冲击响应谱计算的matlab程序(2)

disp(' Plot pseudo velocity? '); vchoice=input(' 1=yes 2=no ' ); if(vchoice==1) figure(2); %

% Convert to pseudo velocity %

for j=1:jnum

if iunit==1

x_pos(j)=386.*x_pos(j)/(2.*pi*fn(j)); x_neg(j)=386.*x_neg(j)/(2.*pi*fn(j)); else

x_pos(j)=x_pos(j)/(2.*pi*fn(j)); x_neg(j)=x_neg(j)/(2.*pi*fn(j)); end end %

srs_max = max(x_pos);

if max( abs(x_neg) ) > srs_max srs_max = max( abs(x_neg )); end

srs_min = min(x_pos);

if min( abs(x_neg) ) < srs_min srs_min = min( abs(x_neg )); end %

plot(fn,x_pos,fn,abs(x_neg),'-.'); %

if iunit==1

ylabel('Velocity (in/sec)'); else

ylabel('Velocity (m/sec)'); end

xlabel('Natural Frequency (Hz)'); Q=1./(2.*damp);

out5 = sprintf(' Pseudo Velocity Shock Response Spectrum Q=%g ',Q); title(out5); grid;

set(gca,'MinorGridLineStyle','none','GridLineStyle',':','XScale','log','YScale','log');

legend ('positive','negative',2); %

ymax= 10^(round(log10(srs_max)+0.8)); ymin= 10^(round(log10(srs_min)-0.6));

%

axis([fmin,fmax,ymin,ymax]); end