R Data Frame: Create, Append, Select, Subset.

Conclusion. You just saw how to export a DataFrame to CSV in R. At times, you may face an opposite situation, where you’ll need to import a CSV file into R. If that’s the case, you may want to visit the following source that explains how to import a CSV file into R. Finally, the Data Output documentation is a good source to check for additional information about exporting CSV files in R.

Could you compare vector, matrix, array, list and data.frame? Example representations of different data structures in R. Source: Ceballos and Cardiel 2013. The following data structures are common in R: vector: Contains a sequence of items of the same type. This is most basic structure. Items of a vector can be accessed using (). Function length can be called to know the number of items. list.

Creating dummies for categorical variables - R Data.

This tutorial describes how to reorder (i.e., sort) rows, in your data table, by the value of one or more columns (i.e., variables). You will learn how to easily: Sort a data frame rows in ascending order (from low to high) using the R function arrange() (dplyr package); Sort rows in descending order (from high to low) using arrange() in combination with the function desc() (dplyr package).Make a GRanges object from a data.frame or DataFrame Description. makeGRangesFromDataFrame takes a data-frame-like object as input and tries to automatically find the columns that describe genomic ranges. It returns them as a GRanges object. makeGRangesFromDataFrame is also the workhorse behind the coercion method from data.frame (or DataFrame) to GRanges.Matrix and Dataframes are the important part of Data Structure in R. Many peoples are confused between Matrix and Data frames, they are look-alike but different in natures. So, let’s start the difference between R Matrix and Dataframes with basic.


The dummy.data.frame() function creates dummies for all the factors in the data frame supplied. Internally, it uses another dummy() function which creates dummy variables for a single factor. The dummy() function creates one new variable for every level of the factor for which we are creating dummies. It appends the variable name with the factor level name to generate names for the dummy.Data Type Conversion. Type conversions in R work as you would expect. For example, adding a character string to a numeric vector converts all the elements in the vector to character. Use is.foo to test for data type foo. Returns TRUE or FALSE Use as.foo to explicitly convert it. is.numeric(), is.character(), is.vector(), is.matrix(), is.data.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more Convert a matrix to a data frame. Ask Question Asked 5 years, 10 months ago. Active 5 years, 10 months ago. Viewed 452 times -2. I have generated a matrix called mat in R using 24 datasets. Each dataset has a dimension of (1, 1:10000). I used rbind to combine these 24.

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Transpose. The transpose (reversing rows and columns) is perhaps the simplest method of reshaping a dataset. Use the t() function to transpose a matrix or a data frame. In the latter case, row names become variable (column) names. An example is presented in the next listing. Listing 1 Transposing a dataset.

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An Introduction to Bioconductor’s ExpressionSet Class Seth Falcon, Martin Morgan, and Robert Gentleman 6 October, 2006; revised 9 February, 2007 1 Introduction Biobase is part of the Bioconductor project, and is used by many other packages. Biobase contains standardized data structures to represent genomic data. The ExpressionSet class is designed to combine several di erent sources of.

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Rotating or transposing R objects Two dimensional R objects include data.frame, matrix and table objects. You can transpose the rows and columns using the t() command.

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For each row in an R Data Frame. Import Excel Data into R Dataframe. Convert R Dataframe to Matrix. R Dataframe - Delete Rows. R Dataframe - Drop Columns. R Dataframe - Add Column. R Dataframe - Change Column Name. R Dataframe - Remove Duplicate Rows. R Dataframe - Replace NA with 0. Convert Matrix to R Dataframe. Handling Data from Files. R CSV Files - Read, Filter, Write. R Read Excel XLS.

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Details. If one of nrow or ncol is not given, an attempt is made to infer it from the length of data and the other parameter. If neither is given, a one-column matrix is returned. If there are too few elements in data to fill the matrix, then the elements in data are recycled. If data has length zero, NA of an appropriate type is used for atomic vectors (0 for raw vectors) and NULL for lists.

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If data is a data frame, there may be other columns and the order of columns is not important. Any character variables are coerced to factors. After coercion, all the variables used on the right-hand side of the formula must be logical, integer, numeric or factor.

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I've got matrix: var1 var2 row1 1 2 row2 3 4 Want to convert it to data.frame: rows vars values row1 var1 1 row1 var2 2 row2 var1 3 row2 var2 4.

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Suitable native R types like matrix, data.frame, and ts are supported, as well as contributed ones such as timeSeries, fts and of course zoo. as.xts() is the workhorse function to do the conversions to xts, and similar functions will provide the reverse behavior.

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Convert a data frame, correlation matrix, or factor analysis output to a LaTeX table Description. A set of handy helper functions to convert data frames or matrices to LaTeX tables. Although Sweave is the preferred means of converting R output to LaTeX, it is sometimes useful to go directly from a data.frame or matrix to a LaTeX table. cor2latex will find the correlations and then create a.

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