I have a CSV file containing data for a market-basket analysis. I have imported the file successfully to Weka, but I found that some attributes does not have any value, i.e., all values are missing. Weka don't let me use the Apriori algorithm with this data, so I would like to know if there is a way to remove those attributes from the imported data.
PS.: There are thousands of attributes, so I don't want to specify the attributes that need to be removed.
You can remove them using the "remove" filter in WEKA's Explorer.
Once the data has been loaded into WEKA:
1) Go to "Process" (1st main tab).
2) In "filter" area click "Choose" a filter.
3) Navigate through the tree to "filters" -> "unsupervised" -> "attribute" -> "Remove".
4) Once "Remove" filter has been chosen, click to "Remove" label next to "Choose" button, it will open a dialog.
5) Fill out the attributeIndices text field with the index/indices of the attributes to be removed, i.e. "1,4,10" or "1-3,7".
6) Click "OK" in the dialog and "Apply" button in the filter area of the main window.
That's all !!
I believe weka.filters.unsupervised.attribute.RemoveUseless might help
Related
I’m trying to use InfoGainAttributeEval in Weka for feature selection, how to save the result? I try to save it but seems like my weka just save my input data, not the result of feature selection.
Welcome to SO. As far as I understand you want to get the ranked values of the attributes. To do this, right click on the "Ranker + InfoGainAttributeEval" statement in the "Result List" section. Select "Save result buffer". You can see the results in programs such as notepad. You can also import it into "Excel" and create it in the chart. I think you selected "Ranker" in the Search Method section. I think it is an image as seen in the figure below.
After selecting and running "InfoGainAttributeEval" and "Ranker" it will give you a "ranked" list (Use full training set). Right click and select "Save Reduced Data" then save. Open the file in notepad as well. Open in Weka too. Select the ones whose Rank value is 0 in Weka and delete them with "Remove". Let those with rank value be left. Now you can get the same result reduced with these features. Save in .arff format. Now you have acquired Reduced data.
If "Save Reduced Data" is not working for you, here is another approach.
Attribute selection can be accomplished in the Preprocess tab.
There is a bar near the top for Filtering the data. Click the
"Choose" button. Under Filters->Supervised->Attribute you will
find AttributeSelection. Select that.
Once it says "AttributeSelection" in the Filter bar, you can click
on the bar to pick a selection method and a search method as well as
set the parameters for those choices.
Once you have made your choices for the feature selection algorithm,
click Apply to the right of the filter bar so that the filter is
actually applied to the data. The data should now have the reduced
feature set. So all you need to do is save it by clicking on the
Save button at the top right.
This should save the reduced data set.
I have several tabs. There is a date picker on each tab. I need that date to be the same on all tabs no matter what. So, if the user changes the date on Tab 1, then goes to tab 2, the date on tab 2 will have changed also. I have never created an application level item before and I thought that might be the most efficient way to accomplish what I need (by setting that item's value to the date the user selected). My problem is that I don't know how to set the value of the application item and also how to retrieve that value on another tab.
You didn't describe what exactly you're trying to do, but - if each tab represents its own table, why do you keep the same date value in all of them? Doesn't look like a normalized data model. Consider using a single date column (in one - master - table) and use (i.e. reference) it in others (i.e. details).
As of your question: How about creating a global page (i.e. page 0) and having a date picker item on it? You can display it on any other page you want. For example, if you set its value while on tab 1 and then move on to tab 3, you can again modify that value which will be visible on all other pages. Basically, you'd maintain just one item instead of as many as number of tabs involved. (BTW, doesn't that remind you of what I described in the first paragraph?).
Alternatively, create a date picker item on tab 1 page; on all other pages, create a "lookup" (display) item which would simply display what's been selected on tab 1. That's easy to do, just make its source to be an "Item", such as P1_DATE_ITEM.
In Shared Components > Application Items create new Item called G_DATE.
Then for every datepicker add Dynamic Action on Event Change.
In True action Set Value select Type PL/SQL Expression with code
:G_DATE := :P1_DATEPICKER1;
and Items to Submit :P1_DATEPICKER1
Next in every datepicker Source set Type PL/SQL Expression with code
:G_DATE
used Always (...)
Regards
I'm writing an application that will allow a user to drag/drop specific files onto the application window, parse those files, put the contents into a table (via a QStandardItemModel), and add each file's name (or alias) to a separate tree view (which acts as the document switcher).
I'll use NotePad++ as a simple example.
When I click any of the new files in the leftmost "Doc Switcher," it shows the contents in the right pane. Imagine that right pane is a table. And for instance, imagine that the list on the left is a list of .csv files that were imported into the application.
What I want to do is, upon clicking each item in the list, I want the corresponding parsed .csv file to show up in the table pane on the right.
My table is just a QTableView that displays the contents of the .csv files in a QStandardItemModel. Everything works when it comes to implementing the table and parsing the files.
I also set up a QTreeWidget as the "document switcher." Now, I need to link the document switcher selection to the table so that each file's respective contents will be shown in the table view.
I can have the application populate the tableView with the model contents when the QTreeView's top level item selection changes. That's no problem. The problem is with what I should be checking for when that selection changes and how.
I'm unsure of how to implement this. How do I store a bunch of QStandardItemModel objects and then link them to their names in the document switcher? Should I even be doing that? Do I have to create a new QStandardItemModel for each file that is imported? Should I create one QStandardItemModel, then somehow save it to be pulled back up later and re-use that same table model object for each file that is added? I'm just unsure how how this is supposed to work and feel like I am missing a fundamental part of all of this.
I would suggest two approaches to solve your problem:
You can watch document switcher signal (selection changed) and create new model for the currently selected data. Your table view in the right should show the data, when you set the model. When new file item selected, delete existing model and create new one with new data,
The same as first approach, but instead of recreating model for each data change you can use a single model, but reset its data each time you switch the file.
I'm using Application Express to build a page with a form that shows all the rows in Table A. Table A has to contain all the values from Table B that have a specific "Status".
I'm looking for a way to update Table A so that new rows with the correct status from Table B are added to Table A.
Is there a way to add a button to the page that inserts into Table A those rows? I have no problems with coding the query itself, but on Apex' Page Designer, when I add a button (which I called Refresh) to the page, I can't find a place to add the Insert Query.
Any tips?
there are several ways to do what you need, the simplest one would be to bind a dynamic action to the click event on the button.
On the button definition go to "Action when button clicked" region and on the action field select "Defined by dynamic action"
On execute validations choose "No"
Then, back on the page definition, create a dynamic action, on Event choose "Click", on Selection type choose "Button" this will make a field named button appear whit a list of the available buttons to choose.
In condition you can define a true/false evaluation. if so then you would be able to define actions to execute in both cases, if you leave it empty ("No condition") then all the actions defined will be executed.
Once defined click next and here you decide the action type, the one you need is "Execute PL/SQL Code", which will show a text field on which you can paste your code, and the parameters needed from the page.
finally you can specify if the action will have a repercussion on any kind of visual component on the page, this is for efficiency, but is not necessary.
That would be all, once created, when you click the button the code will be executed on the server.
I often use select lists with my projects but when it comes to a huge select list, I couldn't find a solution. I need a easy, plug and play solution for solution will be used in a few places.
When you have a select box or text box to be filled from a model data, I want to show user a text box, right side of text box, there should be a button to choice the value. Upon clicking that button, popup or a modal will be opened and I filter all the records and find my value, upon clicking value, modal or popup closes and I get choosen value to form control.
İmagine you have a text box to choose your customer, and among 2500 customer,
PS:don't suggest autocomplete, don't want to accomplish it.
Why don't you look at something like Chozen plugin http://harvesthq.github.io/chosen/. It allows you to easily search large select lists