[R] Mean: category wise within a data frame

[David Carlson]

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As to your question. Look at the aggregate() function:

?aggregate

David Carlson

-----Original Message-----
From: r-help-bounces at r-project.org
[mailto:r-help-bounces at r-project.org] On Behalf Of Nandini
Jayakumar
Sent: Tuesday, December 24, 2013 4:36 AM
To: r-help at r-project.org
Subject: [R] Mean: category wise within a data frame

Hello all

I have a table a sample of which is as follows:




	
	
	
	



	
	
	
	
		
			Categories

		
		
			Variable (x)

		
		
			Frequencies

		
	
	
		
			1

			1

			1

			1

			1

		
		
			0.009

			0.867

			0.567

			0.765

			0.445

		
		
			1003

			1200

			987

			134

			890

		
	
	
		
			2

			2

			2

			2

			2

		
		
			0.007

			0.768

			0.789

			0.544

			0.987

		
		
			899

			707

			865

			678

			889

		
	
	
		
			3

			3

			3

			3

			3

		
		
			0.898

			0.887

			0.560

			0.098

			0.987

		
		
			544

			677

			934

			467

			876

		
	
	
		
			40

			40

			40

			40

			40

		
		
			0.786

			0.342

			0.456

			0.987

			0.123

		
		
			843

			987

			675

			467

			223

		
	



Basically I have 40 categories and each category has several
hundred variables. I want to calculate the average per category,
that is variable * frequency/Summation of frequencies. I want to
do it for each category separately. Since i have many categories
i do not want to use the subset() function 40 times. Is it
possible to do it within a single data frame?

Really appreciate any help. Thank you.
 		 	   		  
	[[alternative HTML version deleted]]

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