquery('.show_hide').click(function(){ lastcenter=map.getcenter(); jquery(".slidingdiv...
Read more

python - Django-cities exits with "killed" -

i trying install django-cities on server 500mb ram. whenever run: manage.py cities the system exits saying killed. trying run: manage.py cities --import=country --force worked, guessing matter of running out of memory. to bypass, tried refer package local copy of cities' data file. still didn't work. any ideas on how can migrate data without having increase memory on server? based on suggestion comments, solved setting temporary swap file. if unfamiliar it, can follow these steps: set swap file touch /var/swap.img chmod 600 /var/swap.img set swap file size cd /var dd if=/dev/zero of=/var/swap.img bs=1024k count=1000 this create 1gb swap file. prepare disk image mkswap /var/swap.img activate swap memory swapon /var/swap.img once done, can turn off swap image: swapoff /var/swap.img more information on virtual memory , swap files can found here: https://www.digitalocean.com/community/tutorials/how-to-configure-virtual-me...
Read more

python - How to get a widget position inside it's layout in Kivy? -

i have gridlayout , added image widgets on after adding of images want draw rectangle in each image using canvas couldn't because don't know exact image widgets positions on gridlayout. code: http://paste.ofcode.org/3bdp9yhjrcrzmsztbu9hqp4 http://paste.ofcode.org/3az3gx4fxzr9dlhe2ami97c in last line of python code : rectangle(pos = (child.x - 2.4, child.y + 467), size = (70, 70)) how draw rectangle in child(my method not good^), also why gridlayout not coming in center after setting it's pos_hint = {"center_x" : .5}? if understand question right, try use such methods to_local() , to_parent() , to_widget() , to_window() . try substract position of gridlayout widgets' positions.
Read more