Programming Articles

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How to Handle Large CSV files with Pandas?

Sasanka Chitrakavi
Sasanka Chitrakavi
Updated on 23-Oct-2020 2K+ Views

In this post, we will go through the options handling large CSV files with Pandas.CSV files are common containers of data, If you have a large CSV file that you want to process with pandas effectively, you have a few options.Pandas is an in−memory toolYou need to be able to fit your data in memory to use pandas with it. If you can process portions of it at a time, you can read it into chunks and process each chunk. Alternatively, if you know that you should have enough memory to load the file, there are a few hints to ...

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How to apply manually created x-axis labels in a histogram created by hist function in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 19-Oct-2020 3K+ Views

When we generate a histogram in R using hist function, the x-axis labels are automatically generated but we might want to change them to values defined by researchers or by any other authority. Therefore, firstly we need to create the histogram by ignoring the labels and then axis function can be used for new values.Consider the below vector x and create a histogram of x by ignoring x-axis labels −Exampleset.seed(1999) x

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How to create multiple plots of different sizes in base R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 19-Oct-2020 423 Views

Often, we have multiple values, vectors or columns of an R data frame that needs to be plotted on a single graph so that we can compare them at the same time or they have some kind of relationship among them. Therefore, we can use layout function along with matrix function to divide the plot window as shown in the below exampleConsider the below layout and plot of individual values −Examplelayout(matrix(c(1, 2, 3, 3, 4, 5, 6, 6), nrow=4, ncol=2, byrow=FALSE)) plot(500) plot(525) plot(530) plot(531) plot(540) plot(528)OutputChanging the layout and creating the plots −Examplelayout(matrix(c(1, 2, 3, 3, 4, 5, 6, ...

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How to deal with warning message `stat_bin()` using `bins = 30`. Pick better value with `binwidth`. in R while creating a histogram?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 18-Oct-2020 8K+ Views

The default value for bins is 30 but if we don’t pass that in geom_histogram then the warning message is shown by R in most of the cases. To avoid that, we can simply put bins=30 inside the geom_histogram() function. This will stop showing the warning message.Consider the below data frame −x

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How to find the day of the year from dates in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 17-Oct-2020 8K+ Views

To find the day of the year from dates, we can use yday function of lubridate package. For example, if we have a date or a date of vectors then we simply need to pass that date or the vector inside yday function by using the below syntax −yday(“date”)oryday(“vector_of_date”)Loading lubridate package −library(lubridate)Examplesdate1

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How to convert a list of lists into a single list in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 17-Oct-2020 2K+ Views

A list can contain multiple lists of different type as well as similar type elements such as data frames, vectors, matrices etcetera but accessing those elements become a little difficult task. Therefore, it is better to convert a list that contain multiple lists into a single list and it can be done using unlist function.ExampleConsider the below vectors −set.seed(871) x1

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How to extract string before slash from a vector in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 17-Oct-2020 3K+ Views

If a vector contains string values and they are separated with a special character (This special character can be anything, also it is not necessarily to be a special character) and we want to extract only the values that exists before that special then we can use gsub function. For example, if we have a vector x that contain "UT/YT", "IST/IT", "PST/PT" then gsub can help us to extract UT, IST, PST.Examplex1

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Building an array from a string in JavaScript

AmitDiwan
AmitDiwan
Updated on 17-Oct-2020 161 Views

We have to write a function that creates an array with elements repeating from the string till the limit is reached.Suppose there is a string ‘aba’ and a limit 5.e.g. string = "string" and limit = 8 will give new arrayconst arr = ["s", "t", "r", "i", "n", “g”, “s”, ”t”]ExampleLet’s write the code for this function −const string = 'Hello'; const limit = 15; const createStringArray = (string, limit) => {    const arr = [];    for(let i = 0; i < limit; i++){       const index = i % string.length;       arr.push(string[index]);   ...

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How to extract website name from their links in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 16-Oct-2020 288 Views

If we have a list of website links and we want to extract the website name from those links then it is a time-consuming task because we would need to copy each name one-by-one. Therefore, it is better to extract them using a function in R and save time. To extract the website name from the website link, we can use suffix_extract function of urltools package. This will extract the host, subdomain, domain and suffix. And it is known that the domain values are the website names.Loading urltools package −library(urltools)Website links stored in a vector −Web_Links

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How to find the name of the author of a package in R?

Nizamuddin Siddiqui
Nizamuddin Siddiqui
Updated on 16-Oct-2020 524 Views

There can be multiple authors of a package in R and we might want to use their name if we are using their package in our publication for research, books, courses or any other type of content. Therefore, it is required to find out all the authors who contributed to a particular package and this can be done by using citation function with package name as shown in the below examples.Examplecitation("ggplot2")To cite ggplot2 in publications, please use −H. Wickham. ggplot2: Elegant Graphics for Data Analysis. Springer-Verlag New York, 2016.A BibTeX entry for LaTeX users is@Book{,    author = {Hadley Wickham}, ...

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