# Matlab Matrix (matrix) problem

### 2 thoughts on “Matlab Matrix (matrix) problem”

1. The matrix of 5*5, then the input range is 0 ~ 4
private static void main (string [] args)
{
string A;
string b;
{
console.writeline ("input a");
console.writeline ("input B"); r n b = console.readline ();
if (ISVALID (a)

2. The/incomplete matrix removal in matlab.
You can use Help Mrdivide to see/help:
>> help mrdivide

/Slash or Right Matrix Divide.
a/b is the matrix division of. B into a, which is roughly the
same as a*inv (b), except it is computed in a different way.
more precisly, a/b = (ba).

M/b can be roughly regarded as A*INV (b), but it is another method. More precisely a/b = (ba).

then look at what Dongdong is.
>> Help MLDIVIDE

backslash or left matrix divide.
ab is the matrix division of a Into b, white is roughly the
said as inv (A) (A) *B, Except it is computed in a different way.
if a is an n-by-n matrix and b is a color with n
, or a matrix with sectral color, then r. n x = AB is the solution to the equation a*x = b compute by
gsesian. A warning message is printed if a is n badly scaled or nearly singular. Aeye (A)) The
inverse of a.

if a is an m-by-n matrix with m u003Cor> n and b is a colorn
vector with m, or a matrix with Several Such color,
the x = ab is the solution in the least squares sense to the
under-or system of equations a*x = b. the n effective rank, k, of a is from the qr
with pivoting. a solution x is computed which has at most k
nonzero per colleumn. If k u003Cn this will usually not n be the saMe solution as pinvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv *B. Aeye ( SIZE (a)) Process A
inverse of a.

is to say that when A is a column vector of n lines n lines n lines, x = ab is the linear equation group A* X = B's solution, the algorithm is to eliminate the method with Gauss. Aeye (SIZE (a)) produces the counter -matrix of the square array A.

. If A is the matrix of M*n and m ≠ n, B is the same column vector of the same number (M line) of row (M line), x = ab is a non -ranking linear equation group A*x = B's solution, A's rank K is decomposed by QR. If K u003Cn usually results from PINV (A)*B (PINV (A) is a general reverse matrix of A). Aeye (SIZE (a)) gets a broad tactical matrix of A.

In short, AB is the solution of A*x = b. You can see it as a reverse matrix of A, but it is just a broad and reverse matrix, so that A is not a square matrix.

. As for A/B, use less in the linear equation group. Because B is usually written as a column vector, it is enough to use reaction. In/if/B is usually a row vector.
This can be regarded as the solution of X*A = b, and the number of columns of B here is equal to the number of A.

ab = pinv (a)*b
a/b = a*pinv (b)

For example:
>> a = pascal ( 3) %a assignment is a square matrix of 3*3.

a =

1 1
3
1 3 6

>> [1: 3 ] % b is the column vector of 3*1.

B =

1
2
3

>> x = a % to seek AX = b The solution, the result x is a column vector, note that A is not BA

x =

0
0

>> a*x % Verify A*x just equal to B

Aans =

1
3

>> x = b/a % is except this time, but B is the line vector, A is also poured, it is B/A when it is removed, not A/B, the result X is a line vector

x =

0

>> x*a % to verify it, the same as B.

ANS =

1 2 3

>> a = rand (3,4) % of this time, A is not a square matrix,是3*4的矩阵rnrnA =rnrn 0.5298 0.3798 0.4611 0.0592rn 0.6405 0.7833 0.5678 0.6029rn 0.2091 0.6808 0.7942 0.0503rnr n >> x = A % The actual group does not have the only solution, but countless solutions, so the solution is a special solution
nx =
n -1.5132
4.9856
0
-1.5528

>> a*x % to verify, equal to B.

ANS =

1.0000
2.0000
3.0000

>> a = rand (3,2) % look at it again The matrix of 3*2, the number of rows> columns

a =

0.4154 0.0150
0.3050 0.7680
0.8744 0.9708

>> x = a

x =

1.8603
1.5902

>> a*x % to verify it, eh? Why is it not equal to B?

ANS =

0.7966
1.7886
3.1704

Because the number of equations (number of rows) is too large, the number of unknown (column) is too small, 2 unknown numbers, you can find the solution with 2 linear unrelated equations. Now there are many equations. So there is actually no solution, but Matlab uses a minimum dharma in the sense of approximate solution, so it ranges when verification, but it is as close as possible to meet all equations as much as possible.

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