1 files changed, 5 insertions, 5 deletions
diff --git a/matrix.lua b/matrix.lua
index 2a70590..7aa1f12 100644
--- a/matrix.lua
+++ b/matrix.lua
@@ -2,14 +2,14 @@ function nerv.FloatMatrix:__tostring__()
     local ncol = self:ncol()
     local nrow = self:nrow()
     local i = 0
-    local res = ""
+    local strt = {}
     for row = 0, nrow - 1 do
         for col = 0, ncol - 1 do
-            res = res .. string.format("%f ", self:get_elem(i))
+            table.insert(strt, string.format("%f ", self:get_elem(i)))
             i = i + 1
         end
-        res = res .. "\n"
+        table.insert(strt, "\n")
     end
-    res = res .. string.format("[Float Matrix %d x %d]", nrow, ncol)
-    return res
+    table.insert(strt, string.format("[Float Matrix %d x %d]", nrow, ncol))
+    return table.concat(strt)
 end