Add reference line and notes to chart

[akelic]

hi there

how can you add

1.a reference line to a chart which adapts to the scale when additional values are added (ie add a line which is say a numerical value of 20, and keep it at 20 despite the hieght of chart changing when more values are added

2. add a note to the time scale on x axis which again adapts to the charts but sticks the date you have added the note to (at the moment i draw an arrow and text box and add the note however when i add additional data the axis gets compressed and the arrow no longer represents the same time line)

[Andy Pope]

Various ways of adding datum lines to charts
http://www.andypope.info/charts/averageline.htm

Notes for specific data points
http://www.andypope.info/ngs/ng47.htm