# Extracting Rows of a Matrix

210 visualizzazioni (ultimi 30 giorni)
A M il 27 Mar 2017
Commentato: Star Strider il 13 Feb 2024
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
##### 1 CommentoMostra -1 commenti meno recentiNascondi -1 commenti meno recenti
SURESH KUMAR il 6 Apr 2023
very simple
Please follow this step
Matrix_Column= A(1:4,:);

Accedi per commentare.

### Risposta accettata

Star Strider il 27 Mar 2017
First_Four_Rows = A(1:4,:);
##### 4 CommentiMostra 2 commenti meno recentiNascondi 2 commenti meno recenti
A M il 27 Mar 2017
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 il 28 Mar 2017
No worries. I needed to understand what you want.
This works:
Extracted = A((A(:,1)>99) & (A(:,1)<140),:);

Accedi per commentare.

### Più risposte (2)

John BG il 27 Mar 2017
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
##### 1 CommentoMostra -1 commenti meno recentiNascondi -1 commenti meno recenti
Jan il 28 Mar 2017
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.

Accedi per commentare.

Maryam il 13 Feb 2024
how we display only 2nd and 5th row of matrix T in matrix X in matlab
##### 1 CommentoMostra -1 commenti meno recentiNascondi -1 commenti meno recenti
Star Strider il 13 Feb 2024
X_2_5 = X([2 5],:)
.

Accedi per commentare.

### Categorie

Scopri di più su Logical in Help Center e File Exchange

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by