Use this field to specify the variable indicating subgroups within arrays. Subsequent images are drawn by the Block Variable.Leave this empty if there is only one block in an array or no blocking variable is desired. Without a Block Variable, only one image per array is drawn.Note: When specifying a Block Variable, the x-Coordinate Variable and y-Coordinate Variable must be within-block coordinates.All of the variables in the specified data set are displayed in the Available Variables field.
Click to add the highlighted variable to the Block Variable field.