Tolerance check of absolute value in 'matrix_eq'

2 files changed, 3 insertions, 1 deletions

diff --git a/matrix.c b/matrix.c
index 46302f7..1e1a4dd 100644
--- a/matrix.c
+++ b/matrix.c
@@ -247,7 +247,7 @@ int matrix_eq(const Matrix *A, const Matrix *B, const double tol)
     for (size_t i = 0; i < A->m; ++i)
     {
         for (size_t j = 0; j < A->n; ++j)
-            if (matrix_at(A, i, j) - matrix_at(B, i, j) > tol) return FALSE;   
+            if (ABS(matrix_at(A, i, j) - matrix_at(B, i, j)) > tol) return FALSE;
     }
     return TRUE;
 }
diff --git a/utils.h b/utils.h
index 8503c1b..8aecde3 100644
--- a/utils.h
+++ b/utils.h
@@ -1,6 +1,8 @@
 #ifndef UTIL_H
 #define UTIL_H
 
+#define ABS(x) ((x) >= 0 ? (x) : -(x))
+
 char *str_delete_at(const char *str, const int pos);
 size_t str_count_occ(const char *str, const char ch);