Problem Plotting with Semilogy function

I am trying to plot using semilog and want to plot BER in log scale but its not working.

I tired different method to have y-axis in log scale but all of them are having linear results. Cooperation will be appreciated if someone can help me related with this.

blk =[100,150,200,250,300,350,400,450];
ber= [0.274726562500000,0.275013020833333,0.263476562500000,0.278125000000000,0.278619791666667,0.271618303571429,0.276972656250000,0.276549479166667];
%hold on

pplot1= semilogy(blk, ber, '-o','LineWidth',1,'MarkerSize',5) %----- important
%hold on

%set (gca, 'yscale' , 'log' );

xlabel('Block Lenths')
ylabel('BER')

Answer 1

[David Hill]

The semilogy function is plotting the y-axis on a logarithmic scale, but I think you can't tell because the data points are not separated by any significant amount.

[Muhammad Malik]

I tried to change the values which are significantly higher still it is not lograthmic scale.

[David Hill]

It sure looks lograthmic to me (the distance between each additional .1 gets smaller)!