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How to create, index and modify data frames in R

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! Data frame is the most widely used data object in R programming, due to the fact that a data frame can store different type of data contents (numeric, character, etc) into a tabular form. Creating a data frame is more than just simple. You can concretely combine several vectors into a data frame, as Read more…

By wilsonzhang746, ago

Some useful functions for working with objects in R

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! In this post, we will introduce and provide several useful and important functions in R. Most of them are fairly basic, and frequently used in data analysis with R programming. length() – get the length of an object dim() – to show the dimension of an object str() – to show structure of a Read more…

By wilsonzhang746, ago

Using with() function to simplify your work in R

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! with() function in R provides an alternative and often easier way to deal with data management and analysis. Say we have a data frame ‘grade’, and want to calculate the summary statistics of variable ‘Math’ and correlation between variables ‘Math’ and ‘Physics’. In the normal way, we can write the code as follows: If Read more…

By wilsonzhang746, ago

Variable type and conversion in R

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! In R programming, variable type can be numeric or character. Categorical variables are usually called factors. R provides a series of functions working with specific type test and type conversion. In the following code example, a data frame is loaded from a csv file, then specific variables are check if they are numeric or Read more…

By wilsonzhang746, ago

Calculate mean, median and mode using Python

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! Mean, median and mode are three statistics that measure the central tendency of numerical data. Mean is the average of sample, and median the mid point of the sample with value sorting from the lowest to the highest, and mode is the value that occur most frequently in the sample. In Python there are Read more…

By wilsonzhang746, ago

Environment system in R programming

We provide effective and economically affordable training courses for R and Python, click here for more details and course registration ! R’s environment system behaves as a hierarchical folder system where objects in an R session are located. So when a R session is started, and with several objects created, the environment hierarchy in R session can be shown with function parenvs(). For exmple, in the following code, we create several objects, and then create Read more…

By wilsonzhang746, ago

Sorting a list in Python

We provide effective and economically affordable training courses for R and Python, Click here for more details and course registration ! When a list is created in Python, the order of its element contained can be sorted in alphabetical order later. There are mainly two functions for sorting a list in Python. sort() function will sort a list’s elements permanently. If you just want to sort a list temporarily, you can use sorted() function. The Read more…

By wilsonzhang746, ago

Combination of a box plot and a violin plot using ggplot2 in R

We provide effective and economically affordable training courses for R and Python, Click here for more details and course registration ! A Box plot shows descriptive statistics of a continuous with a box and whispers. Five statistics of the variable, namely, the minimum and the maximum, the median, and the lower quantile and upper quantile are depicted in the plot. A violin plot shows a smoothed nonparametric violin curve of a continuous variable. Combination of Read more…

By wilsonzhang746, ago

Plot histograms using ggplot2 in R

We provide effective and economically affordable training courses for R and Python, Click here for more details and course registration ! Histogram is a type of graph that shows the distribution of a continuous variable. The range of value of the variable is divided into parts (range), then the frequency for each bin is plotted. In R, with ggplot2 package, function geom_histogram() can be used to plot histograms. Histogram can be a simple graph using Read more…

By wilsonzhang746, ago

Plot Barchart with ggplot2 in R

We provide effective and economically affordable training courses for R and Python, Click here for more details and course registration ! Barcharts can be used to plot the frequency of a single categorical variable, or illustrate the cross relationship between two or more categorical variables. In R programming, function geom_bar() from ggplot2 package can easily create simple barcharts, stacked or grouped barcharts. The following codes show creation of different barcharts, using a virtual dataset “grade”. Read more…

By wilsonzhang746, ago