@@ -361,7 +361,11 @@ setMethod("colWeightedMads", signature(x = "dgCMatrix"),

     }

     setNames(reduce_sparse_matrix_to_num(x, function(values, row_indices, number_of_zeros){

       if(length(values) == 0){

-        0.0

+        if(number_of_zeros > 0){

+          0

+        }else{

+          NA_real_

+        }

       }else{

         new_vec <- c(0, values)

         zero_weight <- sum(w[-(row_indices + 1)])

@@ -291,6 +291,13 @@ for(idx in seq_along(matrix_list)){

   test_that("colWeightedMads works", {

+    expect_equal(colWeightedMads(sp_mat), matrixStats::colWeightedMads(mat))

+    expect_equal(colWeightedMads(sp_mat, na.rm=TRUE), matrixStats::colWeightedMads(mat, na.rm=TRUE))

+

+    weights <- rep(1, nrow(sp_mat))

+    expect_equal(colWeightedMads(sp_mat, w=weights), matrixStats::colWeightedMads(mat, w=weights))

+    expect_equal(colWeightedMads(sp_mat, na.rm=TRUE, w=weights), matrixStats::colWeightedMads(mat, w=weights, na.rm=TRUE))

+

     # Test check for length of w

     expect_error(colWeightedMeans(sp_mat, w=1:42))

     expect_error(matrixStats::colWeightedMeans(mat, w=1:42))