R: Expression substitution

es {ore} | R Documentation

## Expression substitution

### Description

Evaluate R expressions and substitute their values into one or more strings.

### Usage

    es(text, round = NULL, signif = NULL, envir = parent.frame())

### Arguments

`text` | A vector of strings to substitute into.
`round` | `NULL` or a single integer, giving the number of decimal digits for rounding numeric expressions. This argument takes priority over `signif`.
`signif` | `NULL` or a single integer, giving the number of significant decimal digits to use for numeric expressions. The `round` argument takes priority over this one, and will be used if not `NULL`.
`envir` | The environment to evaluate expressions in.

### Details

Each part of the string surrounded by `"#{}"` is extracted, evaluated as R code in the specified environment, and then its value is substituted back into the string. The literal string `"#{}"` can be obtained by escaping the hash character, viz. `"\\#{}"`. The block may contain multiple R expressions, separated by semicolons, but may not contain additional braces. Its value will be coerced to character mode, and if the result has multiple elements then the source string will be duplicated.

### Value

The final strings, with expression values substituted into them.

### See Also

`ore_subst`

### Examples

    es("pi is #{pi}")
    es("pi is \\#{pi}")
    es("The square-root of pi is approximately #{sqrt(pi)}", signif=4)
    es("1/(1+x) for x=3 is #{x <- 3; 1/(1+x)}")

[Package ore version 1.7.0 Index]