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Articles by Nizamuddin Siddiqui
Page 134 of 196
How to calculate two period moving average for vector elements in R?
If we want to find the two−period moving average easily then it cannot be done in base R. We need to use rollmean function of zoo package that solves this problem in a single line of code. For example, if we have a vector x that contains hundred from starting from 1 to 100 then the two−period moving for x can be found by using rollmean(x,2)Loading zoo package −library(zoo)Examples Live Demox1
Read MoreHow to italicize boxplot label in R using ggplot2?
Like every other tool for statistical analysis R does not display the labels of a boxplot in italics, thus if we want to do this, we need to do it manually. In ggplot2, we have a function scale_x_discrete that can be used to change the default font to italic using expression function.Example Live DemoConsider the below data frame −set.seed(121) x
Read MoreHow to add named vectors of different sizes based on names in R?
If we have named vectors but the names come from same family then they cannot be added to each other direct to get the sum of values based on names. To do this, we need to use tapply function. For example, if we have three vectors defined as x, y, and z then firstly they need to be combined as V
Read MoreHow to convert a vector into data frame in R?
If we want to convert an object into a data frame then as.data.frame function can be used, we just need to read the object that we want to convert with as.data.frame. For example, if we have a vector x then it can be converted to data frame by using as.data.frame(x) and this can be done for a matrix as well.Example1 Live Demox
Read MoreHow to create a regression model in R with interaction between all combinations of two variables?
The easiest way to create a regression model with interactions is inputting the variables with multiplication sign that is * but this will create many other combinations that are of higher order. If we want to create the interaction of two variables combinations then power operator can be used as shown in the below examples.Example1 Live Demox1
Read MoreWhat is the difference between ordered factors and unordered factors in R?
To understand the difference ordered factors and unordered factors, it is better to understand them by creating the factor vectors by using ordered argument with TRUE and FALSE options. For example, if we have a vector x then it can be ordered or unordered as factor(x,ordered=TRUE) and factor(x,ordered=FALSE).Example1 Live Demox1
Read MoreHow to combine array of vectors in R?
To combine array of vectors we can use rbind function. For example, if we have multiple vectors say x, y, z of same size or different sizes but the total number of elements are even then we can use rbind(x,y,z) to combine those vectors. Check out the examples to understand how it works.Example1 Live Demox1
Read MoreHow to convert factor levels into character in R?
To convert factor levels into character then we can use as.character function by accessing the column of the data frame that contain factor values. For example, if we have a data frame df which contains a factor column named as Gender then this column can be converted into character column as as.character(df$Gender).Example Live DemoConsider the below data frame −set.seed(121) x1
Read MoreHow to find p-value for correlation coefficient in R?
The t test is used to find the p−value for the correlation coefficient and on the basis of that we decide whether there exists a statistically significant relationship between two variables or not. In R, we can perform this test by using function cor.test. For example, if we have a vector x and y then we can find the p−value using cor.test(x,y).Example1 Live Demoset.seed(444) x1
Read MoreHow to generate a power sequence of two in R?
In R, for the calculation of power we can simply use power operator ^ and this will be also used in case of generating a power sequence. For example, if we want to generate a power sequence from 1 to 5 of 2 then we can use the code 2^(1:5) this will result 2 4 8 16 32.Example Live Demo2^(0:2)Output[1] 1 2 4Example Live Demo2^(0:10)Output[1] 1 2 4 8 16 32 64 128 256 512 1024 Example Live Demo2^(0:50)Output[1] 1.000000e+00 2.000000e+00 4.000000e+00 8.000000e+00 1.600000e+01 [6] 3.200000e+01 6.400000e+01 1.280000e+02 2.560000e+02 5.120000e+02 [11] 1.024000e+03 2.048000e+03 4.096000e+03 8.192000e+03 1.638400e+04 [16] 3.276800e+04 6.553600e+04 1.310720e+05 2.621440e+05 5.242880e+05 [21] ...
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