BeIzebu69 -

You could use a Line chart type or an XY (Scatter) chart type.

The XY (Scatter) chart gives you more control over some formatting. To use
it, arrange data in worksheet cells with X values in a column on the left,
e.g., 1,2,3,4,... and Y values in an adjacent column on the right, e.g.,
100,100,100,100,300,300,200,... Select all data, e.g., 2 columns by 15 rows,
click the Chart Wizard button, choose XY (Scatter), etc. Format the data
series to show markers and lines.

- Mike
http://www.mikemiddleton.com

"BeIzebu69" wrote in message
ps.com...
hi all,
I need to graph multiple constant functions, each graph has a range of
duration in x,each range is noncoincident between functions, the idea
is that they are graph of superposed form. Some idea. An example in the
image.
sorry my english ;)
best regards