Macro variables in R

Question

I wonder how to use macros in R.

I´m looking for a simple macro so I only need to change for example a date once in a syntax and not on every place where the date is used in the syntax.

In other words like the %let functions in SAS but in R.

You're going to have to be (much) more specific if you want a helpful answer. — joran, Jun 09 '17 at 15:05
Put additions and changes to your question in your _question_, not in the comment, please. — joran, Jun 09 '17 at 15:08
R is not SAS. R is a programming language, not a macro language. There is no such thing as a "macro" in R. The closest R equivalent of `%let` is the assignment operator ` — Joris Meys, Jun 09 '17 at 15:18
Often people will use `sprintf` for this: `sprintf("select * from blah where var = %s",date)`. — joran, Jun 09 '17 at 15:52
like this? sprintf("select * from FactStoreSale where var = %s",date) ? — Sven Johansson, Jun 09 '17 at 16:12
Possible duplicate of [How do I use a macro variable in R? (Similar to %LET in SAS)](https://stackoverflow.com/questions/28484072/how-do-i-use-a-macro-variable-in-r-similar-to-let-in-sas) — Jthorpe, Jun 09 '17 at 16:55
I'm still strugling with this despite all great suggestions... This is how I normaly does it TD = '2016-03-27' " ) Now I want to make the date filter dynamic,a date variable 1 year back in time created in R that I can use i an SQLQuery in R. TD = ???? " ) — Sven Johansson, Jun 12 '17 at 12:35

score 1 · Answer 1 · answered Jun 09 '17 at 16:50

a closerlook would suggest that creating your own custom function in R and then calling that function would be like a SAS Macro

e.g

myfunction=function(x){ whatever the macro would do pseduo code}

and then call the function

myfunction(var1)

for %let which is a global variable just assign the value to a constant

but overall quit thinking like SAS and switch to object oriented programming in R

score 0 · Answer 2 · answered Jun 09 '17 at 16:46

0

Use a constant instead of explicitly writing it out every time?

answered Jun 09 '17 at 16:46

TaintedQ

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Macro variables in R

2 Answers2