listFilters: List or search the filters available in the selected dataset
In biomaRt: Interface to BioMart databases (i.e. Ensembl)

Description Usage Arguments Author(s) Examples

Filters are what we use as inputs for a biomaRt query. For example, if we want to retrieve all EntrezGene identifiers on chromosome X, chromosome will be the filter, with corresponding value X.

1 2	listFilters(mart, what = c("name", "description")) searchFilters(mart, pattern)

`mart`	object of class `Mart` created using the `useMart` function
`what`	character vector indicating what information to display about the available filters. Valid values are `name`, `description`, `options`, `fullDescription`, `filters`, `type`, `operation`, `filters8`, `filters9`.
`pattern`	Character vector defining the regular expression (`regex)` to be used for the search. If left blank the default is to use ".*" which will match everything.

Steffen Durinck, Mike Smith

if(interactive()){

    ## list the available Ensembl marts and use Ensembl Genes
    listEnsembl()
    ensembl <- useEnsembl(biomart = "ensembl", dataset = 'hsapiens_gene_ensembl')

    ## list the available datasets in this Mart
    listFilters(mart = ensembl)

    ## the list of filters is long and not easy to read
    ## we can search for a term of interest to reduce this e.g. 'gene'
    searchFilters(mart = ensembl, pattern = "gene")
    
    ## search the available filters to find entries containing 'entrez' or 'hgnc'
    searchFilters(mart = ensembl, 'entrez|hgnc') 
}