% Compute the Sound Absorption Average (SAA) % from absorption measurements in diffuse field. % % Measurements performed on a 40 mm-thick rock wool % by Mickael Duranteau during his 'DEUST VAS 2' % internship at ENTPE in 2006. % % Commands for the rotation of tick labels are % borrowed from rotateticklabel.m % Written Oct 14, 2005 by Andy Bliss % Copyleft 2005 by Andy Bliss % % Everything else is copyleft 2006 luc.jaouen@matelys.com % cf. APMR on the web, % Standards/SAA % for more information clear all close all %%%%% %%%%% Load measurements in 1/3 octave bands %%%%% ranging from 100 to 8000 Hz %%%%% and compute the SAA %%%%% measurements = [0.19 0.15 0.50 0.67 0.89 0.86 1.04 1.05 1.01 1.07 0.67 0.80 0.76 0.82 0.71 0.74 0.71 0.74 0.78 0.99]; SAA = sum( measurements(4:15) ) / 12; string = sprintf('SAA: %.2f', SAA); disp(string); %%%%% %%%%% Show results %%%%% figure(1) set(gca,'FontSize',16) plot(measurements,'ko-','LineWidth',2) % Add two vertical red lines at 200 and 2500 Hz line([4 4],[0 1],'Color','red','Linewidth',2); line([15 15],[0 1],'Color','red','Linewidth',2); % Axis and their labels ylabel('Sound absorption coefficient') hh = xlabel('Frequency band (Hz)'); pos = get(hh,'pos'); set(hh,'pos',pos+[-0.5 0.2 0]) xt = [1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20]; xtlab = {'100';'125';'160';'200';'250';'315';'400';'500';'630';'800';'1000';'1250';'1600';'2000';'2500';'3150';'4000';'5000';'6300';'8000'}; set(gca,'Xtick',xt,'XTickLabel',xtlab,'xminortick','off') set(gca,'Ylim',[0 1.2]) set(gca,'Xlim',[0 21]) h = gca; rot = 45; a = get(h,'XTickLabel'); set(h,'XTickLabel',[]); b = get(h,'XTick'); c = get(h,'YTick'); if rot < 180 th = text(b,repmat(c(1)-.1*(c(2)-c(1)),length(b),1),a,'HorizontalAlignment','right','rotation',rot,'FontSize',16); else th = text(b,repmat(c(1)-.1*(c(2)-c(1)),length(b),1),a,'HorizontalAlignment','left','rotation',rot,'FontSize',16); end