Warning! Graphs and del.icio.us references ahead! Non-del.icio.us nerds beware! Webmaster tool Grafolicious makes a neat-o line graph of del.icio.us user bookmark frequency of a web site over time ...

The frequency distribution is shown in a column chart. Note, you can choose a line chart, bar graph or XY Scatter chart, if those suit your data presentation better.

You should be able to work out the frequency of a wave from a displacement-time graph – remember the frequency is the number of waves per second.

f = frequency = number of waves produced by a source per second, in hertz Hz. T = period = time it takes for one complete vibration or oscillation, in seconds s. A boat at sea bobs up and down as ...