added some asserts and made minor api changes

lina.h

@@ -1,16 +1,16 @@
 
 // Evaluate the dot product C = A*B where C is of size m by l, A is m by n and B is n by l.
 // NOTE: C can't be the same pointer of A or B.
-void lina_dot(double **A, double **B, double **C, unsigned int m, unsigned int n, unsigned int l);
+void lina_dot(double *A, double *B, double *C, int m, int n, int l);
 
 // Evaluate C = A + B where A,B,C are m by n.
 // NOTE: C can be the same location of A or B.
-void lina_add(double **A, double **B, double **C, unsigned int m, unsigned int n);
+void lina_add(double *A, double *B, double *C, int m, int n);
 
 // Evaluate B = k*A where A and B are m by n matrices.
 // NOTE: B can be the same location of A.
-void lina_scale(double **A, double **B, double k, unsigned int m, unsigned int n);
+void lina_scale(double *A, double *B, double k, int m, int n);
 
 // Evaluate B = A^t (the transpose of A) where A is m by n.
 // NOTE: B can be the same location of A.
-void lina_transpose(double **A, double **B, unsigned int m, unsigned int n);
+void lina_transpose(double *A, double *B, int m, int n);