I would like to only show these x-values
on the x-axes
xx=[0.0005 0.005 0.05 0.1 0.25 0.5 0.75 1 1.25 1.5];
Is it possible?
You can modify axis labels using XtTickLabel property. For example:
set(gca,'XTickLabel',[0.0005 0.005 0.05 0.1 0.25 0.5 0.75 1 1.25 1.5])
This will change only labels, not actual values on the plot. To check values as well you can use:
set(gca,'XTick',[0.0005 0.005 0.05 0.1 0.25 0.5 0.75 1 1.25 1.5]);
set(gca,'XScale','log'); % Your xx values seem to be logarithmic, so this can help.