求助，matlab编程问题，我自己编了个小程序，不能达到预期结果，请教高手

程序：
function rk(A,x,h,y0)
i=1;
y(i,:)=y0;
m=length(A);
b=x(length(x));
while x(i)<b
     a=[x(i),y(i,:)];
    for l=1:m
         k1(l)=eval(A{l},a);
    end
     a=[x(i)+h/2,y(i,:)+h/2*k1];
    for l=1:l
         k2(l)=eval(A{l},a);
    end
     a=[x(i)+h/2,y(i,:)+h/2*k2];
    for l=1:m
         k3(l)=eval(A{l},a);
    end
     a=[x(i)+h,y(i,:)+h*k3];
    for l=1:m
         k4(l)=eval(A{l},a);
    end
     y(i+1,:)=y(i,:)+h/6*(k1+2*k2+2*k3+k4);
     i=i+1;
end
y,k1,k2,k3,k4
运行结果：
y1='-10*a(2)-9*a(3)+8';
y2='-9*a(2)-8*a(3)+7';
A=[{y1},{y2}];
rk(A,0:0.05:1,0.05,ones(1,2))

y =

    1.0000    1.0000
    0.6417    0.6716
    0.4972    0.5345
    0.4403    0.4758
    0.4193    0.4491
    0.4129    0.4356
    0.4126    0.4275
    0.4148    0.4216
    0.4181    0.4166
    0.4217    0.4120
    0.4255    0.4075
    0.4294    0.4030
    0.4334    0.3986
    0.4373    0.3941
    0.4413    0.3897
    0.4453    0.3852
    0.4493    0.3807
    0.4533    0.3762
    0.4574    0.3717
    0.4614    0.3672
    0.4655    0.3627


k1 =

    0.0809   -0.0904


k2 =

    0.0811   -0.0906


k3 =

    0.0811   -0.0906


k4 =

    0.0812   -0.0907
我想把中间的K1,k2,k3,k4都显示出来，该怎么做啊，请教赐教