Apache OpenOffice (AOO) Bugzilla – Issue 74509

Chart2: Logarithmic Scale, various bases for LOG

Last modified: 2013-09-25 20:41:41 UTC

*Logarithmic Scale* - Different Bases TARGET ====== Chart2 Reimplementation This feature request should be integrated into the "Scales and Intervals Specification" (http://specs.openoffice.org/chart/Chart_Scales_and_Intervals.odt) When using a logarithmic scale, the logarithm base is usually 10. Most of the time this is indeed the way it should be, because at a log step of 1, the data changes by a factor of 10. (=> therefore easy visualisation) However, there are some situations where a different base for the logarithm is needed. EXAMPLE ======= When working with audio frequencies, the frequency often doubles. To accommodate this, the base of the logarithm must be 2. One common example is that of an audiogram. The frequencies recorded are usually: 125 Hz, 250 Hz, 500 Hz, 1000 Hz, 2000 Hz, 4000 Hz and 8000 Hz. For an example of an audiogram see http://www.sfu.ca/sonic-studio/handbook/Audiogram.html . Please note, that both the x-axis and the y-axis of the audiogram are logarithmic. Log2 is also often used in computer sciences, see e.g. http://logbase2.blogspot.com/2005/12/double-double-toil-and-trouble.html (the graphic on blogging) and in other branches, where doubling time is relevant (e.g. pharmacodynamics, epidemiology). Some other bases might also be useful, like e (=2.72...). REQUIREMENTS ============ 1. ability to choose the base of the logarithmic scale 2. DEFAULT: checkbox with base 10 (this is the most useful, therefore checked by default) 3. base 2 (checkbox unchecked) 4. natural logarithm (base e, checkbox unchecked) 5. custom value: field to type a number ( greater then 1; I believe numbers between (0,1) are very rarely used, IF at all)

yes, I think that would be a useful feature in future

accepted

reset to new

this is already mostly implemented - it's just not intuitive... you have to set the major interval to log10(x^2)-log10(x) where x is the base you'd like base 10 would have a major interval of 1.0 (duh) base 2 would have a major interval of 0.30102999566398 base e would have a major interval of 0.43429448190325 i think the ui changes requested here should just update the major interval because that would be very easy to implement and quite intuitive the only problem i can think of is somehow making the labels in terms of e when using that as the base since all the decimal stuff would be confusing