Insightful Analytics
Standard Error (SE) measures the variability or dispersion of the sample mean estimate of a population mean. Here are three ways to calculate standard error in R: Using sd() with length() Using the standard error formula Using std.error() from plotrix package Here is the basic formula: where: σ = sample standard deviation n = sample … Read more
The pnorm() function in R calculates the cumulative density function (cdf) value of the normal distribution given a specific random variable q, the population mean μ, and the population standard deviation σ. It returns the probability that a normally distributed random variable is less than or equal to a given value. It provides the probability … Read more
Set the current working directory The setwd() function sets the working directory to the new location, allowing us to change the default location for file operations. The working directory is a location where R looks for files to read or save by default. Use absolute paths for reliability, relative paths for flexibility. Syntax setwd(dir) Parameters … Read more
The sd() function in R calculates the sample standard deviation of a numeric vector or an object, excluding factors. It uses Bessel’s correction (n-1). The standard deviation is a measure that tells you how spread out the data is in a dataset. It is a measurement of the dispersion of the values. If the standard … Read more
The dnorm() function in R calculates the value of the probability density function (pdf) of the normal distribution of a given value or vector of values. It determines the probability density of a continuous random variable following a normal distribution, characterized by a mean (μ) and standard deviation (σ). How do you define the normal … Read more
The rnorm() method in R generates random numbers from a normal (Gaussian) distribution, which is characterized by a bell-shaped curve defined by its mean and standard deviation, which are widely used in statistical simulations and data analysis. To understand in simple terms, let me take an example. Let’s say I want to select some candies. … Read more
R cbind() (column bind) is a function that combines specified vectors, matrices, or data frames by columns, creating a new matrix or data frame where the input objects are placed side by side. Syntax cbind(…, deparse.level = 1) Parameters Argument Description … It represents the objects that we need to combine column-wise. It can be … Read more
The rbind() function combines R objects, such as vectors, matrices, or data frames, by rows. It stacks rows vertically. The above figure illustrates how the rbind() method works on data frames, combining their rows. The data frame that is being stacked must have the same number of columns (or elements, in the case of vectors), … Read more
To format dates in R, use the format() function with various specifications. Having your dates in the proper format allows you to know that they are dates and which calculations should be performed on them. Date formats Conversion specification Description Example %a Abbreviated weekday Sun, Mon %A Full weekday Sunday, Monday %b or %h Abbreviated month Sep, Nov %B Full month September, … Read more
When working with R in an interactive mode, you don’t need to use any functions or methods to print the result of your expressions; it will print them automatically. Simply typing a variable or expression will print its value. data <- 42 data # [1] 42 However, you need functions to see the output if … Read more
