Why can't I concatenate simple matrix? vertcat Dimensions of matrices being concatenated are not consistent

I have the following 'simple' code whereby I make 6 complex numbers which are defined by a vector. I then want to stack these numbers in a matrix. It seems to me that if I define each number as a variable I can simply stack the variable in matrix C but if I try and just directly input them from a calculation then I can't stack the numbers:

      clear
      A = [1,2,3,4,5,6];
      x = 2;

      w0 = 2*pi*67*10^9;

      wj = 2*pi*86*10^9;

      wp = 2*pi*12*10^9;

      maxBeta = 0.45;

      wsfac = 0.6;
      wifac = 1-wsfac;
      ws = wsfac*wp;
              wi = wifac*wp;
              wshg = 2*wp;
              wps = wp+ws;
              wpi = wp+wi;
              Ap0 = 0.5*w0/wp;
              As0 = Ap0*sqrt(0.0057*wp/ws);
              Ashg0 = 0;
              Aps = 0;
              Spi = 0;
              kp = (wp/w0)*(1/(sqrt(1-(wp/wj)^2)));
              ks = (ws/w0)*(1/(sqrt(1-(ws/wj)^2)));
              ki = (wi/w0)*(1/(sqrt(1-(wi/wj)^2)));
              kshg = (wshg/w0)*(1/(sqrt(1-(wshg/wj)^2)));
              kps = (wps/w0)*(1/(sqrt(1-(wps/wj)^2)));
              kpi = (wpi/w0)*(1/(sqrt(1-(wpi/wj)^2)));

              delk = 3*ws*wi*wp/(2*w0*(wj^2));

              modk = sqrt(wp*Ap0^2/(ws*As0^2+wp*Ap0^2));

              dp = -(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x)+(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x)+(maxBeta/2)*kps*ks*A(5)*conj(A(2))*exp(1i*(kps-ks-kp)*x)+(maxBeta/2)*kpi*ki*A(6)*conj(A(3))*exp(1i*(kpi-ki-kp)*x);
              ds = (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kps*conj(A(1))*A(5)*exp(1i*(kps-kp-ks)*x)+(maxBeta/2)*kshg*kps*conj(A(5))*A(4)*exp(1i*(kshg-kps-ks)*x);
              di = (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kpi*conj(A(1))*A(6)*exp(1i*(kpi-kp-ki)*x)+(maxBeta/2)*kshg*kpi*conj(A(6))*A(4)*exp(1i*(kshg-kpi-ki)*x);
              dshg = -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)-(maxBeta/2)*ki*kps*A(3)*A(5)*exp(1i*(ki+kps-kshg)*x) -(maxBeta/2)*kpi*ks*A(6)*A(2)*exp(1i*(kpi+ks-kshg)*x);
              dps = -(maxBeta/2)*kp*ks*A(1)*A(2)*exp(1i*(kp+ks-kps)*x)+(maxBeta/2)*ki*kshg*conj(A(3))*A(4)*exp(1i*(kshg-ki-kps)*x);
              dpi = -(maxBeta/2)*kp*ki*A(1)*A(3)*exp(1i*(kp+ki-kpi)*x)+(maxBeta/2)*ks*kshg*conj(A(2))*A(4)*exp(1i*(kshg-ki-kpi)*x);

              B = [dp
          ds
          di
          dshg
          dps
          dpi]

              D = [-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x)+(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x)+(maxBeta/2)*kps*ks*A(5)*conj(A(2))*exp(1i*(kps-ks-kp)*x)+(maxBeta/2)*kpi*ki*A(6)*conj(A(3))*exp(1i*(kpi-ki-kp)*x);
                  (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kps*conj(A(1))*A(5)*exp(1i*(kps-kp-ks)*x)+(maxBeta/2)*kshg*kps*conj(A(5))*A(4)*exp(1i*(kshg-kps-ks)*x);
                  (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kpi*conj(A(1))*A(6)*exp(1i*(kpi-kp-ki)*x)+(maxBeta/2)*kshg*kpi*conj(A(6))*A(4)*exp(1i*(kshg-kpi-ki)*x);
                  -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)-(maxBeta/2)*ki*kps*A(3)*A(5)*exp(1i*(ki+kps-kshg)*x) -(maxBeta/2)*kpi*ks*A(6)*A(2)*exp(1i*(kpi+ks-kshg)*x);
                  -(maxBeta/2)*kp*ks*A(1)*A(2)*exp(1i*(kp+ks-kps)*x)+(maxBeta/2)*ki*kshg*conj(A(3))*A(4)*exp(1i*(kshg-ki-kps)*x);
                  -(maxBeta/2)*kp*ki*A(1)*A(3)*exp(1i*(kp+ki-kpi)*x)+(maxBeta/2)*ks*kshg*conj(A(2))*A(4)*exp(1i*(kshg-ki-kpi)*x)];

I don't understand why MATLAB can stack the variables but not the calculated values which are the same.

This is for use in a coupled differential equation solver whereby A(1:6) are unknown and thus defining variables initially is not an option.

Pre-thanks for any help

Tom

[jonas]

It looks like the variables are concatinated horizontally whereas the other one is vertical. When you copied the equations the ; sign went from being a 'do not display' sign to 'next row please' sign.

[Thomas Dixon]

Hi Jonas,

Thanks for your input. I believe I want a new row/column for example when I had 4 coupled equations I used the following code:

dA = @(x,A)[-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x) + (maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x);
        (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x);
         (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x);
         -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)];

However now when I add some furhter terms it says it can not concatenate them. I have then simplified this to show the problem but essentially I don't understand why matrix B can be made and matrix D cannot where:

   dp = -(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x)+(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x)+(maxBeta/2)*kps*ks*A(5)*conj(A(2))*exp(1i*(kps-ks-kp)*x)+(maxBeta/2)*kpi*ki*A(6)*conj(A(3))*exp(1i*(kpi-ki-kp)*x);
          ds = (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kps*conj(A(1))*A(5)*exp(1i*(kps-kp-ks)*x)+(maxBeta/2)*kshg*kps*conj(A(5))*A(4)*exp(1i*(kshg-kps-ks)*x);
          di = (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kpi*conj(A(1))*A(6)*exp(1i*(kpi-kp-ki)*x)+(maxBeta/2)*kshg*kpi*conj(A(6))*A(4)*exp(1i*(kshg-kpi-ki)*x);
          dshg = -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)-(maxBeta/2)*ki*kps*A(3)*A(5)*exp(1i*(ki+kps-kshg)*x) -(maxBeta/2)*kpi*ks*A(6)*A(2)*exp(1i*(kpi+ks-kshg)*x);
          dps = -(maxBeta/2)*kp*ks*A(1)*A(2)*exp(1i*(kp+ks-kps)*x)+(maxBeta/2)*ki*kshg*conj(A(3))*A(4)*exp(1i*(kshg-ki-kps)*x);
          dpi = -(maxBeta/2)*kp*ki*A(1)*A(3)*exp(1i*(kp+ki-kpi)*x)+(maxBeta/2)*ks*kshg*conj(A(2))*A(4)*exp(1i*(kshg-ki-kpi)*x);

          B = [dp;
      ds;
      di;
      dshg;
      dps;
      dpi]

          D = [-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x)+(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x)+(maxBeta/2)*kps*ks*A(5)*conj(A(2))*exp(1i*(kps-ks-kp)*x)+(maxBeta/2)*kpi*ki*A(6)*conj(A(3))*exp(1i*(kpi-ki-kp)*x);
              (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kps*conj(A(1))*A(5)*exp(1i*(kps-kp-ks)*x)+(maxBeta/2)*kshg*kps*conj(A(5))*A(4)*exp(1i*(kshg-kps-ks)*x);
              (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kpi*conj(A(1))*A(6)*exp(1i*(kpi-kp-ki)*x)+(maxBeta/2)*kshg*kpi*conj(A(6))*A(4)*exp(1i*(kshg-kpi-ki)*x);
              -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)-(maxBeta/2)*ki*kps*A(3)*A(5)*exp(1i*(ki+kps-kshg)*x) -(maxBeta/2)*kpi*ks*A(6)*A(2)*exp(1i*(kpi+ks-kshg)*x);
              -(maxBeta/2)*kp*ks*A(1)*A(2)*exp(1i*(kp+ks-kps)*x)+(maxBeta/2)*ki*kshg*conj(A(3))*A(4)*exp(1i*(kshg-ki-kps)*x);
              -(maxBeta/2)*kp*ki*A(1)*A(3)*exp(1i*(kp+ki-kpi)*x)+(maxBeta/2)*ks*kshg*conj(A(2))*A(4)*exp(1i*(kshg-ki-kpi)*x)];

Where the variables are defined as above. The problem I have is that I see each row as a simple number in the simplified version and in my workspace I can see the numbers corresponding to the variables in matrix B. But then for some reason when I put in the equations relating to the variables it stops working. In the full code i would not know the variables A(n) because it is being simultaneously solved in the ode45.

Answer 1

[Matt J]

You have a stray space in your expression for the 4th entry of D. This makes Matlab see two entries instead of one. Copy over it with the following,

              D = [-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x)+(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x)+(maxBeta/2)*kps*ks*A(5)*conj(A(2))*exp(1i*(kps-ks-kp)*x)+(maxBeta/2)*kpi*ki*A(6)*conj(A(3))*exp(1i*(kpi-ki-kp)*x);
                  (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kps*conj(A(1))*A(5)*exp(1i*(kps-kp-ks)*x)+(maxBeta/2)*kshg*kps*conj(A(5))*A(4)*exp(1i*(kshg-kps-ks)*x);
                  (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x)+(maxBeta/2)*kp*kpi*conj(A(1))*A(6)*exp(1i*(kpi-kp-ki)*x)+(maxBeta/2)*kshg*kpi*conj(A(6))*A(4)*exp(1i*(kshg-kpi-ki)*x);
                  -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)-(maxBeta/2)*ki*kps*A(3)*A(5)*exp(1i*(ki+kps-kshg)*x)-(maxBeta/2)*kpi*ks*A(6)*A(2)*exp(1i*(kpi+ks-kshg)*x);
                  -(maxBeta/2)*kp*ks*A(1)*A(2)*exp(1i*(kp+ks-kps)*x)+(maxBeta/2)*ki*kshg*conj(A(3))*A(4)*exp(1i*(kshg-ki-kps)*x);
                  -(maxBeta/2)*kp*ki*A(1)*A(3)*exp(1i*(kp+ki-kpi)*x)+(maxBeta/2)*ks*kshg*conj(A(2))*A(4)*exp(1i*(kshg-ki-kpi)*x)];

[Thomas Dixon]

Thanks for this. It is a complete oversight by myelf. I do wonder though in the previous one I had many spaces and MATLAB dealth with it differently is there a reason for this?

[Matt J]

What is "the previous one"?

[Thomas Dixon]

Apologies, in the 4 long vector/matrix I put:

dA = @(x,A)[-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x) + (maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x);
        (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x);
         (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x);
         -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)];

where there is a space between the plus sign in row 1. This doesn't seem to cause the same problem.

[Matt J]

The difference is that you had spaces on both sides of the '+' so Matlab knew you weren't trying to use it as a unary operator. This version won't work,

>> dA = @(x,A)[-(maxBeta/2)*ks*ki*A(2)*A(3)*exp(-1i*delk*x) +(maxBeta/2)*kshg*A(4)*kp*conj(A(1))*exp(1i*(kshg-2*kp)*x);
        (maxBeta/2)*ki*kp*conj(A(3))*A(1)*exp(1i*delk*x);
         (maxBeta/2)*ks*kp*conj(A(2))*A(1)*exp(1i*delk*x);
         -(maxBeta/4)*kp^2*A(1)^2*exp(1i*(2*kp-kshg)*x)];

[Thomas Dixon]

Not all heroes wear their pants on the outside.

This has been incredibly helpful, thanks a lot.

[Matt J]

Not all heroes wear their pants on the outside.

Neither do I.