By default, the GBARLINE procedure ignores missing midpoint values for the chart variable. If you specify the MISSING option, then missing values are treated as a valid midpoint and are included on the axis. Missing values for the subgroup variables are always treated as valid subgroups.

When the value of the variable that is specified in the FREQ= option is missing, zero, or negative, the observation is excluded from the calculation of the chart statistic.

When the value of the variable specified in the SUMVAR= option is missing, the observation is excluded from the calculation of the chart statistic.

If all of the values for a response variable are missing for the bar chart, a midpoint is drawn, but no bar appears above it. For a line plot, no marker is drawn and the line connects the adjacent markers.