Using Filter in DB vis - dbvisualizer

A very 'beginner level' doubt but i couldnt find a similiar answer anywhere so i thought lets ask the experts. How do I copy and paste multiple values for comparison in the 'filter' section for a table in DB vis. Take this example
As you can see i need to copy multiple 'rpt_per_id' and use them in the filter section. How do i do that, so that their indentation is good. I know pretty awkward question to ask but still, im not sure how to do this and this would save me some time.

Related

R/exams: Open-ended questions with exams2moodle

My goal is to create a question using R/exams and Moodle including a few plots generated in the Rmd exercise file. The students should describe the plots verbally and then the exercise is graded manually.
Is it possible to use exams2moodle to create such an open-ended free text question for Moodle? There is no extype for it. In the documentation the only hint is:
"In order to generate free text questions in moodle one may specify extra parameters via \exextra. Currently the following options are supported:".
I have tried to add \exextra parameters to the metainformation, but it did not change anything.
A worked example can be found in the essayreg exercise shipped within the package, see: http://www.R-exams.org/templates/essayreg/
And you are right that this is not very well documented. The reason is that we have used somewhat different exextra tags for the Moodle export and for the QTI 2.1 export. We habe to improve and unify that in one of the next R/exams versions.
Also, another pointer, in case this is useful to anyone reading the question: Another useful strategy for asking about the interpretation of (statistical) graphics is in multiple-choice format. Let the participants judge some statements about the graphic that can either be approximately correct or clearly wrong. Of course, with open-ended question you can catch more nuances but with multiple-choice questions you can automatically assess a much larger number of participants. Or participants can self-assess in practice quizzes etc. Examples for this are the boxplots and scatterplot exercises:
http://www.R-exams.org/templates/boxplots/
http://www.R-exams.org/templates/scatterplot/

Dynamic data range references for charts

I have an OpenOffice Calc spread sheet that I'm using to track some data. I have three charts made from the data. I periodically add more data to the spreadsheet. My current way to propagate this to the chart is to alter the data ranges manually of each chart. I'd like to automate this, or at least not have to redundantly change each chart separately.
My current idea was to do something like $A$1:$A{$F$1} for the ranges where $F$1 holds the current last line. Unfortunately, OpenOffice doesn't recognize this, but I thought there might be a function or work around for it. I haven't been able to find one yet.
So, is there a way to execute my idea, or perhaps a better way to do it?
There is a very similar question to this, but the asker asked for many more features and the answer was to use something other than a spreadsheet. It was never answered whether this specific feature was possible.
Also:
First method is to extend the range of the graph way down, with lots of empty space.
Second method is to include only one extra line of data in the graph and when you add data, always insert it above that line.

Can I use Apache Mahout Taste for User Preferences matching?

I am trying to match objects based on predefined user preferences. A simple example would be finding best matching vechicle.
Lets say a user 'Tom' is offered a rented vehicle for travel based on his predefined preferences. In this case, the predefined user preferences will be -
** Pre-defined user preferences for Tom:
PreferredVehicle (Make='ANY', Type='3-wheeler/4-wheeler',
Category='Sedan/Hatchback', AC/Non-AC='AC')
** while the 10 available vehicles are -
Vechile1(Make='Toyota', Type='4-wheeler', Category='Hatchback', AC/Non-AC='AC')
Vechile2(Make='Tata', Type='3-wheeler', Category='Transport', AC/Non-AC='Non-AC')
Vechile3(Make='Honda', Type='4-wheeler', Category='Sedan', AC/Non-AC='AC')
;
;
and so on upto 'Vehicle10'
All I want to do is - choose a vehicle for Tom that best matches his preferences and also probably give him choices in order, i.e. best match first.
Questions I have :
Can this be done with Mahout Taste?
If yes, can someone please point me to some example code where I can start quickly?
A recommender may not be the best tool for the job here, for a few reasons. First, I don't expect that the best answers are all that personal in this domain. If I wanted a Ford Focus, the best alternative you have is likely about the same for most every user. Second, there is not much of a discovery problem here. I'm searching for a vehicle that meets certain needs; I don't particularly want or need to find new and unknown vehicles, like I would for music. Finally you don't have much data per user; I assume most users have never rented before, and very few have even 3+ rentals.
Can you throw this data at a recommender anyway? Sure, try Mahout Taste (I'm the author). If you have the book Mahout in Action it will walk you through it. Since it's non-rating data, I can also recommend the successor project, Myrrix (http://myrrix.com) as it will be easier to set up and run. You can at least evaluate the results to see if it's anywhere near useful.
Either way, your work will just be to make a CSV file of "userID,vehicleID" pairs from your data and feed it in. Then it will give you vehicle IDs as recommendations for any user ID.
But, I imagine you will do much better to analyze what people picked when the car wasn't available, and look at the difference, and learn which attributes they are most and least likely to be sacrificed, and learn to score the alternatives that way. This is entirely feasible since this data set is small, and because you have rich item attribute data.

Multiple Models

I like knockoutjs, the sooner we get rid of coding directly toward the DOM the better. I'm having trouble understanding how I would do something which I'm going to explain in terms of a question/answer site. (This is probably a general MVC/MVVM question)
In my data model I have a question[id, description] and answer[id, question_id, text]. The browser requests a list of questions which is bound to a tbody, one column will display the question description, while the other should be bound to an answer textbox.
One obvious way of doing this is to have a QuestionAnswer[question_id, answer_id, question_descrition, answer_text] model. Ideally I'd like to keep them separate to minimize transformation when sending/receiving/storing, if there isn't some way of keeping them separate then I have the following question:
Where is the ideal place to create the QuestionAnswer model ? My bet is that by convention its created on the server.
If there is such an example somewhere please point me to it, otherwise I think it would make a good example.
Please help me wrap my head around this, Thanks!
What you could do is to create the combined model on the server, serialize it to json and then use the mapping plugin to add the serialized list to the view model.
I'm doing that here only it isn't a combined model, but shouldn't make any difference. Especially since it seems like your relation is one-to-one.
If you need to create an "object" in your view model, you can use the mapping definition to do so, like I do here.
I use C# to build my model on the server, but I guess you can use whatever you are comfortable with.
The cool thing with the mapping plugin is that it adds the data to the view model so that you can focus on behaviour.
Ok,
I'v gathered my thoughts on what my question is actually asking.
To do data binding on the client side you obviously need your data model there as well. I was conflicted on what I needed to send over and at what time.
To continue with the Question/Answer site idea: Sending down a list of answers each of which have a question in them is what should be done. That way you can bind to the answer list and simply bind the question description of each answer to the first table column.
If later I want to make a question editor I would potentially send a complete different data structure down and not reuse the Answer has a Question structure previously used.
I thought there might be a way of sending down a more complex data structure that references itself. Which apparently is possible in JSon with some extra libraries.

How can I index a bunch of files in Perl?

I'm trying to clean up a database by first finding unreferenced objects. I have extracted all the database objects into a list, and all the ddl code into files, I also have all the Java source code for the project.
Basically what I want to do (preferably in Perl as it's the scripting language that I'm most familiar with) is to somehow index the contents of all the extracted database ddl and Java files (to speed up the search), step through the database object list and then search through all the files (using the index) to see if those objects are referenced anywhere and create a report.
If you could point me in the right direction to find something that indexes all those files in a way that I can search them (preferably in Perl) I would greatly appreciate it.
The key here is to be able to do this programatically, not manually (using something like Google desktop search).
Break the task down into its steps and start at the beginning. First, what does a record look like, and what information in it connects it to another record? Parse that record, store its unique identifier and a list of the things it references.
Once you have that list, invert it. For each reference, create a list of the objects referenced. Count them by their identifier. You should be able to get the ones whose count is zero.
That's a very general answer, but you asked a very general question. If you are having trouble, break it down into just one of those steps and ask a more specific question, supplying sample data and the code you've tried so far.
Good luck,
An interesting module you might use to do what you want is KinoSearch, it provides you the kind of indexing you said to be looking for. Then you can go through the object identifiers and check if there are references to it.