estimateSd() does not check for sufficient number of finite data point

[HenrikBengtsson]

I got:

> fit <- c3co::segmentData(dat, stat = "TCN")
Error in Y[-c(n - 2, n - 1, n), , drop = FALSE] : subscript out of bounds

which happens in estimateSd():

> traceback()
8: estimateSd(Y)
7: sweep(Y, MARGIN = 2, STATS = estimateSd(Y), FUN = "/")
6: segmentByRBS(Y, K, ...)
5: segFUN(Yseg, ...)
4: eval(expr)
3: prof(segFUN(Yseg, ...), doit = profile)
2: jointSeg(Y = dataToSeg[ww, ], method = "RBS", K = 100, modelSelectionMethod = "Birge")
1: segmentData(dat2, stat = "TCN")

Troubleshooting

This is because estimateSd() assumes there are enough number of data points;

> print(estimateSd)
function (y, method = c("Hall", "von Neumann")) 
{
    method <- match.arg(method)
    if (method == "von Neumann") {
        y <- stats::na.omit(y)
        dy <- diff(y)
        Sd <- stats::mad(dy)/sqrt(2)
    }
    else if (method == "Hall") {
        Y <- as.matrix(y)
        n <- nrow(Y)
        wei <- c(0.1942, 0.2809, 0.3832, -0.8582)
        Y1 <- Y[-c(n - 2, n - 1, n), , drop = FALSE] * wei[1]
        Y2 <- Y[-c(1, n - 1, n), , drop = FALSE] * wei[2]
        Y3 <- Y[-c(1, 2, n), , drop = FALSE] * wei[3]
        Y4 <- Y[-c(1, 2, 3), , drop = FALSE] * wei[4]
        Sd <- sqrt(colMeans((Y1 + Y2 + Y3 + Y4)^2, na.rm = TRUE))
    }
    return(Sd)
}
<environment: namespace:jointseg>

Suggestion

Return NA_real_ whenever n <= 2 (or give an informative error message).