Extracting Rows of a Matrix

I have a matrix 'A' of size 8*5. How to extract the first 4 rows of this Matrix.

 A =  90.6848   72.5836   54.4646   36.3276   18.1728
      99.7018   79.8089   59.8924   39.9521   19.9880
     110.7026   88.6271   66.5192   44.3788   22.2058
     124.4195   99.6278   74.7902   49.9066   24.9766
     141.9931  113.7314   85.4017   57.0036   28.5365
     165.3005  132.4561   99.5049   66.4459   33.2780
     197.6559  158.4928  119.1482   79.6196   39.9045
     245.4805  197.0868  148.3494   99.2610   49.8139

[SURESH KUMAR]

very simple

Please follow this step

Matrix_Column= A(1:4,:);

Answer 1

[Star Strider]

First_Four_Rows = A(1:4,:);

[A M]

and if i want to set limit for the extraction of values of this matrix rows... like extract rows whose first value is greater than 99 and less than 40. How to approach that?

[Star Strider]

Please clarify what you want.

No one value can be both ‘greater than 99 and less than 40’. That is logically impossible.

[A M]

Sorry for the confusion. Like all those rows whose first value is greater than 99 and less than 140, i.e. rows 2, 3 and 4

[Star Strider]

No worries. I needed to understand what you want.

This works:

Extracted = A((A(:,1)>99) & (A(:,1)<140),:);

Answer 2

[John BG]

With

A(1:4,:)

you still get a 2D matrix as result

If you want to pull elements and get a 1D vector then

A([1:4 1:end])

same elements, lined up, 4x5 now 1x44

if you find these lines useful would you please mark my answer as Accepted Answer?

To any other reader, if you find this answer of any help, please click on the thumbs-up vote link,

thanks in advance for time and attention

John BG

<mailto:[e-mail] [e-mail]>

[Jan]

If the original matrix has the dimension [8 x 5] and A M wants to extract 4 rows, how could the result be a [1 x 44] vector? Your "1:end" means "1:numel(A)" here and is not useful.

Answer 3

[Maryam]

how we display only 2nd and 5th row of matrix T in matrix X in matlab

[Star Strider]

X_2_5 = X([2 5],:)

.