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;
    about (true)
    {
    console.writeline ("input a");
    = console.readline ();
    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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