formatting - R output without [1], how to nicely format?

Question

I know stuff has been posted, but not as complete as what I am looking for.

Take any help function (i.e. ?mean), and realise that it's output (or at least output should be able to be generated in the same manner).

How do you get enters, alignment/intendation?

Example:

strings <- c("t", "df", "p-value", "mean of x", "mean of y")
values  <- c(t, df, pvalue, mean1, mean2)

If this would be the things you'd want to output in R (when called from a function), how do you make the [1] disappear, and the values lined up?

Answer 1

This is rather elementary, please consult An Introduction to R as well as

• help(cat)
• help(sprintf)
• help(format)

and many more. See the (literally thousands) of examples in formatting functions. Here is a simple example from one of my packages:

print.summary.fastLm <- function(x, ...) {
    cat("
Call:
")
    print(x$call)
    cat("
Residuals:
")
    print(x$residSum)
    cat("
")

    printCoefmat(x$coefficients, P.values=TRUE, has.Pvalue=TRUE)
    digits <- max(3, getOption("digits") - 3)
    cat("
Residual standard error: ", formatC(x$sigma, digits=digits), " on ",
        formatC(x$df), " degrees of freedom
", sep="")
    cat("Multiple R-squared: ", formatC(x$r.squared, digits=digits),
        ",Adjusted R-squared: ",formatC(x$adj.r.squared, digits=digits),
        "
", sep="")
    invisible(x)
}