CHAPTER 4

All artifacts we make must be stored somewhere in R. The global environment is home to our artifacts, fiveNumbers, outcome, and lowNumbers. Package functions are all contained within their own package environment.This function takes four arguments: x is the vector to sample from, size is the number of samples to take, replace is what you want to sample with replacement (which means the same numbers can be drawn repeatedly), and prob is used to weight your samples such that some have a better probability of being chosen than others.One of the most common coding errors in R, in our experience, is attempting to execute a function on objects of a given class when R is expecting something else. When it comes to R functions, the str function is one of your best friends; it gives you not only the class but also a look at the values.A vector is a single data row or column. The cells A1:A3 are illuminated, and this group of cells is labeled mixed (see the upper left of the figure). This specific vector contains three components, and it stores data with a character mode.The simplest type of object in R is a vector, and we assume it is the default object type, so it isn't worth mentioning in the environment's grid view. The Type column displays the type of data held within a vector while the object is a vector (its mode). Use the is.vector function and move the name of the object you want to evaluate to it if you want to see if it's a vector.Depending on whether the object is a vector or not, R will return TRUE or FALSE.A matrix is a vector at its center (with dimension attributes). The length function is for vectors, and since matrices are vectors with dimensional attributes, length returns the number of elements in the matrix. Consider a matrix as a vector that "snakes" its way through the rows and columns in a particular direction.