R: Querying/setting evals option

evalsOptions {pander} | R Documentation

## Querying/setting evals option

### Description

To list all `evals` options, just run this function without any parameters provided. To query only one value, pass the first parameter. To set that, use the `value` parameter too.

### Usage

    evalsOptions(o, value)

### Arguments

`o` | option name (string). See below.
`value` | value to assign (optional)

### Details

The following `evals` options are available:

- `parse`: if `TRUE` the provided `txt` elements would be merged into one string and parsed to logical chunks. This is useful if you would want to get separate results of your code parts - not just the last returned value, but you are passing the whole script in one string. To manually lock lines to each other (e.g. calling a `plot` and on next line adding an `abline` or `text` to it), use a plus char (`+`) at the beginning of each line which should be evaluated with the previous one(s). If set to `FALSE`, `evals` would not try to parse R code, it would get evaluated in separate runs - as provided. Please see examples of `evals`.

- `cache`: caching the result of R calls if set to `TRUE`

- `cache.mode`: cached results could be stored in an `environment` in current R session or let it be permanent on `disk`.

- `cache.dir`: path to a directory holding cache files if `cache.mode` set to `disk`. Default to `.cache` in current working directory.

- `cache.time`: number of seconds to limit caching based on `proc.time`. If set to `0`, all R commands, if set to `Inf`, none is cached (despite the `cache` parameter).

- `cache.copy.images`: copy images to new files if an image is returned from cache? If set to `FALSE` (default) the "old" path would be returned.

- `classes`: a vector or list of classes which should be returned. If set to `NULL` (by default) all R objects will be returned.

- `hooks`: list of hooks to be run for given classes in the form of `list(class = fn)`. If you would also specify some parameters of the function, a list should be provided in the form of `list(fn, param1, param2=NULL)` etc. So the hooks would become `list(class1=list(fn, param1, param2=NULL), ...)`. See examples of `evals`. A default hook can be specified too by setting the class to `'default'`. This can be handy if you do not want to define separate methods/functions to each possible class, but automatically apply the default hook to all classes not mentioned in the list. You may also specify only one element in the list like: `hooks=list('default' = pander_return)`. Please note, that nor error/warning messages, nor stdout is captured (so: updated) while running hooks!

- `length`: any R object exceeding the specified length will not be returned. The default value (`Inf`) does not filter out any R objects.

- `output`: a character vector of required returned values. This might be useful if you are only interested in the `result`, and do not want to save/see e.g. `messages` or `print`ed `output`. See examples of `evals`.

- `graph.unify`: boolean (default: `FALSE`) that determines if `evals` should try to unify the style of (`base`, `lattice` and `ggplot2`) plots? If set to `TRUE`, some `panderOptions()` would apply.

- `graph.name`: set the file name of saved plots which is `tempfile` by default. A simple character string might be provided where `%d` would be replaced by the index of the generating `txt` source, `%n` with an incremented integer in `graph.dir` with similar file names and `%t` by some random characters. A function's name to be `eval`uated can be passed here too.

- `graph.dir`: path to a directory where to place generated images. If the directory does not exist, `evals` try to create that. Default set to `plots` in current working directory.

- `graph.output`: set the required file format of saved plots. Currently it could be any of `grDevices`: `png`, `bmp`, `jpeg`, `jpg`, `tiff`, `svg` or `pdf`. Set to `NA` not to save plots at all and tweak that setting with `capture.plot()` on demand.

- `width`: width of generated plot in pixels for even vector formats

- `height`: height of generated plot in pixels for even vector formats

- `res`: nominal resolution in `ppi`. The height and width of vector images will be calculated based in this.

- `hi.res`: generate high resolution plots also? If set to `TRUE`, each R code parts resulting an image would be run twice.

- `hi.res.width`: width of generated high resolution plot in pixels for even vector formats. The `height` and `res` of high resolution image is automatically computed based on the above options to preserve original plot aspect ratio.

- `graph.env`: save the environments in which plots were generated to distinct files (based on `graph.name`) with `env` extension?

- `graph.recordplot`: save the plot via `recordPlot` to distinct files (based on `graph.name`) with `recodplot` extension?

- `graph.RDS`: save the raw R object returned (usually with `lattice` or `ggplot2`) while generating the plots to distinct files (based on `graph.name`) with `RDS` extension?

- `log`: `NULL` or an optionally passed logger name from futile.logger to record all info, trace, debug and error messages.

### See Also

`evals` `panderOptions`

### Examples

    evalsOptions()
    evalsOptions('cache')
    evalsOptions('cache', FALSE)

[Package pander version 0.6.1 Index]