Duplicate a matrix using nested for loops
1 Ansicht (letzte 30 Tage)
Ältere Kommentare anzeigen
Tyler M
am 20 Feb. 2018
Kommentiert: Stephen23
am 20 Feb. 2018
In Matlab I have been trying to duplicate matrix A [2,4,1;6,7,2;3,5,9] to matrix B using nested for loops. I know the general format uses an algorithm within the loop ie.
m=3
n=3
b=zeros(m,n)
for i=1:m
for j=1:n
B(m,n)= *algorithm here*
end
end
I can not find an algorithm that would work for this matrix and I believe that it was designed this way on purpose. I have tried pulling numbers out of matrix A using
A=[2,4,1;6,7,2;3,5,9]
for c=A(1,:)
for d=A(2,:)
for e=A(3,:)
end
end
end
B=[c;d;e]
but this just assigns the values for the last column of A to a 1x3 matrix B (B=[1;2;9]
I have also tried scouring the www for help with how to duplicated a matrix that is not algorithmic using nested for loops to no avail.
Any help or guidance would be much appreciated.
1 Kommentar
Akzeptierte Antwort
Roger Stafford
am 20 Feb. 2018
What's wrong with
B = A; % ?
However, if you absolutely must do it with nested for-loops then do:
[m,n] = size(A);
B = zeros(m,n);
for i1 = 1:m
for i2 = 1:n
B(i1,i2) = A(i1,i2);
end
end
_
3 Kommentare
Roger Stafford
am 20 Feb. 2018
Bearbeitet: Roger Stafford
am 20 Feb. 2018
You wouldn't want to use just B=A inside those for-loops. That would be extremely wasteful of computing time. B=A by itself does the job without for-loops. Using for-loops with B(i1,i2) = A(i1,i2); is bad enough.
Weitere Antworten (0)
Siehe auch
Kategorien
Mehr zu Loops and Conditional Statements finden Sie in Help Center und File Exchange
Produkte
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!