Python is among the most popular programming language for data science nowadays, and getting started with Python is quite easy. You can just install e.g. a free platform like Anaconda, then you can get direct access to Python as well as most of its preinstalled modules (Numpy, pandas, matplotlib, etc.), its IDE (Spyder, etc) and its easygoing package management tools.
Categorical variables, including nominal and ordinal variables in R programming language are called factor variables. For example, gender(male/female) is nominal, and survey results (excellent, good, normal, bad) have ordinal values. Categorical variables are useful because many data analysis operations are related to values in different categories, such as contingency tables between two categorical variables for independence analysis, hypothesis testing of homogeneity of variances, just name a few.
When R software and RStudio program have been installed on your computer, R working session can be simply started by clicking the RStudio app from your Windows start menu.
list is a type of data structure in R programming language. Unlike other data structures, especially matrix and vector, in which each element must has the same type of data, a list provides the flexibility of storing various information in one object.
Violin plot is quite similar as boxplot, in the sense that it shows the range of the data. And at the same time a violin plot illustrates the data distribution shape with a density curve on both sides of the central pillar.
When we perform data analysis using Python, it is often useful to pass a list in calling the function as we want each element of the list to be accessed by the function.
A Student t-distributed random variable is modeling the ratio between a standard Normal random variate and square root of a Chi-squared random variable divided by its degrees of freedom.
Kernel density function is a nonparametric method to find the drawing density curve of random samples, and it is often used to draw a smoothed curve in data visualization. In R programming with ggplot2 package, a chaining of functions ggplot() and geom_density() is often used to draw different smoothed curves showing the distribution of continuous variables.
A function in Python is a group of code statements wrapped together to perform specific tasks. After a function is defined, then it can be called by passing real values to its arguments and get the returning results. A while loop in Python is a group of conditional statements bundled in a statement beginning with keyword ‘while’, and the codes will run forever until the condition returns false. By including a user-defined function inside a while loop in Python, many iterative tasks can be fulfilled.
Poisson distribution is a discrete distribution. It is frequently used to model the counts of event occurrence during a specified time interval, such as telephone calls coming in to a call center in a given day. There is one parameter in the Poisson probability function, λ, which denotes the constant occurring rate in a Poisson process.