[R] if statement and for loop question

[Jeff Newmiller]

Can you make R code that creates an actual sample data frame that looks like you want the answer to look? say, just using the data.frame function and literal strings. Oh, and read the Posting Guide... you need to send your email using plain text format or it may get garbled when the list strips the HTML formatting.

On May 30, 2021 9:28:52 AM PDT, Kai Yang via R-help <r-help using r-project.org> wrote:
>Hello List,I have a data frame which having the character columns:
>
>| a1 | b1 | c1 | d1 |
>| a2 | b2 | c2 | d2 |
>| a3 | b3 | c3 | d3 |
>| a4 | b4 | c4 | d4 |
>| a5 | b5 | c5 | d5 |
>
>
>
>I need to do: if a1 not = "Positive" and not = "VUS" then values of 
>b1, c1 and d1 will be zero out. And do the same thing for the a2 to a5
>series.
>I write the code below to do this. But it doesn't work. Would you
>please correct my code?
>Thank you,
>Kai
>
>
>for (i in 1:5) 
>{
>  if (isTRUE(try$a[i] != "Positive" && try$a[i] != "VUS"))
>  {
>    try$b[i]== ''
>    try$c[i] == ''
>    try$d[i]== ''
>  }
>}
>
>
>	[[alternative HTML version deleted]]
>
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-- 
Sent from my phone. Please excuse my brevity.