This applet is Creating Moving wave with mouse movement, designed by prof Hwang, modified layout by Ahmed.
Original applet [url=http://www.phy.ntnu.edu.tw/ntnujava/index.php?topic=2285.msg8517#new]Creating Moving wave with mouse movement[/url]
The following let you drag mouse inside the simulation region, and a moving wave will be generated with pre-set period (you can change it with slider).
If you change it to click mode, the wave will be generated for each click (when mouse release), the period of the wave is also controlled by yourself. Enjoy it!