I’m trying to learn R and I can’t figure out how to append to a list. If this were Python I would . . . #Python vector = [] values = [‘a’,’b’,’c’,’d’,’e’,’f’,’g’] for i in range(0,len(values)): vector.append(values[i]) How do you do this in R? #R Programming > vector = c() > values = c(‘a’,’b’,’c’,’d’,’e’,’f’,’g’) > … Read more
Is there a built-in vector function in C++ to reverse a vector in place? Or do you just have to do it manually? 7 Answers 7
Can anyone tell me how to find the common elements from multiple vectors? a <- c(1,3,5,7,9) b <- c(3,6,8,9,10) c <- c(2,3,4,5,7,9) I want to get the common elements from the above vectors (ex: 3 and 9) 3 Answers 3
Are all of the following statements true? vector<Type> vect; //allocates vect on stack and each of the Type (using std::allocator) also will be on the stack vector<Type> *vect = new vector<Type>; //allocates vect on heap and each of the Type will be allocated on stack vector<Type*> vect; //vect will be on stack and Type* will … Read more
I have a dataframe such as: a1 = c(1, 2, 3, 4, 5) a2 = c(6, 7, 8, 9, 10) a3 = c(11, 12, 13, 14, 15) aframe = data.frame(a1, a2, a3) I tried the following to convert one of the columns to a vector, but it doesn’t work: avector <- as.vector(aframe[‘a2’]) class(avector) [1] “data.frame” … Read more
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers. This question does not appear to be about programming within the scope defined in the help center. Closed 5 months ago. The community reviewed whether to reopen this question 5 months ago and left it closed: Original close reason(s) were … Read more
What is the cheapest way to initialize a std::vector from a C-style array? Example: In the following class, I have a vector, but due to outside restrictions, the data will be passed in as C-style array: class Foo { std::vector<double> w_; public: void set_data(double* w, int len){ // how to cheaply initialize the std::vector? } … Read more
This question already has answers here: What is the easiest way to initialize a std::vector with hardcoded elements? (29 answers) Closed 2 years ago. I want to initialize a vector like we do in case of an array. Example int vv[2] = {12, 43}; But when I do it like this, vector<int> v(2) = {34, … Read more
It seems that Vector was late to the Scala collections party, and all the influential blog posts had already left. In Java ArrayList is the default collection – I might use LinkedList but only when I’ve thought through an algorithm and care enough to optimise. In Scala should I be using Vector as my default … Read more
Ok, this is really difficult to confess, but I do have a strong temptation at the moment to inherit from std::vector. I need about 10 customized algorithms for vector and I want them to be directly members of the vector. But naturally I want also to have the rest of std::vector‘s interface. Well, my first … Read more
