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
-
Economics & Finance
Articles by Nizamuddin Siddiqui
Page 129 of 196
How to find the ID wise frequency in an R data frame?
To find the ID wise frequency in an R data frame, we can use summarise function of dplyr package after defining the ID with group_by function, also the column for which we want to find the frequency will be placed inside group_by function.Check out the below examples to understand how it can be done.Example 1Following snippet creates a sample data frame −ID
Read MoreFind the standard deviation for every n number of observations in an R data frame column.
To find the standard deviation for every n number of observations in an R data frame, we can use rollapply function of zoo package.For Example, if we have a data frame called df that contains a column say X containing 100 values then we can create a column with standard deviation of every 10 values by using the below command −df$SD_10
Read MoreHow to find the mean of all columns by group in R?
To find the mean of all columns by group, we can use summarise_all function along with mean function after defining the groups with group_by. For example, if we have a data frame called df that contains a grouping column say G and some numerical columns then we can find the mean of all columns by values in grouping column by using the below given command −df%>%group_by(G)%>%summarise_all("mean")Example 1Following snippet creates a sample data frame −Grp
Read MoreHow to find the mean of every n values in an R vector?
To find the mean of every n values in an R vector, we would first need to convert the vector into matrix with number of rows based for n values then we can use colMeans function.For example, if we have a vector called X that contains hundred values then we can find the mean of every ten value by using the command given below −colMeans(matrix(X,10))Example 1To find the mean of every n values in an R vector, use the command given below −x1
Read MoreHow to find the most frequent factor value in an R data frame column?
To find the most frequent factor value in an R data frame column, we can use names function with which.max function after creating the table for the particular column. This might be required while doing factorial analysis and we want to know which factor occurs the most.Check out the below examples to understand how it can be done.Example 1Following snippet creates a sample data frame −Factor_1
Read MoreHow to extract the first row of each matrix stored in a list in R?
To extract the first row of each matrix stored in a list in R, we can use lapply function. For example, if we have a list called LIST that contains some matrices then we can find the first row of each matrix by using the command given below − lapply(LIST,'[',1,)Check out the below given example to understand how it can be done.ExampleFollowing snippet creates a list of matrices −M1
Read MoreHow to extract the outliers of a boxplot in R?
To extract the outliers of a boxplot, we can use out function along with the boxplot function. For example, if we have a vector called X which contains some outliers then we can extract those outliers by using the command given below − boxplot(df$X, plot=FALSE)$outThis command will not create a plot as plot is set to FALSE.ExampleFollowing snippet creates a sample data frame −df=data.frame(x=rlnorm(25)) dfThe following dataframe is created − x 1 0.5699270 2 3.5812629 3 0.3507882 4 0.1400328 5 0.7239948 6 2.5494114 7 3.1243611 8 5.3207739 9 0.1672539 10 7.6235529 11 0.4950263 12 1.1713592 13 1.6590328 14 ...
Read MoreHow to replace zero with previous value in an R data frame column?
To replace zero with previous value in an R data frame column, we can use na.locf function of zoo package but to apply this we first need to replace the zero values with NA.For example, if we have a data frame called df that contains a column say Rate then we can use the below commands to replace 0 values in Rate with previous value by using the below given commands − df$Rate[df$Rate==0]
Read MoreCreate scatterplot for two dependent variables and one independent variable in R.
To create scatterplot for two dependent variables and one independent variable, we can use geom_point function and geom_smooth function of ggplot2 package. Both of these functions will be used twice, where we can define the aesthetics of the plot for each dependent variable as shown in the Example below.ExampleFollowing snippet creates a sample data frame −x
Read MoreCreate line chart for mean covered with minimum and maximum in R.
To create line chart for mean covered with minimum and maximum in R, we first need to create columns for row means, row minimum, and row maximum after that geom_line function can be used along with geom_ribbon function of ggplot2 package as shown in the below example.ExampleFollowing snippet creates a sample dataframe.x
Read More