The function plot.plsca displays four plots:
1) the circles of correlations of the X-scores (T-components) and the Y-scores (U-components)
2) the plot of T-components (t1,t2) and the plot of U-components (u1,u1)
3) barplots of the explained variances and communalities
4) the dot charts with (t1,u1) and (t2,u2)