Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
Articles by Nizamuddin Siddiqui
Page 103 of 196
How to add a row in an R data frame at a specific place?
The data collected for the first time is utilised as it is but when we need to go for secondary data to conduct the same or similar study again, we can use new data as well as the primary data. In this type of situations, we might want to randomly organize data rows that includes new and old data. Also, there is a possibility of missing data row which is found at later stage in the study then it can be also added. Hence, a row might be required to added in the existing data frame. This can be done ...
Read MoreHow to create three-dimensional arrays of different sizes in R?
A three-dimensional array can have matrices of different size and they are not necessarily to be square or rectangular. Also, all the elements in an array are of same data type. To create a three-dimensional array of different size we would need to use the proper number of rows and columns within the array function.Example Live DemoA1
Read MoreHow to find percentile rank for groups in an R data frame?
The word percentile means the percentage that falls below or above the percentile value. For example, if we have a value that lies at 50th percentile then we would say 50 percent of the values lies below or above that value. The value 50 here is called the percentile rank. To find the percentile rank for groups in an R data frame, we can use mutate function of dplyr package.ExampleConsider the below data frame − Live DemoGroup
Read MoreHow to combine vectors of equal length into a list with corresponding elements representing a single element of the list in R?
To combine three vectors into a list with corresponding elements representing a single element of the list we can use mapply function. For example, if we have three vectors x, y, and z each having number of elements equal to one-hundred then the list with corresponding elements can be created by using mapply(c,x,y,z,SIMPLIFY=FALSE).Example Live Demox1
Read MoreHow to perform tukey HSD in base R?
First thing you must remember while moving on to post hoc analysis is the null hypothesis of the analysis of variance must be rejected, so that we can claim there exists a difference in the group means. Now, once we achieve that the tukey HSD can be performed simply by using TukeyHSD function in base R.ExampleConsider the below data frame − Live Demox1
Read MoreWhat is the shortest way to round to the integer value in R?
The shortest way to round to the integer value is using trunc function. The trunc function is used to return the largest integer that is smaller than or equal to the actual value, that means it rounds downs to the nearest integer. It works as a ceiling function for negative number and floor function for positive number.Example Live Demox1
Read MoreHow to create a plot of quadratic regression with fitted values against X in base R?
The quadratic regression model can be plotted by using the plot function but we would need to find the fitted values using the model and this can be done with the help of fitted function. For example, if we have a quadratic model M and the data has an independent variable x then the model against x can be created by using plot(x,fitted(M)).Example Live Demox1
Read MoreHow to create a plot in base R with dates sequence on X-axis?
If we have a vector that contains dates as sequence that needs to be plotted on the X-axis and another vector for the response then the plot can be simply created by using the plot function. In the plot function, we would need to pass the dates as the first argument and the response vector as the second argument. Check ou the examples below to understand how it works.Example Live Demox
Read MoreHow to create a plot with dashed regression line in base R?
To create a regression line in base R, we use abline function after creating the scatterplot but if we want to have the line dash format then lty argument must also be used with value equals to 2 after defining the regression model inside abline. For example, if we have two columns x and y stored in a data frame called df then the plot with dashed regression line can be created by using −plot(y~x, data=df) abline(lm(df$y~df$x), lty=2)ExampleConsider the below data frame − Live Demo> x y df dfOutput x y 1 5.243553 4.969598 2 4.681088 ...
Read MoreHow to create a plot with reversed Y-axis labels in base R?
To create a plot with reversed Y-axis we need to use the rev function for the Y-axis labels with ylim but we would also need to define the range for the y-axis values, otherwise, R will throw an error. For example, if we have two vectors named as x and y then the plot with reversed Y-axis labels can be created by using plot(x,ylim=rev(range(y))).Example Live Demox
Read More