How to access single elements in a table in R

Question

How do I grab elements from a table in R    My Data looks like this            V1     V2 1      12 448 13 919 2      22 242  4 606 3      24 509  0 176   etc     I basically just want to grab elements individually  I m getting confused with all the R terminology like vectors  and I just want to be able to get at the individual elements   Is there a function where I can just do like data v1  1  and get the element in row 1 column 1

User · Accepted Answer

That is so basic that I am wondering what book you are using to study? Try

data[1, "V1"]  # row first, quoted column name second, and case does matter

Further note: Terminology in discussing R can be crucial and sometimes tricky. Using the term "table" to refer to that structure leaves open the possibility that it was either a 'table'-classed, or a 'matrix'-classed, or a 'data.frame'-classed object. The answer above would succeed with any of them, while @BenBolker's suggestion below would only succeed with a 'data.frame'-classed object.

I am unrepentant in my phrasing despite the recent downvote. There is a ton of free introductory material for beginners in R: https://cran.r-project.org/other-docs.html

User · Answer

Maybe not so perfect as above ones  but I guess this is what you were looking for   data 1 1 3 3      works with positive integers data 1 1  -3 -3   does not work  gives the entire 1st row without the 3rd element data i i j j      given that i and j are positive integers   Here indexing will work from 1  i e    data 1 1 1 1      means the top-leftmost element

User · Answer

pretty much covers the various ways of accessing elements of things   Under usage it lists these   x i  x i  j        drop   TRUE  x  i  exact   TRUE   x  i  j       exact   TRUE   x name getElement object  name   x i   lt - value x i  j        lt - value x  i    lt - value x i  lt - value   The second item is sufficient for your purpose  Under Arguments it points out that with   the arguments i and j can be numeric  character or logical  So these work   data 1 1  data 1  V1     As does this   data V1 1    and keeping in mind a data frame is a list of vectors   data  1   1  data   V1    1    will also both work    So that s a few things to be going on with  I suggest you type in the examples at the bottom of the help page one line at a time  yes  actually type the whole thing in one line at a time and see what they all do  you ll pick up stuff very quickly and the typing rather than copypasting is an important part of helping to commit it to memory

[r] How to access single elements in a table in R

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