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Articles by Nizamuddin Siddiqui
Page 70 of 196
How to plot values with log scales on x and y axis or on a single axis in R?
We can plot numerical values in R with many scales and that includes log scale as well. Also, it is possible to plot the values with log scales on both the axes. In base R, the best way to do this is defining the axes values with decimal representation as shown in the below examples with well-defined log.Consider the below vector −Exampleset.seed(555) x
Read MoreHow to repeat a column of a data frame and join it with another data frame in R by rows?
Suppose we have a data frame df1 that contains 5 columns and another data frame df2 that contains only column but the data type of the columns in both the data frames is same. Now we might want to add the column of the second data frame starting at the end of the rows of the first data frame by creating the same number of columns as in first data frame. This might be required by researchers to understand the impact of an external variable on the result of the analysis and it can be done with the help of ...
Read MoreHow to find the position of one or more values in a vector into another vector that contains same values in R?
Finding the position of one of more values that are common in two vectors can be easily done with the help of match function. The match function will match the values in first and second vector then return the index or position of these common values in second vector.Exampleset.seed(145) x1
Read MoreHow to extract odds ratio of intercept and slope coefficient from simple logistic model in R?
To create the simple logistic model, we need to use glm function with family = binomial because the dependent variable in simple logistic model or binomial logistic model has two categories, if there are more than two categories then the model is called as multinomial logistic model. If we want to extract the odds ratio of slope and intercept from the simple logistic model then exp function needs to be used with model object as shown in the below examples.Exampleset.seed(999) x1
Read MoreHow to change column names to capital letters from lower case or vice versa in R?
Mostly, we get data that contain column names in lowercase or just first letter is in upper case. If we want to convert those column names to all capital letter words or uppercase then toupper function can be used to the names of the columns. This can be done by using the below syntax −Syntaxnames(“data_frame_name”)
Read MoreHow to find the rank of a vector elements in R from largest to smallest?
To find the rank of a vector of elements we can use rank function directly but this will result in ranks from smallest to largest. For example, if we have a vector x that contains values 1, 2, 3 in this sequence then the rank function will return 1 2 3. But if we want to get ranks from largest to smallest then it would be 3 2 1 and it can be done in R as rank(-x).Examplex1
Read MoreHow to check whether a string is in lowercase or uppercase in R?
We can use str_detect function to check whether a single string or a vector of strings is in lowercase or uppercase. Along with str_detect function, we need to use either upper or lower to check whether the string is in lowercase or uppercase and the output will be returned in TRUE or FALSE form, if the string will be in lowercase and we pass lower with str_detect function then the output will be TRUE and vice-versa.Examplex1
Read MoreHow to find the variance of row elements of a matrix in R?
Finding the variance of columns is a common task in data analysis but often data is provided in wide format instead of long format, therefore, the cases are represented vertically and the variables are aligned horizontally and this data could be available in matrix or any other form. Therefore, the variance can be easily found by using apply function.ExampleM1
Read MoreHow to represent all values of X-axis or Y-axis on the graph in R using ggplot2 package?
If we have many unique elements or repeated in a column of an R data frame and create a graph using that column, either on X-axis or Y-axis then R automatically choses the axes labels, this might not display all the unique values of the column in the plot. Therefore, we can use scale_x_continuous function or scale_y_continuous function with labels depending on our requirement to display the column values.Consider the below data frame −Examplex
Read MoreHow to remove underscore from column names of an R data frame?
When we import data from outside sources then the header or column names might be imported with underscore separated values and this is also possible if the original data has the same format. Therefore, to make the headers shorter and look better we would prefer to remove the underscore sign and this can be easily done with the help of gsub function.Consider the below data frame −Examplex_1
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