assign

问题 Say you have an array like this... username, password, email and you need to assign a value to each element. After, this needs to be formatted into a string like this: username=someRandomValueAssigned&password=someRandomValueAssigned&email=someRandomValueAssigned how would I do this? Thanks. 回答1: $keys = array('username', 'password', 'email'); $values = array('someusername', 'somepassword', 'someemail'); $data = array_combine($keys, $values); array_combine will return an associative array

问题 I need to create a data frame from a function entering another data frame name and reshaping the data. The issue comes when I need to named the output after a transformation of the input table name. My code so far is: tablaXYZ<-data.frame(a=seq(1,2,1), 'X1'=seq(2,3,1), 'X2'=seq(3,4,1)) rownames(tablaXYZ)<-c('X1', 'X2') And the function I worte is: creaMelts<-function(tbl){ library(reshape2) texto<-deparse(substitute(tbl)) tbl2<-melt(tbl, id.vars=rownames(tbl)) texto2<-substr(texto,4,nchar

问题 Is there any way to return the value of an entire row of a multidimensional array to a one dimensional array In VBA? Something like, arr_1dim = arr_2dim(3,:) is a matlab expression for assigning the row 3 of arr_2dim array to arr_1dim in one single stretch. Is there any similar less expensive method in Excel VBA? 回答1: No there is no VBA-function to get a row or column. You can only write it yourself, or take a look here: http://www.cpearson.com/excel/vbaarrays.htm 回答2: There is a simple way

问题 I am using a R package, in which there are 2 functions f1 and f2 (with f2 calling f1) I wish to overwrite function f1. Since R 2.15 and the mandatory usage of namespace in packages, if I just source the new function, it is indeed available in the global environement (ie. just calling f1(x) in the console returns the new result). However, calling f2 will still use the packaged function f1. (Because the namespace modifies the search path, and seals it as explained here in the Writing R

问题 I have a data frame, 'mydata': head(mydata) ID MDC 000001 21A 000002 5 000003 8 ... I've split my data frame by one of it's column values, namely 'MDC'. This created a list, subdivided into further lists by the column value 'MDC': mylist <- split(mydata, mydata$MDC, drop=TRUE) summary(mylist) Length Class Mode 0 75 data.frame list 1 75 data.frame list 10 75 data.frame list 11 75 data.frame list 12 75 data.frame list 21A 75 data.frame list ... I now want to create a data frame for each MDC

问题 Is there a way to assign a value to a specific column within a data frame? e.g., dat2 = data.frame(c1 = 101:149, VAR1 = 151:200) j = "dat2[,"VAR1"]" ## or, j = "dat2[,2]" assign(j,1:50) The approach above doesn't work. Neither does this: j = "dat2" assign(get(j)[,"VAR1"],1:50) 回答1: lets assume that we have a valid data.frame with 50 rows in each dat2 <- data.frame(c1 = 1:50, VAR1 = 51:100) 1 . Don't use assign and get if you can avoid it. "dat2[,"VAR1"]" is not valid in R . You can also note

问题 Update 2 @G. Grothendieck posted two approaches. The second one is changing the function environment inside a function. This solves my problem of too many coding replicates. I am not sure if this is a good method to pass through the CRAN check when making my scripts into a package. I will update again when I have some conclusions. Update I am trying to pass a lot of input argument variables to f2 and do not want to index every variable inside the function as env$c, env$d, env$calls , that is

问题 This has been bugging me for a while. struct person { char name[15]; int age; }; struct person me; me.name = "nikol"; when I compile I get this error: error: incompatible types when assigning to type ‘char[15]’ from type ‘char *’ am I missing something obvious here? 回答1: Arrays are second-class citizens in C, they do not support assignment. char x[] = "This is initialization, not assignment, thus ok."; This does not work: x = "Compilation-error here, tried to assign to an array."; Use library

问题 Still trying to get into the R logic... what is the "best" way to unpack (on LHS) the results from a function returning multiple values? I can't do this apparently: R> functionReturningTwoValues <- function() { return(c(1, 2)) } R> functionReturningTwoValues() [1] 1 2 R> a, b <- functionReturningTwoValues() Error: unexpected ',' in "a," R> c(a, b) <- functionReturningTwoValues() Error in c(a, b) <- functionReturningTwoValues() : object 'a' not found must I really do the following? R> r <-

问题 I'm doing an assignment where I have to randomly place players on a field with random coordinates, but those coordinates must be unique or else they must be regenerated. I'm trying to randomize integers and assign them to struct members. However, what I'm doing right now doesn't seem to work properly according to my professor. This is the struct: struct player { int x; int y; int direction; int id; int presence; }; Those are my two arrays, one for the field and one for the size of the team on