MATLAB: Creating matric of multiple arrays

arrayscreating matricesMATLAB

x=0:12;

k=5;

a=k+x;

b=k+2x;

c=k+4x;

d=kx;

I'd like to create 2*2 matrix of four arrays (a,b,c,d).

Z=[a b; c d];

How could I realize this task by using for loop? Or do you have any other way to realize it? I ask for your advice! Thank you in advance!

Best Answer

You should be able to accomplish what you're looking for with some matrix indexing, no loop necessary.

x = 1:100;
k = 12;
a = x + k; % Makes a 100x1 size array, 13:112
b = 2*x + k; % Makes a 100x1 size array following the same formula
c = 4*x + k;
d = x * k;
% Adding a third dimension of Z allows you to basically stack each of the elements of a, b, c, and d
% into the one 2x2 format. Z(:,:,1) is a 2x2 of [a(1), b(1); c(1), d(1)], and each subsequent 'sheet'
% takes you to the next set of elements in the four matrices.
Z(1,1,:) = a;
Z(1,2,:) = b;
Z(2,1,:) = c;
Z(2,2,:) = d;

Related Solutions

MATLAB: Problem when plotting a graph after for and if else if

It's because of the way you set up your if statement. You're comparing the whole x to t so you're getting a logical vector and then you're basically saying if vector. You should either vectorize the indexes, or use a for look like this:

C = 100;
g = 20;
s = 0.5;
T = 1;
t = 0.68;
x = 0:0.1:1
for k = 1 : length(x)
	if x(k) < t
		d(k) = 32 ./ (1 - x(k) * 0.2);
		fprintf('For k = %d, x(k) = %.1f, and d(k) = %.1f.  x is less than t.\n', k, x(k), d(k));
	else
		d(k) = C*(1-g/C)^2./(2*(1.-x(k)*g/C))+900*T*((x(k)-1.)+sqrt((x(k)-1).^2+12*C*(x(k)-t)./(T*s*g*3600)));
		fprintf('For k = %d, x(k) = %.1f, and d(k) = %.1f.  x is greater than t.\n', k, x(k), d(k));
	end
end
plot(x, d, 'b.-', 'MarkerSize', 20)
grid on;
d

Here is the vectorized version:

C = 100;
g = 20;
s = 0.5;
T = 1;
t = 0.68;
x = 0:0.1:1
% Initialize all elements to this equation.
d = C*(1-g/C)^2./(2*(1.-x*g/C))+900*T*((x-1.)+sqrt((x-1).^2+12*C*(x-t)./(T*s*g*3600)));
% Now handle case there x is less than t.
indexes = x < t
d(indexes) = 32 ./ (1 - x(indexes) * 0.2);
plot(x, d, 'b.-', 'MarkerSize', 20)
grid on;
d

MATLAB: Hi. I am trying to create a loop to multiply two matricies 40 times such that BC=D1 and CD1=D2 and B*D2=D3 and so on . I am very much new to matlab. Can anyone help me on this

Try this:

clc;
b = randi(9, 2, 2)
c = randi(9, 2, 2)
D{1} = b * c;
for k = 2 : 5 % End wherever you want
  theRemainder = rem(k, 2);
  % Alternate multiplying by b or c
  if theRemainder == 0
    D{k} = c * D{k-1};
  else
    D{k} = b * D{k-1};
  end
end
celldisp(D);

Best Answer

Related Solutions

MATLAB: Problem when plotting a graph after for and if else if

MATLAB: Hi. I am trying to create a loop to multiply two matricies 40 times such that B*C=D1 and C*D1=D2 and B*D2=D3 and so on . I am very much new to matlab. Can anyone help me on this

Related Question

MATLAB: Hi. I am trying to create a loop to multiply two matricies 40 times such that BC=D1 and CD1=D2 and B*D2=D3 and so on . I am very much new to matlab. Can anyone help me on this