this is a pretty strange result.

the number displayed seems to be ok.

but with equal operation,it returns false.

i don't know what is going on here.need some help.

#include <stdio.h>
#include <d3dx9.h>

int main()
{
	D3DXMATRIX m1,m2,m3,m4;
	D3DXMatrixRotationY(&m1,0.1f);
	D3DXMatrixRotationY(&m2,0.1f);
	m3=m1*m2;
	D3DXMatrixRotationY(&m4,0.2f);

	for(int i=0; i<4; ++i)
	{
		for(int j = 0; j<4; ++j)
		{
			if(m3(i, j) == m4(i, j))
			{
				printf("(%d,%d) equal\n",i,j);
			}
			else
			{
				printf("(%d,%d) not equal!!!!\n",i,j);
				printf("(m3 = %f, m4 = %f) not equal!!!!\n",m3(i,j),m4(i,j));
			}
		}
	}

	return 0;
}

console result

(0,0) equal
(0,1) equal
(0,2) not equal!!!!
(m3 = -0.198669, m4 = -0.198669) not equal!!!!
(0,3) equal
(1,0) equal
(1,1) equal
(1,2) equal
(1,3) equal
(2,0) not equal!!!!
(m3 = 0.198669, m4 = 0.198669) not equal!!!!
(2,1) equal
(2,2) equal
(2,3) equal
(3,0) equal
(3,1) equal
(3,2) equal
(3,3) equal

thank you,and i should read some c language book,i really don't know %1.8e format which did confuse me.