subset
R - Select rows for random sample of column values?
How can I select all of the rows for a random sample of column values? I have a dataframe that looks like this:[详细]
2023-03-04 07:22 分类:问答Using multiple criteria in subset function and logical operators
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[详细]
2023-03-01 01:13 分类:问答Subset a data frame based on column entry (or rank)
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[详细]
2023-02-28 21:10 分类:问答Find all possible subset combos in an array?
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?[详细]
2023-02-28 14:32 分类:问答Rails find a specific entry in a scoped table
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\")[详细]
2023-02-27 11:32 分类:问答SQL: How To Select Earliest Row
I have a report that looks something like this: CompanyAWorkflow27June5 CompanyAWorkflow27June8 CompanyAWorkflow27June12[详细]
2023-02-27 05:04 分类:问答How can I get the intersection, union, and subset of arrays in Ruby?
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.[详细]
2023-02-26 02:14 分类:问答Entity Framework: subset entity of larger entity
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[详细]
2023-02-22 19:30 分类:问答Concatenate expressions to subset a dataframe
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[详细]
2023-02-21 23:18 分类:问答prolog: subsets of length k
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).[详细]
2023-02-21 15:35 分类:问答