How to reduce the data point density on graph?

Hello friends,

Below is my plotmatrix coding to compare three models with observed data. I would like to reduce the number of marks on the plot (see attached). Right now each plot has 365 points, i want to go with a step i.e. 1:10:end etc. Any help would be appreciated

[S,AX,BigAx,H,HAx]=plotmatrix(Average_modeling,'*r');

set(S,'MarkerSize',5);
set(H, 'FaceColor','b');

AX(1,1).YLabel.String='Obs';
AX(2,1).YLabel.String='M-1'; 
AX(3,1).YLabel.String='M-2';
AX(4,1).YLabel.String='M-3';

AX(4,1).XLabel.String='Obs';
AX(4,2).XLabel.String='M-1';
AX(4,3).XLabel.String='M-2';
AX(4,4).XLabel.String='M-3';
set(AX,'FontSize',14);