# Convert a Data Frame into a Molten Form in R Programming – melt() Function

• Last Updated : 17 Jun, 2020

function in R Language is used to combine multiple columns of s Data Frame into a single column.

Syntax: melt(x, na.rm, value.name)

Parameters:
x: data to be melted
na.rm: Boolean value to remove NA
value.name: Setting column names

Example 1:

 `# R program to reshape data frame`` ` `# Loading library``library(reshape) `` ` `# Creating a data frame``a <``-` `data.frame(``id` `=` `c(``"1"``, ``"1"``, ``"2"``, ``"2"``), ``                ``points ``=` `c(``"1"``, ``"2"``, ``"1"``, ``"2"``), ``                ``x1 ``=` `c(``"5"``, ``"3"``, ``"6"``, ``"2"``), ``                ``x2 ``=` `c(``"6"``, ``"5"``, ``"1"``, ``"4"``)) ``a`` ` `# Calling melt() Function``m <``-` `melt(a, ``id` `=` `c(``"id"``, ``"points"``)) ``print``(m) `

Output:

```  id points x1 x2
1  1      1  5  6
2  1      2  3  5
3  2      1  6  1
4  2      2  2  4
id points variable value
1  1      1       x1     5
2  1      2       x1     3
3  2      1       x1     6
4  2      2       x1     2
5  1      1       x2     6
6  1      2       x2     5
7  2      1       x2     1
8  2      2       x2     4
```

Example 2:

 `# R program to reshape data frame`` ` `# Loading library``library(reshape2) `` ` `# Calling pre-defined data set``BOD`` ` `# Calling melt() Function``m <``-` `melt(BOD, variable.name ``=` `"Stat"``, value.name ``=``"Data"``) ``print``(m) `

Output:

```  Time demand
1    1    8.3
2    2   10.3
3    3   19.0
4    4   16.0
5    5   15.6
6    7   19.8
No id variables; using all as measure variables
Stat Data
1    Time  1.0
2    Time  2.0
3    Time  3.0
4    Time  4.0
5    Time  5.0
6    Time  7.0
7  demand  8.3
8  demand 10.3
9  demand 19.0
10 demand 16.0
11 demand 15.6
12 demand 19.8
```

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