# How to create a subset in r

### What is subset in R?

Subsetting in

**R**is a useful indexing feature for accessing object elements. It can be used to select and filter variables and observations. You can use brackets to select rows and columns from your dataframe.### What package is subset in R?

The

**subset**function is available in base**R**and can be used to return**subsets**of a vector, martix, or data frame which meet a particular condition. In my three years of using**R**, I have repeatedly used the**subset**() function and believe that it is the most useful tool for selecting elements of a data structure.### How do I select certain rows in R?

**Subset**Data Frame**Rows in R**- slice(): Extract
**rows**by position. - filter(): Extract
**rows**that meet a**certain**logical criteria. - filter_all(), filter_if() and filter_at(): filter
**rows**within a**selection**of variables. - sample_n(): Randomly
**select**n**rows**. - sample_frac(): Randomly
**select**a fraction of**rows**. - top_n():
**Select**top n**rows**ordered by a variable.

### How do you sort data in R?

To

**sort**a**data**frame in**R**, use the order( ) function. By default, sorting is ASCENDING. Prepend the sorting variable by a minus sign to indicate DESCENDING order.### How do you omit rows in R?

**Delete Rows**from

**R**Data Frame

You cannot actually **delete** a **row**, but you can access a data frame without some **rows** specified by negative index. This process is also called subsetting in **R** language. A Big Note: You should provide a comma after the negative index vector -c().

### How do I replace NAs with 0 in R?

To

**replace NA with 0**in an**R**data frame, use is.**na**() function and then select all those values with**NA**and assign them to**0**. myDataframe is the data frame in which you would like**replace**all**NAs with 0**.### How do I create a new data frame in R?

We can

**create**a**dataframe in R**by passing the variable a,b,c,d into the data. frame() function. We can**R create dataframe**and name the columns with name() and simply specify the name of the variables.### How do I convert character to numeric in R?

numerical. To

**convert**a**character**vector to a**numeric**vector, use as.**numeric**(). It is important to do this before using the vector in any statistical functions, since the default behavior in**R**is to**convert character**vectors to factors.### How does as numeric work in R?

The as.

**numeric**() method takes an**R**object that needs to be coerced and returns the converted**numeric**value. The**numeric**() function is identical to double() method. It creates a double-precision vector of the defined length with each item equal to 0.### How do I convert a character to a factor in R?

- Gender. and.
- Type. are.
**char**. variables. Let’s**convert**them to**factors**. df[sapply(df, is.**character**)] <- lapply(df[sapply(df, is.**character**)], as.**factor**) df[sapply(df, is.**character**)] <- lapply(df[sapply(df, is.**character**)], as.**factor**) df[sapply(df, is.**character**)] <- lapply(df[sapply(df, is.**character**)], as.**factor**)

### What does DBL mean in R?

**dbl**stands for double class. A double-precision floating point number. Fer May 12, 2019, 10:34pm #3. It is a data type defined to hold numeric values with decimal points (

**dbl**came from double). The alternative, integer, is defined for integer numbers.

### What is factor R?

**Factor in R**is a variable used to categorize and store the data, having a limited number of different values. It stores the data as a vector of integer values.

**Factor in R**is also known as a categorical variable that stores both string and integer data values as levels.

### What does LBL mean in R?

Value labels in the ipumsr package

The tibble package prints the variable’s type information below the variable name, and this “+**lbl**” indicates that the variable uses the labelled type. The function **is**. labelled() **will** also tell you if a variable **is** labelled.

### What is the difference between numeric and double in R?

It is a historical anomaly that

**R**has two names for its floating-point vectors,**double**and**numeric**(and formerly had real ).**double**is the name of the type.**numeric**is the name of the mode and also of the implicit class. As an S4 formal class, use “**numeric**” .### Is double in R?

The two most common numeric classes used in

**R are**integer and**double**(for**double**precision floating point numbers).**R**automatically converts between these two classes when needed for mathematical purposes.**As a**result, it’s feasible to use**R**and perform analyses for years without specifying these differences.### Does R have integers?

Note that current implementations of

**R**use 32-bit**integers**for**integer**vectors, so the range of representable**integers is**restricted to about \(\pm 2 \times 10^9\): double s can hold much larger**integers**exactly.### What is a numeric class in R?

The “

**numeric**”**class in R**has multiple**classes**grouped under it. The two most common among them are double (for double-precision floating-point numbers)**class**and integer**class**.**R**automatically converts between the**numeric classes**when needed.### What is NaN called?

In computing,

**NaN**(/næn/), standing for Not a Number, is a member of a numeric data type that can be interpreted as a value that is undefined or unrepresentable, especially in floating-point arithmetic.**NaNs**may also be used to represent missing values in computations.### What is raw data type in R?

The

**raw type**is intended to hold**raw**bytes. It is possible to extract subsequences of bytes, and to replace elements (but only by elements of a**raw**vector). A**raw**vector is printed with each byte separately represented as a pair of hex digits.### What is difference between numeric and integer in R?

As you can see “

**integer**” is a subset of “**numeric**“.**Integers**only go to a little more than 2 billion, while the other numerics can be much bigger. They can be bigger because they are stored as double precision floating point numbers. For example, 1:5 creates an**integer**vector of numbers from 1 to 5.### What are the basic data types in R?

**R’s basic data types**are character, numeric, integer, complex, and logical.

**R’s basic data**structures include the vector, list, matrix,

**data**frame, and factors.

### Is numeric () in R?

is.

**numeric**returns TRUE if its argument is of type real or type integer and FALSE otherwise.