I don't think you can make any statements about the optimization method
wrt the data
when you don't specify the loss function you want to minimize.
On 04/25/2013 03:10 PM, Ronnie Ghose wrote:
I think he means what increases/benefits do you get from rescaling
features e.g. minmax or
Even scikit-learn mentions on its stochastic gradient descent page:
http://scikit-learn.org/dev/modules/sgd.html#tips-on-practical-use
one should scale data. An example which shows what really happens to one
cost function (say squared loss) on scaling the data would be great.
On 26-04-2013
afaik fits tend to work better and so do classifiers. it's much easier to
have a classifier try to fit between -1 and 1 then 0 and 1 so it also
helps convergence.
http://stats.stackexchange.com/questions/41704/how-and-why-do-normalization-and-feature-scaling-work
and then
(first-order) GD uses a single learning rate for all features - if features
have a different variability its difficult to find a one-size-fits-all
learning rate - the parameters of high variability features will tend
to oscillate whereas the parameters of low variability features will
converge too
@Shishir Pandey on a slight tangent, what problems are you having with
running Libsvm GUI?
I wonder if a GUI interactive example would really be necessary - we could
just have an example
illustrating the difference with plots when data is not scaled or scaled..
if people find that useful.
But the
@Jaques Grobler: I ran the libsvm GUI code on the sklearn version 13.1
it was giving error importing - from sklearn.externals.six.move import
xrange. But I commented the above line and it is working just fine.
As you have suggested GUI example might not really be that necessary.
Illustrating
On Fri, Apr 26, 2013 at 04:17:36PM +0530, Shishir Pandey wrote:
@Jaques Grobler: I ran the libsvm GUI code on the sklearn version 13.1
it was giving error importing - from sklearn.externals.six.move import
xrange.
Which error? Could you copy/paste it here?
G
From what you are saying, the independent variables are the parameters of
the cost function. It is your search space, right?
If you change the scale, of course the gradient descent behavior will be
different. Also, if the input parameters are scaled properly, (let's say
that the variables that had
I also think it will be great to have this example on the website.
Do you mean like an interactive example that works similiar to the SVM Gui
examplehttp://scikit-learn.org/dev/auto_examples/applications/svm_gui.html#example-applications-svm-gui-py
,
but for
understand the effects shifting and
On Thu, Apr 25, 2013 at 02:09:13PM +0200, Jaques Grobler wrote:
I also think it will be great to have this example on the website.
Do you mean like an interactive example that works similiar to the SVM
Gui example , but for understand the effects shifting and scaling of
data has on the rate
I think he means what increases/benefits do you get from rescaling features
e.g. minmax or preprocessing.scale
On Thu, Apr 25, 2013 at 02:09:13PM +0200, Jaques Grobler wrote:
I also think it will be great to have this example on the website.
Do you mean like an interactive example that works
Thanks Ronnie for pointing out the exact method in the scikit-learn
library. Yes, that is exactly what I was asking how does the rescaling
of features affect the gradient descent algorithm. Since, stochastic
gradient descent is an algorithm which is used in machine learning quite
a lot. It
Hi,
Do you mean scaling the parameters of the cost function? If so, scaling
will change the surface of the cost function, of course. It's kind of
complicated to say anything about how the surface will behave, it
completely depends of the cost function you are using. A cost function that
is linear
I did not mean parameters of the cost function. I only want to scale the
input variables. Suppose one of the independent variables has a range
from 10 - 1000 and some other has a range in 0.1 - 1. Then Andrew Ng and
others say in their machine learning lectures that one should rescale
the
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