How can I select all of the rows for a random sample of column values? I have a dataframe that looks like this:
If I want to select a subset of data in R, I can use the subset f开发者_如何学JAVAunction. I wanted to base an analysis on data that that was matching one of a few criteria, e.g. that a certain variab
I have a data.frame as simple as this one: id group iduvalue 111_134 212_123 313_167 424_26 525_224 626_245 131_334
I ne开发者_运维知识库ed to get all possible subsets of an array with a minimum of 2 items and an unknown maximum. Anyone that can help me out a bit?
New to rails....still trying to grasp all the \"methods\" Table is called Histories. @compa = History.scoped(:limit => 10,:conditions => {:name => \"IBM\"}, :order => \"closedate ASC\")
I have a report that looks something like this: CompanyAWorkflow27June5 CompanyAWorkflow27June8 CompanyAWorkflow27June12
I want to create different methods for a class called Mul开发者_如何学Gotiset. I have all the required methods, but I\'m unsure of how to write intersection, union, and subset methods.
Sooo basically I have a table called Comment. On that table I have three fields, ID Title Text I\'ve created an Entity object for the table already and it maps all three fields, but what I want no
I am attempting to create a function that will calculate the mean of a column in a subsetted dataframe. The trick here is that I always to want to have a couple subsetting conditions and then have the
in class we went over the subset_of/2 predicate that my teacher gave as follows: subset_of([],[]). subset_of([X|Xs],Zs):-subset_of(Xs,Ys),maybe_add(X,Ys,Zs).
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