Hi all,
I'm a newbiew to this forum. I encountered a problem when using the function rmatrixsolvels to solve a overdetermined A*x = b problem.
The purpose is solving two unknowns, u1 and u2. The equation is as this format G = u1 * P / (P + u2). G and P are both observed from real experiments. The equation above can be transformed into two different formats as below. Format 1 P * u1  p * u2 = G * P Format 2 p * 1 / u1 + u2 / u1 = P / G. In Format 2, I set 1 / u1 as x1, and u2 / u1 as x2, so for A*x = b, the equation is like G * x1 + x2 = P/G Clearly, A[i, 0] = Gi, A[i, 1] = 1; b[i] = Pi/Gi, i = 1,2,..,m data points Then I used rmatrixsolvels to solve the problem and got the exact answers I want.
However, if I follow Format 1, A[i, 0] = Pi, A[i, 1] = Gi; b[i] = Gi * Pi, Then I used rmatrixsolvels and got totally different answers!
I'm wondering when we use rmatrixsolvels, should one column in matrix A be always 1? Is that why my Format 2 failed? Per my poor knowledge on leastsquare method, the equation is x0 + x1*t1 + x2* t2 .... = y. Does that mean the coefficient for x0, is 1 by default? It may be more like a math rather than coding quesiton. Any comments appreciated!
