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How to (natively) perform PCA feature selection given eigenvectors & decamp scores

I’m trying to do feature selection using PCA in Java without a ML framework, just using the Apache math matrix library. The input test data is a 2D array, 4 feature cols x 100 row instances. Roughly i’ve gone through the following steps: Load the data, normalise, store in the RealMatrix class and calculate the […]

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does anything get executed when i extend from an abstract class?

i’m currently reading the 3rd version of bignerdranch android book, i don’t have any problem executing the codes , but i really want to know how abstract class works here. i have an activity class that extends from an abstract class to create fragments . most of the job is done in the abstract class […]

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BATCH – can’t return proper value in a variable from a function

I have read a lot of examples and questions about returning values from batch functions using variables but I can’t force Windows 7 x64 cmd.exe to do it for me. 😉 I have already tried a lot of code examples but nothing has worked as I expected. I have written a short batch program to […]

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find the overlapping dates between different date ranges

The problem is the find the overlapping dates between different date ranges. Here while comparing first two date ranges the overlapping dates are 09/Jan/2018, 10/Jan/2018 and while comparing all the three date ranges the overlapping date is 10/Jan/2018. Is there a way to find it in Excel, R-programming, Python or any ? START_DATE END_DATE Overlapping_Date […]

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Distinct event types on same collection – MongoDB and .NET Core

I want to use MongoDB to store domain events in a system written with .NET Core and C#. I’ve googled a little about this, and it seems it is a common practice to have a single collection called events and simply store all events there. I’ve also seem people to create one field type to […]

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‘Cannot resolve symbol’ (design + v7 + annotation)

A friend of mine sent me some activity from his app. I created a new activity for each one and copy-paste the code in the new empty activity. Now I got some problem with the imports: import android.support.design.widget.TextInputEditText; import android.support.design.widget.TextInputLayout; import android.support.v7.widget.RecyclerView; import android.support.annotation.Nullable; And here there is my Gradle – app: apply plugin: ‘com.android.application’ […]

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Start-up activity cannot be changed

I wish to change the start-up activity of my app from Main to Start. This is the present code section in the Manifest, which starts the app up with activity Main. No problem. <activity android:name=”.Main” android:label=”Input Page”> <intent-filter> <action android:name=”android.intent.action.MAIN” /> <category android:name=”android.intent.category.LAUNCHER” /> </intent-filter> </activity> <activity android:name=”.Stats” android:label=”Match Report Page” /> <activity android:name=”.Settings” android:label=”Settings […]

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Disable the cleaning of std::shared_ptr

I am currently refactoring some old parts of a code. The method I am working on is heavily using the new and delete features in order to achieve its purpose. I could easily replace all that with shared pointers for better code clarity and safety. The thing is, that in the end I need to […]

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Is there a way to make this python selenium code work in headless mode?

So I asked this question earlier (Unable to get selenium (python) to download a csv file which doesnt have a link but only appears after i click the download button) and managed to get this far. I finally realised that the code wasnt working because it was in headless mode. In my earlier post I […]

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How to enter state array and sum objects’ props?

That is the code: I have order array in state, table which map it ,and now i need to summarize prices which are inside objects in array. It should be counted in “handleCount” function,without adding any extra state objects, and return true cost of orders. Then “newPrice”-(which store cost)should be passed to “handleSubmit function. const […]