clear % L4 p 17
A={'sin(x)','x.^2.*sin(x)','exp(sin(x))'}
x=0:0.01:2*pi;
mycolor={'blue','cyan','magenta'}
currentwidth=[1,2,5]

leg={}
 for f=A
    k=1
    while ~strcmp(A{k},f{:})
        k=k+1
    end
    r=plot(x,eval(f{:}))
    set(r,'color',mycolor{k},'linewidth',currentwidth(k))
    leg=union(leg,f{:})
    hold on
end       
grid on
l=legend(leg{:}), set(l,'fontsize',12)
set(l,'location','best')    % add comment