If you have created a grid of plots using either strip_chart or split then you can use the relsize-family of commands to change the size of the columns or rows: adjust_grid_xrelsize, adjust_grid_yrelsize, adjust_grid_xrelsizes, and adjust_grid_yrelsizes. The singular forms are for when you want to adjust a single column (x) or row (y) size relative to the others, whereas the plural form let you give the relative sizes of the individual columns or rows; so

chips> adjust_grid_xrelsize(2, 2)
chips> adjust_grid_yrelsizes([1,2,3])

will set the width of the second column to be twice as large as the other columns whilst the rows are set so that the ratio of heights of the three columns are 1 to 2 to 3.

The following visualization shows the effect of these commands commands on the grid of plots created by a split(3,3,0.05,0.05) call.