e423.m

学习Matlab循环语句的好例子

% Script file: E423.m
% Purpose:
% Calculate the Decibels

% Record of Revision
%   Date      Programmer         Description of change 
% =========  ============       =======================
%  13/06/08   ZMW                Original Code

% Define variables
% P2   ----the power level being measured
% P1      ----the reference power
% dB    -----the decibels

dB=zeros(1,39);
ii=1;
for P2=1:0.5:20
    dB(ii)=10*log(P2)/log(10);
    ii=ii+1;
end

P2=1:0.5:20;
plot(P2,dB,'r-');
%semilogx(P2,dB,'r-');
title('\bf P2 VS dB');
xlabel('\bf\itlog(P2)');
ylabel('\bf\itdB');