Select
the red signal f(t) and the green weight function g(t) using the popdown
menus at right. The weight function is graphed at lower right in green.
The signal is graphed at bottom left in red. Accessing these menus causes
t to be reset to t = -2.
Grab
the [t] slider at the bottom to increase t . The function g(t-u) is
drawn in green in the lower left window. The time value is set using a slider under the window. The [>>] key starts an animation. The [<<] key resets t to
t = -2.
In
the window above it, the product f(u)g(t-u) is drawn in yellow, and
the area between it and the horizontal axis is shaded in blue.
In
the top left window, the signed area under f(u)g(t-u) is sketched; this
is the value of the convolution f*g at t.
The
convolution is graphed in light gray, which is overtraced in cyan as
t increases.
©
2001 H. Hohn