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Nizamuddin Siddiqui has Published 2307 Articles

Nizamuddin Siddiqui
938 Views
Random sampling helps us to reduce the biasedness in the analysis. If we have data in groups then we might want to find a random sample based on groups. For example, if we have a data frame with a group variable and each group contains ten values then we might ... Read More

Nizamuddin Siddiqui
463 Views
We know that a list in R can have multiple elements of different data types but they can be the same as well. Whether we have the same type of elements or different ones, we might want to subset the list with unique values, especially in situations where we believe ... Read More

Nizamuddin Siddiqui
726 Views
To apply shapiro wilk test for normality on vectors, we just simply name the vector inside shapiro.test function but if we want to do the same for an R data frame column then the column will have to specify the column in a proper way. For example, if the data ... Read More

Nizamuddin Siddiqui
811 Views
The power of a matrix in R cannot be found directly because there is not function in base R for that. Therefore, for this purpose we can use %^% of expm package. Firstly, we will install the expm package then load it and use %^%. For example, suppose we have ... Read More

Nizamuddin Siddiqui
576 Views
When we draw a scatterplot using ggplot2 with points based on a sequence of values then the size of the points might be very small for the small values. As a result, it becomes a little difficult to view the points. Therefore, we might want to increase the size of ... Read More

Nizamuddin Siddiqui
950 Views
A list sometimes contains NULL elements along with other elements. Therefore, we might want to get rid of that NULL element so that we can use our list without any hustle. To do this, we can use lapply function with the following syntax −Syntax“List_name”[!unlist(lapply(“List_name”, is.null))]ExampleConsider the below list − Live Demox1Read More

Nizamuddin Siddiqui
654 Views
A list contains different type of elements and each of the them can have varying elements. To subset these sub-elements we can use sapply function and use c to subset the number of corresponding sub-elements. For example, if we have a list that contains five elements and each of those ... Read More

Nizamuddin Siddiqui
526 Views
If we have an data.table object or a data frame converted to a data.table and it has a factor column then we might want to create a frequency table that shows the number of values each factor has or the count of factor levels. This is a data summarization method ... Read More

Nizamuddin Siddiqui
2K+ Views
The cor function in R helps us to find the correlation matrix from a data frame or a matrix but the output of it always a matrix as intended. We might want to convert that matrix into a data frame which consists of all combination of variables with their correlation ... Read More

Nizamuddin Siddiqui
200 Views
If an R data frame contains all numerical columns and we want to find the difference between row values then we will lose first row of the data frame because that will not be subtracted from any row. This can be done by using head function and minus sign. It ... Read More