CODEWITHSUNDEEP
rdataframemean
raktim
raktim

Reputation: 1

Writing a function to calculate a general mean based on specific function call by the user

I'm using Rstudio version 1.10.136 in Mac OS Sierra 10.12.2 and here's what I want to do. I have a set of data and I created a data frame and then I filtered it after removing the NA and it looks like this:

            Date sulfate nitrate ID
279   2003-10-06  7.2100  0.6510  1
285   2003-10-12  5.9900  0.4280  1
291   2003-10-18  4.6800  1.0400  1
297   2003-10-24  3.4700  0.3630  1
303   2003-10-30  2.4200  0.5070  1

Now I want to calculate the mean based on ID call such as:

mean("specdata_subset", "sulfate", 1:10)

or 

mean("specdata_subset", "nitrate", 40)

How do I write a general function that helps me calculate mean based on the ID numbers.

Upvotes: 0

Views: 54

Answers (1)

Paulo MiraMor
Paulo MiraMor

Reputation: 1610

Use aggregate():

aggregate(nitrate~ID, df,  mean)
aggregate(sulfate~ID, df,  mean)

Data:

df <- read.table(text = '
Date sulfate nitrate ID
279   2003-10-06  7.2100  0.6510  1
285   2003-10-12  5.9900  0.4280  1
291   2003-10-18  4.6800  1.0400  1
297   2003-10-24  3.4700  0.3630  1
303   2003-10-30  2.4200  0.5070  1')

Upvotes: 1

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