yes.. but from the simple test I did, I felt L-BFGS is faster. Will confirm
anyway.

On Sun, May 31, 2015 at 10:13 PM, Upul Bandara <[email protected]> wrote:

> Actually, I'm thinking in terms of training time, even for large data sets
> prediction accuracy of L-BFGS will outperform SGD. But its training time
> would be considerably bigger than the training time of SGD.
> On the other hand, SGD model gives a decent prediction accuracy in
> relatively short period of training time.
>
>
> On Sun, May 31, 2015 at 9:52 PM, Nirmal Fernando <[email protected]> wrote:
>
>> Thanks Upul. So, are you thinking along the lines of performance? Sure,
>> I'll run a test.
>>
>> On Sun, May 31, 2015 at 9:50 PM, Upul Bandara <[email protected]> wrote:
>>
>>> If it is possible, I would like to have both.
>>>
>>> L-BFGS converges faster than SGD. But it goes through the entire data
>>> set before moving from one iteration to the next.
>>> Whereas, SGD uses a minit-batch of the training data set for calculating
>>> and updating its gradient.
>>> Hence, for large data sets SGD is more practical than L-BFGS.
>>>
>>> I think we can test this scenario by running these two algorithms
>>> against a large data set (~ 1GB)
>>>
>>> Thanks,
>>> Upul
>>>
>>> On Sun, May 31, 2015 at 8:02 PM, Nirmal Fernando <[email protected]>
>>> wrote:
>>>
>>>> One other benefit of switching is, this API supports multi-class
>>>> classification too. I've tested this API with Iris dataset.
>>>>
>>>> On Sun, May 31, 2015 at 7:33 PM, Nirmal Fernando <[email protected]>
>>>> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> Currently in ML, we use mini-batch gradient descent algorithm when
>>>>> running logistic regression. But Spark-mllib recommends L-BFGS over
>>>>> mini-batch gradient descent for faster convergence [1].
>>>>>
>>>>> I tested both the implementation with the same dataset and gained an
>>>>> improved accuracy in L-BFGS (80% vs 67% for SGD).
>>>>>
>>>>> Shall we switch?
>>>>>
>>>>> [1]
>>>>> https://spark.apache.org/docs/latest/mllib-linear-methods.html#logistic-regression
>>>>>
>>>>>
>>>>> --
>>>>>
>>>>> Thanks & regards,
>>>>> Nirmal
>>>>>
>>>>> Associate Technical Lead - Data Technologies Team, WSO2 Inc.
>>>>> Mobile: +94715779733
>>>>> Blog: http://nirmalfdo.blogspot.com/
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>>
>>>> Thanks & regards,
>>>> Nirmal
>>>>
>>>> Associate Technical Lead - Data Technologies Team, WSO2 Inc.
>>>> Mobile: +94715779733
>>>> Blog: http://nirmalfdo.blogspot.com/
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Upul Bandara,
>>> Associate Technical Lead, WSO2, Inc.,
>>> Mob: +94 715 468 345.
>>>
>>
>>
>>
>> --
>>
>> Thanks & regards,
>> Nirmal
>>
>> Associate Technical Lead - Data Technologies Team, WSO2 Inc.
>> Mobile: +94715779733
>> Blog: http://nirmalfdo.blogspot.com/
>>
>>
>>
>
>
> --
> Upul Bandara,
> Associate Technical Lead, WSO2, Inc.,
> Mob: +94 715 468 345.
>



-- 

Thanks & regards,
Nirmal

Associate Technical Lead - Data Technologies Team, WSO2 Inc.
Mobile: +94715779733
Blog: http://nirmalfdo.blogspot.com/
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