reverse order for y-axis

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Level 1

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reverse order for y-axis

I'm sorry if this has been asked already, but is there a way to reverse the order of the y-axis in a scatter graph? I wanted both the y and x-axis to cross at 0, but the y axis to go from zero down?

An example of what I'm after can be seen from the following link:

[http://www.up.ac.za/academic/civil/divisions/geotechnical/pgcourses/sgm781/them es/theme2/images/avgcons.jpg]

Posted on Jul 28, 2009 6:15 AM

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Answer 1

Jul 28, 2009 7:14 AM in response to forgotten025

f,

Select your Chart and then Arrange > Flip Vertically. Now you have what you want except that your axis labels are also inverted. You can make new labels on text boxes or tables and position them to cover the originals.

Jerry

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Answer 2

forgotten025 Author

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Jul 29, 2009 1:16 AM in response to Jerrold Green1

Jerry,

Thanks for your reply, but is that the only way to do it? Maybe there is another way around, without flipping everything? I need this for my thesis and I've got around 50+ graphs, so I don't really want to rename everything for all of them.

Thanks again.

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Answer 3

Jul 29, 2009 5:22 AM in response to forgotten025

f,

There are other ways to do it, but they are all tricks or overrides. Numbers simply doesn't have the capability of displaying positive Y values that increase downward. Plus is upward, minus is downward. I gave you what I consider the most convenient method in that it doesn't involve changing the underlying spreadsheet values.

By the way, the examples you linked to all look like continuous functions. Are you aware that OSX has a built-in application dedicated to graphing functions? You might want to check out Grapher.app.

Jerry

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Answer 4

Badunit

Level 7

31,172 points

Jul 29, 2009 5:23 AM in response to forgotten025

Another option for the Y axis is to plot the negative of your values then adjust the format of the Y axis numbers so they show as positive. Choose custom format (in the chart inspector, axis tab) then click on the "+". It will add a format for "if less than zero". Accept it as it is and it should be correct.

To put the X axis numbers on the top, you'll have to "not show" the X axis values and then put your own on the top. I suggest making a one-row table with no borders for that, some people use text boxes.

Not the most elegant solution but it works.

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Answer 5

forgotten025 Author

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Jul 29, 2009 7:01 AM in response to Badunit

Jerry,

I'm plotting data points, not a function so the Grapher.app isn't much help to me, but thanks for telling me about it (might be useful later). Having the y axis reversed isn't as important to me as having the x and y axis crossing at zero. I don't mind having the downward values as minus (as is normal), but now if I plot it the x and y axis don't cross at zero!! Surely this is a basic feature that should be available?

If possible maybe you could let me know of any other tricks or overrides that might be useful?

Badunit,

Thanks for your suggestion, I already tried that method, and as I said before my main problem is the x and y axis not crossing at zero (I'm studying engineering so they are very fussy about these details, and personally I'm a bit of a perfectionist), also manually putting in the x axis for 50+ graphs (all with varying scales) is something I'd rather avoid!

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Answer 6

Badunit

Level 7

31,172 points

Jul 29, 2009 7:26 AM in response to forgotten025

I'm not sure why you can't get X & Y to cross at zero, except on the logarithmic chart when X can't be zero. Did you specify the min and max for each axis?

I can see why you wouldn't want to manually put the X axis values on 50+ charts. I suppose they are fussy about the X axis values having to be on the top? I am an engineer but almost every graph that had only positive Y values had 0,0 at the bottom left, Y values increasing as you went up, and the X axis at the bottom (the typical construction). The charts you are required to make are interesting but strange to me.

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Answer 7

Jul 29, 2009 8:06 AM in response to forgotten025

f,

All the tricks involve adding text or graphics overlaying or in place of whatever the Chart would have created on its own, sometimes in combination with adding an offset or multiplication factor to change the data, and where it would fall on the chart.

It's a homework assignment, I assume. It's not supposed to be automatic. So changing 50 charts takes an hour or so. You'll survive. I had none of these tools when I studied engineering.

Jerry

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Answer 8

Badunit

Level 7

31,172 points

Jul 29, 2009 2:23 PM in response to Jerrold Green1

Jerrold Green1 wrote:
I had none of these tools when I studied engineering.

Now that you mention it, neither did I. Graphs were something you did by hand on graph paper and you fit the curve with drafting tools (usually with a French curve or a flexible curve).

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Answer 9

Badunit

Level 7

31,172 points

Jul 29, 2009 2:42 PM in response to forgotten025

It just dawned on me what the problem of "crossing at 0" is all about. You need the two zeros to be on the same corner of the chart which means you need the X axis values at the top. I get it now. The only solutions I know of have been presented already. If I think of something else, I'll let you know.

One problem to note with using negative Y's is that a few of the trendlines (such as the ones you might want to use) don't work with negative numbers.

Message was edited by: Badunit

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Answer 10

forgotten025 Author

Level 1

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Jul 29, 2009 6:24 PM in response to Badunit

Thanks for all the help guys, I guess this is something only Apple can fully resolve.

Badunit, I'm not sure why they prefer the graphs being upside down, perhaps its perception, seeing as its modelling the settlement of soils, therefore if the graphs go down you can "visualise" the situation better. That's my opinion, seeing as modelling it going up will give the same answer.

Jerry, compared to drawing them all by hand, I'm sure I will survive labelling them again. I know many people (my lecturers included) do say that the new generation of engineers are too computer dependant, we panic too easily when the computers don't do what we want!

Thanks again for all help.

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