how to Invert a matrix and how to delete a row and a column?

1.4286 5.0000 Inf 5.0000 3.3333 Inf

5.0000 0.9524 4.0000 10.0000 3.3333 5.0000

Inf 4.0000 1.6393 Inf 3.8462 10.0000

5.0000 10.0000 Inf 1.4286 2.5000 Inf

3.3333 3.3333 3.8462 2.5000 0.6410 3.3333

Inf 5.0000 10.0000 Inf 3.3333 1.6667

I have this matrix but since it contains inf variable i cant invert the matrix....and i get this NaN .....(can i replace inf with zero?)

and how can i delete specific column and row?....

Answer 1

[John D'Errico]

You would need to delete almost every row and column. What does it mean to invert a matrix of arbittraily small size then?

And replacing inf with zero is totally inconsistent with what that element was originally, so just repacing infs with zero and still computing an inverse seems wrong. An inf is a immensely large number, as opposed to a really tiny number.

Can you replace an inf with zero? Well, trivially, yes. Read the help for isinf to learn how to locate inf elements.

help isinf

 ISINF  True for infinite elements.
    ISINF(X) returns an array that contains 1's where the
    elements of X are +Inf or -Inf and 0's where they are not.
    For example, ISINF([pi NaN Inf -Inf]) is [0 0 1 1].
 
    See also ISFINITE, ISNAN.

    Documentation for isinf
       doc isinf

    Other functions named isinf

       calendarDuration/isinf    dlarray/isinf     iddata/isinf
       codistributed/isinf       duration/isinf    sym/isinf
       datetime/isinf            gpuArray/isinf

Can you delete a row or column of a matrix again, trivially easy. (Should you be reading one of the many MATLAB turorials to be found? Reading the manual is a good thing. Even real men do it.)

A = magic(3)

A = 3×3

8 1 6 3 5 7 4 9 2

A(2,:) = []

A = 2×3

8 1 6 4 9 2

[arian hoseini]

so since im not a "real man" thank u.