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Rearranging data frame from column names to key value pairs

3

$begingroup$

If I have data like this in R:

> a = data.frame(a = c(1, 2),
 b = c(3, 4))
> a
 a b
1 1 3
2 2 4

but I would like to have it like this:

> b = data.frame(k = c("a", "a", "b", "b"),
+ v = c(1, 2, 3, 4))
> b
 k v
1 a 1
2 a 2
3 b 3
4 b 4

How can I convert the data this way?

r data

share|improve this question

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

$endgroup$

add a comment | 

3

$begingroup$

If I have data like this in R:

> a = data.frame(a = c(1, 2),
 b = c(3, 4))
> a
 a b
1 1 3
2 2 4

but I would like to have it like this:

> b = data.frame(k = c("a", "a", "b", "b"),
+ v = c(1, 2, 3, 4))
> b
 k v
1 a 1
2 a 2
3 b 3
4 b 4

How can I convert the data this way?

r data

share|improve this question

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

$endgroup$

add a comment | 

$begingroup$

If I have data like this in R:

> a = data.frame(a = c(1, 2),
 b = c(3, 4))
> a
 a b
1 1 3
2 2 4

but I would like to have it like this:

> b = data.frame(k = c("a", "a", "b", "b"),
+ v = c(1, 2, 3, 4))
> b
 k v
1 a 1
2 a 2
3 b 3
4 b 4

How can I convert the data this way?

r data

share|improve this question

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

$endgroup$

> a = data.frame(a = c(1, 2),
 b = c(3, 4))
> a
 a b
1 1 3
2 2 4

> b = data.frame(k = c("a", "a", "b", "b"),
+ v = c(1, 2, 3, 4))
> b
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this question

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

share|improve this question

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

edited Apr 4 at 14:06

Stephen Rauch♦

1,52551330

asked Apr 4 at 13:14

MartinMartin

183

asked Apr 4 at 13:14

MartinMartin

183

2 Answers
2

active

oldest

votes

2

$begingroup$

This is a simple gather() using package tidyr:

> library(tidyr)
> 
> gather(a, key = "k", value = "v")
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:09

AdamAdam

1363

$endgroup$

add a comment | 

2

$begingroup$

You can alternatively use the melt() function from the reshape2 package

> library(reshape2)
> 
> melt(a, variable.name="k", value.name="v")
No id variables; using all as measure variables
 k v
1 a 1
2 a 2
3 b 3
4 b 4

Hope this is insightful!

share|improve this answer

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

$endgroup$

add a comment | 

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2

$begingroup$

This is a simple gather() using package tidyr:

> library(tidyr)
> 
> gather(a, key = "k", value = "v")
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:09

AdamAdam

1363

$endgroup$

add a comment | 

2

$begingroup$

This is a simple gather() using package tidyr:

> library(tidyr)
> 
> gather(a, key = "k", value = "v")
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:09

AdamAdam

1363

$endgroup$

add a comment | 

$begingroup$

This is a simple gather() using package tidyr:

> library(tidyr)
> 
> gather(a, key = "k", value = "v")
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:09

AdamAdam

1363

$endgroup$

> library(tidyr)
> 
> gather(a, key = "k", value = "v")
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:09

AdamAdam

1363

answered Apr 4 at 15:09

AdamAdam

1363

answered Apr 4 at 15:09

AdamAdam

1363

2

$begingroup$

You can alternatively use the melt() function from the reshape2 package

> library(reshape2)
> 
> melt(a, variable.name="k", value.name="v")
No id variables; using all as measure variables
 k v
1 a 1
2 a 2
3 b 3
4 b 4

Hope this is insightful!

share|improve this answer

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

$endgroup$

add a comment | 

2

$begingroup$

You can alternatively use the melt() function from the reshape2 package

> library(reshape2)
> 
> melt(a, variable.name="k", value.name="v")
No id variables; using all as measure variables
 k v
1 a 1
2 a 2
3 b 3
4 b 4

Hope this is insightful!

share|improve this answer

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

$endgroup$

add a comment | 

$begingroup$

You can alternatively use the melt() function from the reshape2 package

> library(reshape2)
> 
> melt(a, variable.name="k", value.name="v")
No id variables; using all as measure variables
 k v
1 a 1
2 a 2
3 b 3
4 b 4

Hope this is insightful!

share|improve this answer

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

$endgroup$

> library(reshape2)
> 
> melt(a, variable.name="k", value.name="v")
No id variables; using all as measure variables
 k v
1 a 1
2 a 2
3 b 3
4 b 4

share|improve this answer

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213

answered Apr 4 at 15:40

I'mAnAccountantIKnowAlotOfMathI'mAnAccountantIKnowAlotOfMath

1213