R/cumsum_with_reset.R

In kristian-bak/betting: An Amazing Shiny App

#' Cumsum with reset
#' @param x numeric vector
#' @param reset integer specifying reset value (default is zero)
#' @return numeric vector of same length as x
#' 
cumsum_with_reset <- function(x, reset = 0) {
  
  n <- length(x)
  x[is.na(x)] <- 0
  y <- rep(NA, n)
  if (x[1] != reset) {
    y[1] <- x[1]
  } else {
    y[1] <- 0
  }
  
  if (length(x) > 1) {
    for (i in 2:n) {
      if (x[i] != reset) {
        if (x[i - 1] != reset) {
          y[i] <- y[i - 1] + x[i]
        } else {
          y[i] <- x[i]
        }
      } else {
        y[i] <- 0
      }
    }
  }

  return(y)
}