[R] R help

Jeff Newmiller jdnewmil at dcn.davis.CA.us
Mon Oct 14 08:50:45 CEST 2013

Why? I assume you posted because you want help with something, but it is going to be very difficult to help if you don't know the most basic things about R or this mailing list.
Spreadsheet: R can import data from a spreadsheet, but the corresponding native terminology in R is "data.frame" or "matrix" depending on what kind of data you are working with. This is important because R does not behave at all like a spreadsheet and you will confuse us and yourself if you get this mixed up.
For loop: It is unusual to do most calculations in R with for loops. It is almost always better to use vector calculations and indexing. Read the Introduction to R document that comes with R. In particular, per your question, logical indexing or the subset function can be used to find particular values.
If else: There are two forms of if-else in R. The if function is used for choosing among code blocks, while the ifelse function is used for vector calculations. I imagine you were thinking of the former, but in many cases the latter is more appropriate.
Mailing list: Please read the Posting Guide. Posting in HTML is strongly discouraged, as it makes a mess of R code. Learn how to send plain text emails. Also, this is not a homework help forum, so if this is related to a class then get help there because we don't know what your instructor thinks is fair help. Finally, please show us what you have already tried including input data (this is known as providing a reproducible example).
If this all seems a bit much then you are probably in the wrong place. It takes some effort to make sure your question is understood using only email. Fortunately, once you learn the basics of the R language it is possible to communicate very precisely in email.
Jeff Newmiller                        The     .....       .....  Go Live...
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Sent from my phone. Please excuse my brevity.

Shameem Akhtar <sham3287 at gmail.com> wrote:
>             I want to use for loop and if..else condition together for
>finding such value from a two column in a spreadsheet.
>Thanks & Regards
>Shameem Akhtar
>	[[alternative HTML version deleted]]
>R-help at r-project.org mailing list
>PLEASE do read the posting guide
>and provide commented, minimal, self-contained, reproducible code.

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