Select a function f(u) of period 2π using the menu at lower right.

The main graphing window shows the graph of the function f(ωt), where ω = 2π, in cyan. This function has period T and circular frequency ω.

The periodic system response of the harmonic oscillator with natural circular frequency ω_n = 1 is displayed in yellow. It is a solution x of the equation x" + x = f(ωt).

Vary the period T of the input signal using the slider at right, or using the <,> keys.

Above the T slider the graph of the root mean square magnitude of the system response is plotted as a function of T. The currently chosen value of T is indicated by a yellow line segment.

Roll the cursor over the main graphing window to produce crosshairs and a readout of t and x.

Roll the cursor over the RMS window to produce a readout of the value of the root mean square magnitude of the system response. A mouse click over that window produces a line indicating the RMS height.

c 2001 H. Hohn