# Selectively Print Lines of a Text Vector Given one or two regular expressions or exact text matches, removes elements of the input vector that match these specifications. Omitted lines are replaced by . This is useful for selectively suppressing some of the printed output of R functions such as regression fitting functions, especially in the context of making statistical reports using Sweave or Odfweave. 1.1 ```r prselect(x, start = NULL, stop = NULL, i = 0, j = 0, pr = TRUE) ``` ## Arguments - `x`: input character vector - `start`: text or regular expression to look for starting line to omit. If omitted, deletions start at the first line. - `stop`: text or regular expression to look for ending line to omit. If omitted, deletions proceed until the last line. - `i`: increment in number of first line to delete after match is found - `j`: increment in number of last line to delete after match is found - `pr`: set to `FALSE` to suppress printing ## Returns an invisible vector of retained lines of text ## Author(s) Frank Harrell ## See Also `Sweave` ## Examples ```r x <- c('the','cat','ran','past','the','dog') prselect(x, 'big','bad') # omit nothing- no match prselect(x, 'the','past') # omit first 4 lines prselect(x,'the','junk') # omit nothing- no match for stop prselect(x,'ran','dog') # omit last 4 lines prselect(x,'cat') # omit lines 2- prselect(x,'cat',i=1) # omit lines 3- prselect(x,'cat','past') # omit lines 2-4 prselect(x,'cat','past',j=1) # omit lines 2-5 prselect(x,'cat','past',j=-1)# omit lines 2-3 prselect(x,'t$','dog') # omit lines 2-6; t must be at end # Example for Sweave: run a regression analysis with the rms package # then selectively output only a portion of what print.ols prints. # (Thanks to \email{romain.francois@dbmail.com}) # <>= # library(rms) # y <- rnorm(20); x1 <- rnorm(20); x2 <- rnorm(20) # ols(y ~ x1 + x2) # <>= # z <- capture.output( { # <> # } ) # prselect(z, 'Residuals:') # keep only summary stats; or: # prselect(z, stop='Coefficients', j=-1) # keep coefficients, rmse, R^2; or: # prselect(z, 'Coefficients', 'Residual standard error', j=-1) # omit coef # @ ```

prselect function