SPIKE Subcommand (IGRAPH command)

The SPIKE subcommand inserts spikes from individual data points to the specified location. Keywords for location include:

X1. Display spikes to the X1 axis.

X2. Display spikes to the X2 axis.

Y. Display spikes to the Y axis.

CORNER. Display spikes to the corner defined by the lowest displayed values of the X1, X2, and Y axes.

ORIGIN. Display spikes to the origin. The origin is the point defined by the 0 values for the X1, X2, and Y axes.

FLOOR. Display spikes to the “floor” defined by the X1 and X2 axes.

CENTROID. Display spikes to the point defined by the subgroup mean values of the X1, X2, and Y variables. CENTROID=TOTAL is no longer supported. Spikes are always drawn to subgroup means defined by color and/or style variables.

Example:

IGRAPH 
  /X1 = VAR(salbegin) TYPE = SCALE 
  /Y = VAR(salary) TYPE = SCALE 
  /COLOR = VAR(gender) TYPE = CATEGORICAL   
  /SPIKE CENTROID.