@@ -420,7 +420,7 @@ make_comb_mat = function(..., mode = c("distinct", "intersect", "union"),

 	mode = match.arg(mode)[1]

 	if(length(lt) == 1) {

 		lt = lt[[1]]

-		if(!is.null(dim(lt))) {

+		if(length(dim(lt)) == 2) { # a matrix

 			m = make_comb_mat_from_matrix(lt, mode = mode, top_n_sets = top_n_sets, 

 				min_set_size = min_set_size, universal_set = universal_set, complement_size = complement_size)

 			if(remove_empty_comb_set) {

@@ -512,6 +512,7 @@ set_size = function(m) {

 #

 # == param

 # -m A combination matrix returned by `make_comb_mat`.

+# -degree degree of the intersection. The value can be a vector.

 #

 # == value

 # A vector of sizes of the combination sets.

@@ -523,8 +524,13 @@ set_size = function(m) {

 #           c = sample(letters, 20))

 # m = make_comb_mat(lt)

 # comb_size(m)

-comb_size = function(m) {

-	structure(attr(m, "comb_size"), names = comb_name(m))

+comb_size = function(m, degree = NULL) {

+	x = structure(attr(m, "comb_size"), names = comb_name(m))

+	if(is.null(degree)) {

+		return(x)

+	} else {

+		x[comb_degree(m) %in% degree]

+	}

 }

 # == title