aa_card.Rd
Stratified estimation of Accuracy and Area. The stratified estimator accounts for disproportional allocation of samples within the strata.
aa_card(
data,
w = NULL,
strata = NULL,
area = NULL,
confusion_matrix = T,
olofsson = T
)
confusion matrix or cbind(reference,map)
stratum weights
stratum names
total area (optional)
(default=T) define if data contains a confusion matrix or sample vectors
(default=TRUE) uses Olofsson formula instead of Card to estimate standard errors of reference class proportions and OA.
list of accuracy and area proportion estimates and associated standard errors
Map agreement
Card, D.H. (1982). Using Known Map Category Marginal Frequencies to Improve Estimates of Thematic Map Accuracy. Photogrammetric Engineering and Remote Sensing, 48, 431-439
Olofsson, P., Foody, G.M., Stehman, S.V., & Woodcock, C.E. (2013). Making better use of accuracy data in land change studies: Estimating accuracy and area and quantifying uncertainty using stratified estimation. Remote Sensing of Environment, 129, 122-131
m <- matrix(c(410,67,26,369), nrow=2)
A <- c(828837,33067283)
w_j <- A/sum(A)
aa_card(m, w_j)
#> $cm
#> [,1] [,2]
#> [1,] 410 26
#> [2,] 67 369
#>
#> $cmp
#> 1 2
#> 1 0.0229941 0.001458163
#> 2 0.1499122 0.825635581
#>
#> $stats
#> class ua pa p_i p_i_se ua_se pa_se
#> 1 1 0.9403670 0.132986 0.1729063 0.01687046 0.01134094 0.0130331827
#> 2 2 0.8463303 0.998237 0.8270937 0.01687046 0.01727113 0.0003366146
#> w
#> 1 0.02445227
#> 2 0.97554773
#>
#> $accuracy
#> [1] 0.84862969 0.01687046
#>
#> $area
#> class proportion proportion_ci
#> 1 1 0.1729063 0.03306609
#> 2 2 0.8270937 0.03306609
#>