assign

问题 I'm trying to use "assign" function, inside a for loop, to assign the value of a file to one variable. When I call the function, it brings the correct answer but in the end it gives me the following warning messages: In assign(fileList, read.csv(fileList[i])) : only the first element is used as variable name If I run > corr("specdata", 129) I can see the correct answer, it can print all the right values, but If I assign the values to any variable for example, it says that this variable is

问题 I'm trying to use "assign" function, inside a for loop, to assign the value of a file to one variable. When I call the function, it brings the correct answer but in the end it gives me the following warning messages: In assign(fileList, read.csv(fileList[i])) : only the first element is used as variable name If I run > corr("specdata", 129) I can see the correct answer, it can print all the right values, but If I assign the values to any variable for example, it says that this variable is

问题 Earlier today I asked for help for building a database in prolog and how to search by parameters, and somebody came up with this: You can also add a list of terms to every processor, like: processor(pentium_g4400, [brand('intel'), family('pentium'), series('g4400'), clock(3.3), socket('lga1151'), ram('ddr4'), cores(2), threads(2)]). In that case you can query with: processor(Proc, Specs), member(family('pentium'), Specs). And it worked pretty well, but, the command "member" does not seem to

问题 Given var maybeInt: Int? how to the following two conditional statements differ? // (1) if let y = maybeInt { y } else { println("Nope") } // (2) if let y = maybeInt? { y } else { println("Nope") } They seem to behave exactly the same. Is the former a short-cut for the latter? 回答1: The second syntax is optional chaining — just with nothing after the chaining operator. It accesses whatever optional comes before it (if the optional is not nil ), allows chaining property accesses or method calls

问题 I am trying to rename a variable over several data frames, but assign wont work. Here is the code I am trying assign(colnames(eval(as.name(DataFrameX)))[[3]], "<- NewName") # The idea is, go through every dataset, and change the name of column 3 to # "NewName" in all of them This won't return any error (All other versions I could think of returned some kind of error), but it doesn't change the variable name either. I am using a loop to create several data frames and different variables within

问题 Yesterday I gave this answer: Matching Data Tables by five columns to change a value in another column. In the comments, the OP asked if we could effectively achieve a left join of the two tables and thereby get the NAs that would result in the right table to be assigned to the left table. It seems to me that data.table does not provide any means of doing this. Here's the example case I used in that question: set.seed(1L); dt1 <- data.table(id=1:12,expand.grid(V1=1:3,V2=1:4),blah1=rnorm(12L))

问题 There seems to be a minor difference between data.tabel's assignment by reference := in the standard to the functinal form. Standard form coerces RHS to vector, the functional form does not. A detail, but not documented as I believe. library(data.table) dt <- data.table(a = c('a','b','c')) v <- c('A','B','C') l <- list(v) all.equal(copy(dt)[, new := v], copy(dt)[, `:=` (new = v)]) # [1] TRUE all.equal(copy(dt)[, new := l], copy(dt)[, `:=` (new = l)]) # [1] "Datasets have different column

问题 There seems to be a minor difference between data.tabel's assignment by reference := in the standard to the functinal form. Standard form coerces RHS to vector, the functional form does not. A detail, but not documented as I believe. library(data.table) dt <- data.table(a = c('a','b','c')) v <- c('A','B','C') l <- list(v) all.equal(copy(dt)[, new := v], copy(dt)[, `:=` (new = v)]) # [1] TRUE all.equal(copy(dt)[, new := l], copy(dt)[, `:=` (new = l)]) # [1] "Datasets have different column

问题 I'm trying to use assign values in an object in a list. What I want to do is change some elements. For example: x <- list() x$test <- 1 assign("x$test", 2) x$test == 1 [1] TRUE Any thoughts? I need to use assign because I am building a function which will take the names of the objects within the list (x) as inputs. 回答1: Looks like you're out of luck. From the help file: ‘assign’ does not dispatch assignment methods, so it cannot be used to set elements of vectors, names, attributes, etc. Note

问题 Is it possible to call a javascript function after loading a page with window.location.assign? I have this code. <script language="javascript" type="text/javascript"> function Loadspirit(){ window.location.assign("spirituality.php"); ReadEnglish(); } </script> I load the page then call ReadEnglish(), a function defined in spirituality.php. The function doesn't execute. What would be the way to make the function execute? 回答1: As soon as you assign a new window.location, the browser starts