xmin=0, xmax=5,
xtick={1,2,3,4},
xlabel={$\alpha$},
-xmajorgrids,
+%xmajorgrids,
ymin=0, ymax=60,
ylabel={GFlops},
ymajorgrids,
+ytick={10,20,30,40,50,60},
legend style={at={(0.03,0.97)},anchor=north west,nodes=right},
area legend]
\addplot[ybar,bar width=0.0457142857142857\figurewidth,bar shift=-0.0285714285714286\figurewidth,fill=black,draw=black] plot coordinates{ (1,28.1201594459724) (2,39.4770078207878) (3,46.729267222466) (4,51.1805955922042) };