Add fingerprintOPT, fingerprintNLS, and lwRegcov.lam

.Rbuildignore

@@ -12,4 +12,7 @@
 ^NEWS\.md$
 ^README\.md$
 ^notes$
-^cran-comments\.md$
+^cran-comments\.md$
+^\.claude$
+^proposed_changes$                                                                                                                                
+^STUDY_GUIDE

DESCRIPTION

@@ -1,13 +1,14 @@
 Package: dacc
 Title: Detection and Attribution Analysis of Climate Change
-Version: 0.0-8
-Date: 2025-12-05
+Version: 0.0-10
+Date: 2026-03-25
 Authors@R: c(
     person(given = "Yan", family = "Li",
            email = "yan.4.li@uconn.edu",
            role = c("aut", "cre")),
     person(given = "Kun", family = "Chen", role = "aut"),
-    person(given = "Jun", family = "Yan", role = "aut"))
+    person(given = "Jun", family = "Yan", role = "aut"),
+    person(given = "Charles", family = "Benfer", role = "aut"))
 Description: 
     Detection and attribution of climate change using methods including optimal fingerprinting via 
     generalized total least squares or an estimating equation approach (Li et al., 2025, 

NAMESPACE

@@ -2,6 +2,8 @@
 
 export(Covest)
 export(fingerprint)
+export(fingerprintNLS)
+export(fingerprintOPT)
 export(fpPrep)
 import(magrittr)
 import(ncdf4)
@@ -16,6 +18,7 @@ importFrom(pracma,ceil)
 importFrom(sp,point.in.polygon)
 importFrom(stats,cov)
 importFrom(stats,pnorm)
+importFrom(stats,qchisq)
 importFrom(stats,qnorm)
 importFrom(stats,quantile)
 importFrom(stats,sd)

R/Covest.R

@@ -134,7 +134,22 @@ lwRegcov <- function(Z) {
   b2 * m / d2 * Ip + a2 / d2 * sample.cov
 }
 
-
+lwRegcov.lam <- function(Z) {
+  n <- nrow(Z)
+  p <- ncol(Z)
+  sample.cov <- cov(Z)
+  Ip <- diag(p)
+  m  <- sum(diag(sample.cov %*% Ip)) / p
+  Zp <- sample.cov - m * Ip
+  d2 <- sum(diag(Zp %*% t(Zp))) / p
+  bt <- (diag(Z %*% t(Z))^2 -
+           2 * diag(Z %*% sample.cov %*% t(Z)) +
+           rep(1, n) * sum(diag(sample.cov %*% sample.cov))) / p
+  bb2 <- 1 / n^2 * sum(bt)
+  b2  <- min(bb2, d2)
+  a2  <- d2 - b2
+  b2 * m / a2
+}