hold is on.
k = ishold
ishold returns 1 if hold is on, and 0 if it is not.
If hold is on, MATLAB preserves the current plot and all axes properties so that subsequent graphing commands add to the existing graph. In this case, the NextPlot property of both the current figure and axes is set to 'add'. If hold is 'off', NextPlot is set to 'replace'.
axes,figure,hold,newplot
(c) Copyright 1994 by The MathWorks, Inc.