How to use semiology using data given in .txt form

I put the command

HbData=dlmread('HbSpectra.txt');

into the script but I dont know how to proceed from there with the semilogy

Answer 1

[Walter Roberson]

Independent_Variable = HbData(:,1);
First_Dependent_Variable = HbData(:,2);
First_Marker = 'o';
semilogy(Independent_Variable, First_Dependent_Variable, First_Marker)

You should be able to proceed from there.