Matlab数据提取及画图修饰_坐标轴范围及刻度值

clc;clear;
close all
filename='J:\20160819-Multi_BOTDA\20160920-keyong2\static-flat\1\';
Tchirp='40ns';
BS50ns=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse50ns20GSBS.txt']);
BS30ns=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse30ns20GSBS.txt']);
BS20ns=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse20ns20GSBS.txt']);
BS10ns=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse10ns20GSBS.txt']);
BS5ns=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse5ns20GSBS.txt']);
BS0nsbase=load([filename,'Chirp',Tchirp,'\0ave100Chirp',Tchirp,'pulse0ns20GSBSbase.txt']);

Sa=20;%GSs
LBS=length(BS0nsbase);  
figure_FontSize=22;
figure_FontSize2=18;

figure(1);plot(BS50ns)
hold on;plot(BS30ns,'g')
hold on;plot(BS20ns,'m')
hold on;plot(BS10ns,'k')
hold on;plot(BS5ns,'r')
hold on;plot(BS0nsbase,'b-.')
legend('50ns','30ns','20ns','10ns','5ns','base')
xaxis=0:10000:LBS;
set(gca,'xtick',xaxis);
xaxisstr=num2cell(xaxis/Sa);
set(gca,'xticklabel',xaxisstr);
xlabel('Time (ns)')
ylabel('U (V)')