hold on option is not working in the present code

M = 0.2; L = 0.01; K = 0.1; G = 2; Pr = 2; s = 0.1; Ec = 0.01; m = 0.5; R = 0.5; fw = 0.5; a = 1; n = 0.5;
for M = [0 .1 .2]
    for fw = [-1 0 1]/2
ODE = @(x,y)[  y(2);  y(3);  (y(2)^2 - y(1)*y(3) + M*y(2) - K*y(5) - L*y(6))/(1+K);   y(5);  (y(2)*y(4) - y(1)*y(5) + K*(2*y(4) + y(3)))/G;
               y(7);  Pr*( m*y(2)*y(6) - s*y(6) - Ec*y(3)^2 - y(1)*y(7) )/(1+(4/3)*R) ];
BC = @(ya,yb)[ya(1)-fw; ya(2)-1-a*(1+K)*ya(3); ya(4)+n*ya(3); ya(7)-1; yb([2;4;6])];  xa = 0; xb = 6; x = linspace(xa,xb,101);
solinit = bvpinit(x,[0 1 0 1 0 1 0]); sol = bvp5c(ODE,BC,solinit);  S = deval(sol,x); f0 = deval(sol,0); 
set( 0,'DefaultAxesColorOrder',[1 0 0; 0 1 0; 0 0 0] )  
figure(11),plot(x,S(2,:),'LineWidth',2); hold on, 
ax = gca; ax.XColor = 'black';  ax.YColor = 'black'; ax.XAxis.FontSize = 10; ax.YAxis.FontSize = 10; ax.FontWeight = 'bold';   
xlabel('\bf\eta','Color','blue'); ylabel('\bff^{\prime}(\eta)','Color','blue'); 
L(1) = plot(nan,nan,'r-','Linewidth',2); L(2) = plot(nan,nan,'g-','Linewidth',2); L(3) = plot(nan,nan,'k-','Linewidth',2); 
legend(L,{'\color{red}\bffw = - 0.5','\color{green}\bffw = 0','\color{black}\bffw = 0.5'},'Box','off'); 
    end
end

Error using vertcat
Dimensions of arrays being concatenated are not consistent.

Error in solution (line 4)
ODE = @(x,y)[ y(2); y(3); (y(2)^2 - y(1)*y(3) + M*y(2) - K*y(5) - L*y(6))/(1+K); y(5); (y(2)*y(4) - y(1)*y(5) + K*(2*y(4) + y(3)))/G;

Error in bvparguments (line 105)
testODE = ode(x1,y1,odeExtras{:});

Error in bvp5c (line 135)
bvparguments(solver_name,ode,bc,solinit,options);

[Adam Danz]

I formatted your code (in the future, please use code formatting (see instructions).

But still, the code is presented very poorly and many people would avoid digging in simply because of it's organization. To make the code as easy to read as possible, start off by using new lines for each statement.

[Cris LaPierre]

And I ran your code so that the error messages are displayed.

[MINATI PATRA]

@Adam Thanks for your suggestion, I will work on it.

@Cris What next Dear?

[MINATI PATRA]

Due to legend style, the code stops. I think we should modify that. Please help.

Answer 1

[the cyclist]

The problem doesn't really have anything to do with the legend. The fundamental problem is that you first define L as a parameter, but inside the for loop, you then use L as a 1x3 vector of graphics handles from the plots.

Therefore, when you get to the second iteration of the for loop, this expression

% I commented this so that it does not run
% y(2)^2 - y(1)*y(3) + M*y(2) - K*y(5) - L*y(6)

is a spurious 1x3 vector. That's why you get a concatenation error.

Change one of those variable names to something else.

L = 0.01;
K = 0.1;
G = 2;
Pr = 2;
s = 0.1;
Ec = 0.01;
m = 0.5;
R = 0.5;
a = 1;
n = 0.5;

xa = 0;
xb = 6;
x = linspace(xa,xb,101);

for M = [0 .1 .2]
    for fw = [-1 0 1]/2
        ODE = @(x,y)[  y(2);  y(3);  (y(2)^2 - y(1)*y(3) + M*y(2) - K*y(5) - L*y(6))/(1+K);   y(5);  (y(2)*y(4) - y(1)*y(5) + K*(2*y(4) + y(3)))/G;
                       y(7);  Pr*( m*y(2)*y(6) - s*y(6) - Ec*y(3)^2 - y(1)*y(7) )/(1+(4/3)*R) ];
        BC = @(ya,yb)[ya(1)-fw; ya(2)-1-a*(1+K)*ya(3); ya(4)+n*ya(3); ya(7)-1; yb([2;4;6])];
        solinit = bvpinit(x,[0 1 0 1 0 1 0]);
        sol = bvp5c(ODE,BC,solinit);
        S = deval(sol,x); 
        set( 0,'DefaultAxesColorOrder',[1 0 0; 0 1 0; 0 0 0] )  
        figure(11),plot(x,S(2,:),'LineWidth',2);
        hold on, 
        ax = gca;
        ax.XColor = 'black';
        ax.YColor = 'black';
        ax.XAxis.FontSize = 10;
        ax.YAxis.FontSize = 10;
        ax.FontWeight = 'bold';   
        xlabel('\bf\eta','Color','blue');
        ylabel('\bff^{\prime}(\eta)','Color','blue'); 
        LL(1) = plot(nan,nan,'r-','Linewidth',2);
        LL(2) = plot(nan,nan,'g-','Linewidth',2);
        LL(3) = plot(nan,nan,'k-','Linewidth',2); 
        legend(LL,{'\color{red}\bffw = - 0.5','\color{green}\bffw = 0','\color{black}\bffw = 0.5'},'Box','off'); 
    end
end

[Adam Danz]

I've moved by duplilcate answer here since the cyclist and I answered nearly at the same time and we both came to the same conclusion.

The error occurs because you are overwriting the variable L defined in the first line of your code. Your 3 plot() commands are storing the output handles in a variable named L which overwrites L with a 1x3 vector. Then in the ODE() function, the vertical concatenation throws an error because it expects L to be a scalar value.

Solution:

Rename the 3 plot() outputs and rename the first input to your legend() funciton.

This problem may have been avoided by writing cleaner code where each statement gets its own line.

[MINATI PATRA]

@

the cyclist

It was a huge mistake (how can I do that), Thanks for correcting.