% Speedup: general examples

clc; clf; clear

%% Generate data
cpus     = [ 1 2 4 8 16 32 64];  % #processors
time_cpu = [ 508.74  257.83  132.20  110.17  55.93 28.20  14.11];  % seconds

gpus     = [2 4 8 16 32 ];       % #processors
time_gpu = [7.576 3.509  1.712  0.925   0.692 ];                   % seconds

%% Speedup on basis of 2 CPUs/GPUs

s_cpu = time_cpu(2)./time_cpu;
s_gpu = time_gpu(1)./time_gpu;

%% ideal speedup wrt. 2 procs
best = cpus/2;

%%  Graphics
%plot(cpus,s_cpu,'*-');
%  both graphs with special "linespecs" and thicker lines
%  both axis are logarithmically
loglog(cpus,s_cpu,'*-b',gpus,s_gpu,'s-r','LineWidth',2);


%  Titel and Labels of Axis
title('Speedup for GPU vs. CPU implementation')
xlabel('Processors');
ylabel('Speedup on basis of 2 procs');

%  Tick of axis 
% 'XTick',[1 2 4 8 16 32 64]
set(gca,'XTick',cpus)
set(gca,'YTick',cpus/2)

%%  One more graph
hold on                      % Allows to continue the drawing in the same figure
loglog(cpus,best,'-g');      % one more graph in figure

legend('CPU','GPU','ideal'); % Legend of graphs

%% save graphics
saveas(gcf,'speedup_munich.jpg')