Programming Articles - Page 910 of 3363

To find the minimum for each row based on few columns in an R data frame, we can use pmin function inside with function.For example, if we have a data frame called df that contains five columns say x, y, z, a, and b then minimum for each row based on columns x, y, and b can be found by using the command given below −with(df,pmin(x,y,b))Example 1Following snippet creates a sample data frame −x1

To remove duplicate columns from a matrix in R, we can use unique function.For Example, if we have a matrix called M that contains some duplicate columns then we can use the below command to remove those duplicate columns −unique(M,MARGIN=2)Example 1Following snippet creates a sample matrix −M1

The display of text in base R plot with outline is not possible, for this purpose we would need to use shadowtext function of TeachingDemos package. The shadowtext function will be applied after creating the plot in base R.We will have to provide the location of the text inside the plot and some other arguments such as text that needs to be displayed, color of outline, and size for better display.Example 1Use the following code to display text in base R plot with outline −plot(1) shadowtext(1.2, 1.2, "Point at 1", col="white", cex=2)OutputIf you execute the above given code, it generates ... Read More

For categorical variable, each level is considered as an independent variable and is recognized by factor function. On the other hand, the numerical independent variable is either continuous or discrete in nature.Check out the Example given below for linear regression model summary to understand the difference between categorical and numerical independent variables.ExampleFollowing snippet creates a sample data frame −x

To create an upper triangular matrix using vector elements, we can first create the matrix with appropriate number of columns and rows then take the transpose of that matrix. After that we will assign the lower triangular matrix elements to 0.The selection of number of rows and columns plays an important role here so we need to be careful while choosing them.Check out the examples given below to understand how it can be done.Example 1Following snippet creates a vector −x1

To set values in categorical column to numeric values in R data frame, we can use combine function c.For Example, if we have a data frame called df that contains a categorical column say C which has two categories as Low and High and if we want to represent these categories with 1 and 10 then we can use the below command −df$C

If we create histogram for multiple categories using ggplot2 then the legend is generated automatically based on the categories. And if we want to change that legend or create a histogram with different legend values having different colors for histograms then scale_fill_manual function can be used as shown in the below example.ExampleFollowing snippet creates a sample data frame −Height

Given an integer n that is not negative. The goal is to reverse the bits of n and report the number that results from doing so. While reversing the bits, the actual binary form of the integer is used; no leading 0s are taken into account.Let us see various input output scenarios for thisInput − 13Output − Reverse actual bits of the given number 11(13)10 = (1101)2. After reversing the bits, we get: (1011)2 = (11)10.Explanation − The binary bits are obtained from the input number which is then reversed and finally converted to decimal format which is returned as output.Input − 18Output − ... Read More

To add a caption in a ggplot2 graph in R, we can use labs function. For Example, if we have a data frame called df that contains two columns say X and Y and we want to create scatterplot between X and Y with a caption as a Note that says “Linear Relation Display” then we can use the below command −ggplot(df,aes(X,Y))+geom_point()+labs(caption="Note: Linear Relation Display")ExampleFollowing snippet creates a sample data frame −x

To find the location of installed packages in R in windows operating system, we can use the command mentioned below −.libPaths()This will return the location of installed packages in the first line and the program files in the second line.Use the below mentioned code to find the location of installed packages in windows operating system −.libPaths() OutputIf you execute the given snippet, it generates the following Output −[1] "C:/Users/Nizam/Documents/R/win-library/4.0" [2] "C:/Program Files/R/R-4.0.4/library"Use the below mentioned code to find the location of installed packages in windows operating system −installed.packages()[1:20, ] OutputIf you execute all the above given snippets as a single ... Read More