Add convenience function for conversion to ipm
Change-Id: I2b9138322558fc1a2da2f9877cefe3d2268d2412
diff --git a/R/misc.R b/R/misc.R
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+
+#' Convert corpus frequency table to instances per million.
+#'
+#' Convenience function for converting frequency tables to instances per
+#' million.
+#'
+#' Given a table with columns \code{f}, \code{conf.low}, and \code{conf.high}, \code{ipm} ads a \code{column ipm}
+#' und multiplies conf.low and \code{conf.high} with 10^6.
+#'
+#' @param df table returned from \code{\link{frequencyQuery}}
+#'
+#' @return original table with additional column \code{ipm} and converted columns \code{conf.low} and \code{conf.high}
+#' @export
+#'
+#' @importFrom dplyr .data
+#'
+#' @examples
+#' new("KorAPConnection") %>% frequencyQuery("Test", paste0("pubDate in ", 2000:2002)) %>% ipm()
+ipm <- function(df) {
+ df %>%
+ mutate(ipm = .data$f * 10^6, conf.low = .data$conf.low * 10^6, conf.high = .data$conf.high * 10^6)
+}
+
+