Given two sets of data, ##x## and ##y##, let's assume that the variable ##y## has a range of values that is much larger (or much smaller) than the range of ##x##.

It becomes then preferable to convert the ##y## variable's values to its logarithmic value and obtain a semi-log graph by plotting ##log(y)## vs ##x##. But why don't we simply plot the actual values of the variable ##y## with the distance between the marks on the y-axis representing a large value? The mark distance on the y and x axes does not have to be the same since the ##x## and ##y## variables can indicate different physical quantities...

Also, there seems to be no problem graphing an exponential function ##y=e^{x}##.

And when would a log-log graph be useful?

Thanks!