R/grid.on.R

In AnalyzeTS: Analyze Fuzzy Time Series

grid.on <-
function (h = TRUE, v = TRUE, col = "gray", nv = 1, nh = 1, lty = 3) 
{
    is.wholenumber <- function(x, tol = .Machine$double.eps^0.5) abs(x - 
        round(x)) < tol
    if (!is.wholenumber(nh)) 
        stop("Error in 'nh'!")
    if (!is.wholenumber(nv)) 
        stop("Error in 'nv'!")
    ve <- par()
    n.col <- ve$xaxp
    n.row <- ve$yaxp
    if (h == TRUE) {
        for (i in -nh:(nh * n.row[3] + nh)) abline(h = n.row[1] + 
            i * ((n.row[2] - n.row[1])/(n.row[3] * nh)), col = col, 
            lty = lty)
    }
    if (v == TRUE) {
        for (i in -nv:(nv * n.col[3] + nv)) abline(v = n.col[1] + 
            i * ((n.col[2] - n.col[1])/(n.col[3] * nv)), col = col, 
            lty = lty)
    }
}