MATLAB: I an not getting multiple graphs after running two ‘for’ loops for different parameters solving ode using ‘bvp4c’

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The equations that I have to solve are :
f"=g(g^2+gamma^2)/(g^2+lambda*gamma^2) ------ (1)
g'= 1/3f'^2-2/3(f*f") ------------------------(2)
t"+4*Rd*t"/3+ 2*Pr*f*t'/3+ Nb*t'*p'+Nt*(t')^2= 0------(3)
p"+(2*Lew*f*p')/3+ Nt*t"/Nb= 0 ------------------------(4)
Where 'lambda', 'gamma', 'Rd', 'Pr', 'Lew', 'Nb', 'Nt' are some parameters
where the boundary conditions are : f=0, f'= delta, t=1, p=1 at y=0 f'–>0, t–>0, p–>0 as y—-> infinity
I tried to solve these equations using 'bvp4c'
I am not getting multiple graphs even after running two 'for' loops for different values of parameters 'lambda', 'Rd'
Please help.
function sol= proj
clc;clf;clear;
global lambda gama Pr Rd Lew Nb Nt delta
delta=1;
gama=1;
Pr=2;
Lew=2; 
Nb=1;
Nt=2;
pp=[0.5:0.5:1.5];
qq=[0 1 2];
figure(1)
plot(2,1);hold on
solinit= bvpinit([0:0.01:10],[1,0,0,0,0,0,0]);
for i= 1:numel(pp)
    k=1;
    for lambda=pp(i)
    Rd=qq(k);
sol= bvp4c(@projfun,@projbc,solinit);
k=k+1;
solinit= sol;
    end  
end
plot(2,1);plot(sol.x,sol.y(4,:));hold on 
end
function f= projfun(x,y)
global lambda gama Pr Rd Lew Nb Nt
f= [y(2)
    y(3)*(y(3)^2+gama^2)/(y(3)^2+lambda*gama^2)
    y(2)^2/3-(2*y(1)*y(3)*(y(3)^2+gama^2))/(3*(y(3)^2+lambda*gama^2))
    y(5)
    -((2*Pr*y(1)*y(5))/3 + Nb*y(5)*y(7) + Nt*y(5)^2)/(1+4*Rd/3)
    y(7)
    -(2*Lew*y(1)*y(7))+ Nt*((2*Pr*y(1)*y(5))/3 + Nb*y(5)*y(7) + Nt*y(5)^2)/Nb*(1+4*Rd/3)];
end
function res= projbc(ya,yb)
global delta
res= [ya(1); ya(2)-delta; ya(4)-1.0; ya(6)-1.0; yb(2); yb(4); yb(6)];
end

Best Answer

Your code does not ask for multiple graphs.
You start with
    plot(2,1);hold on
which designates a single point. You do not specify at least two points and you do not specify a marker, so nothing shows up on the display when you do this. Mostly it has an effect on the automatic axes boundary selection, otherwise no effect on the display.
You then have
    for i= 1:numel(pp)
        k=1;
        for lambda=pp(i)
            Rd=qq(k);
            sol= bvp4c(@projfun,@projbc,solinit);
            k=k+1;
            solinit= sol;
        end
    end
which kind of looks like a double nested for loop, but the "for lambda=pp(i)" is just a fancy way of saying "lambda=pp(i)" there since i is not a vector. So anyhow, you have a for i loop there, and there are no graphics within the loop. I am not clear as to why you are feeding solinit back through several rounds, but I guess there might be a reason for that.
After the loop you have
    plot(2,1);plot(sol.x,sol.y(4,:));hold on
the plot(2,1) plots on top of the previous plot(2,1) -- except, as noted before, since that is only a single point and you did not specify a marker, that doesn't change the display (except perhaps the xlim and ylim chosen.)
The plot(sol.x,sol.y(4,:)) part selects the 4th output variable out of the 7 output variables and plots a line with just that one variable. So you get one line out of that.
... and that's the end of your program. You plotted the same invisible point twice, and you plot one line. The best you could hope for with that is the line together with a marker at (2,1) -- at most 2 outputs, not 9.
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