R/nhs_search.R

In yikeshu0611/nhanesR: Tools for "NHANES" Database

#' search in "NHANES" database
#'
#' @param ... one or more keywords, use look() function to search.
#' @param cat logical. whether to show results number
#' @return a dataframe
#' @export
#'
#' @examples
#' # x <- nhs_search('diabetes')
nhs_search <- function(...,cat=TRUE,fileds=NULL){
    key <- c(...)
    vartext <- paste0(get_config_path(),'/varLabel.txt')
    if (!file.exists(vartext)) build_varLabel() # build
    varLabel <- data.table::fread(vartext,data.table = FALSE)
    if (is.null(key)) return(varLabel)
    if (is.null(fileds)){
        fileds <- set::not(colnames(varLabel),'url')
    }else{
        ck <- sapply(set::not(colnames(varLabel),'url'), function(i) any(sapply(fileds, function(j) do::left_equal(i,j))))
        fileds <- colnames(varLabel)[ck]
    }
    index <- paste0_columns(varLabel[,fileds,drop=FALSE],'------')
    ck <- lookl(index,tolower(key),ignore.case = TRUE)
    df <- varLabel[ck,]
    if (nrow(df)==0){
        cat('results: ',nrow(df))
        return()
    }
    nchar <- df
    for (i in 1:ncol(df)) {
        for (j in 1:nrow(df)) {
            nchar[j,i] <- tryCatch(nchar(df[j,i]),error=function(e) 1)
        }
        nchar[,i] <- as.numeric(nchar[,i])
    }
    if (is.data.frame(nchar) | is.matrix(nchar)){
        df <- df[, nchar |> colSums() > 0,drop=FALSE]
    }else{
        df <- df[, nchar > 0,drop=FALSE]
    }
    class(df) <- c('nhs_search','data.frame')
    if (cat) cat('results: ',nrow(df))
    keys <- strsplit(key,'\\|') |> unlist() |> unique() |> do::Trim_left(c(' ','~','!','=')) |> unique()
    attr(df,'nhs_search') <- keys
    df
}