# [Calc] Combined charts with independent Y axis

Calc allows several data series to be displayed on a single chart. When series are loosely related, you can even combine two styles, such as bars and lines, to emphasize the difference between the series.

However, in order to be able to display the subtle variations in the series, they should have the same order of magnitude, otherwise the one with smaller variations will look like a “flat” line, no matter how the Y-axis range is tweaked. Think for example of a raw series and its variation (in %).

Artificially scaling the smaller series through a multiplicative factor is not acceptable since Y-axis labelling will no longer be significant.

I went through the Calc manual, notably chapter 3, but could not find how to combine two logically independent charts (sharing the same X axis but with huge Y discrepancies) on the same graph. One one the series could be labelled with the primary Y axis on the left and the second with the secondary Y axis on the right.

I remember this was possible in Excel (I have not used it for a very long time, so don’t know if this is still the case): many data series could be displayed in a single chart and you had a “threshold” parameter two split the series into two sets. Then each set could be customised independently (chart style as bar, lines, …, axis range and style, …).

I am looking for a Calc equivalent. My present concern is with a rapidly growing series (from 0 to 10k+) and its rate of variation (in the range 0-10% related to the base X-units - samples are spaced in time). The first series completely dwindles the second. I’d prefer two display both series in the same chart rather than two as it is easier to correlate “hiccups” on the variation with the raw series.

Note: trend lines do not answer my question.

Is there a simple way I do it?

Not entirely sure I understand, however the answer here offers an example of a chart with two Y axes, each scaled differently. Does that help?

Thanks, it solved my problem. The missing piece was how to associate a data series with an axis (step 3 in your procedure). The way to do it is even more friendly than the equivalent feature in Excel (from memory).

using 2 different Y axis sometimes helps ,

but the scientific way is to use “Half Log” or “Semi Log” chart .

The Logarithm scale allows you to put 10 and 1,000,000 together ,

and still be able to see changes in both numbers .

Not entirely sure I understand @oweng

What was there to not understand? And if you didn’t understand the simple question, how were you able to answer it?

the scientific way is @moshe11

no, that’s just another way.