My quest for the best way to visualize figures on different scales

[datanibbler]

Hi,

I have two figures, both out of an Excel_list, that I want to display in a barchart. Sounds simple, no? Well, take this:

- The first figure is "lorries arriving on a given day" which usually numbers in the dozens or so.

- The second is "boxes arriving on a given day" which usually numbers in the hundreds (every lorry can contain any number of boxes)

I want to display the two as close as possible so that it is clear at first sight which two figures (a # of lorries and a # of boxes) are associated with a given day.

- I cannot use one chart with the Trellis_option (which would effectually give me two charts) as the two scales are so different - the axes
   automatically adapt to the largest figure (which would be a # of boxes), so the # of lorries would be hardly visible.

- Putting two separate charts side by side is quite ok, but it still requires "looking twice", so to speak, to notice the two different figures
   associated with one day.

One thing that would be a solution if I can do it which I don't know is creating a horizontal barchart with the 0_line in the middle and with the bars for the lorries going right and the bars for boxes going left - but I don't know if I could use two different scales with that - I rather doubt it.

Now I came up with the idea of using two separate charts below each other and turning the lower one around - with the columns going down, not up. Then I just have to deactivate the display of the dimension for one of them and move them close to each other and get rid of a part of the frames.

Maybe someone here has some idea that could help me to further improve this visualization? There are also some more figures to come, I don't know whether it will be possible/ sensible to display those in the same diagram(s).

Thanks a lot!

Best regards,

DataNibbler

[datanibbler]

Hi flipside,

I tried this.

As I said, I cannot display the values in or on the segments because when the lines for early and late shift are very close to each other (other than in your example) it becomes quite illegible.

I guess I cannot use the formula_property "offset" with lines, can I?

[flipside]

This was just to show the possibility of stacking line charts but it sounds like you would need to show the axes in your case if there are too many data points. You can specify on the Presentation tab the number of data values to display which means they won't show when nothing is selected (ie. all data showing) but will do when the chart is filtered enough to do so.

I never use the offset property so can't comment on that.

[datanibbler]

Okay.

I guess I cannot in any way colour the area between the "ground_line" and any one line, can I?

[flipside]

Don't think so. There's no option in Style and it doesn't work if everything is just a line chart either.

[quriouss]

I think you might be able to change the line chart to an area chart, and change the colouring to an expression, but I'm getting to the edge of my comfort zone already...

[datanibbler]

Hi,

there is no such thing as an "area chart" afaIk. Some other chart type like the mecco or block chart might be used to that end - but in this instance, the core idea is having just one chart for the two (# of lorries and # of boxes) so as to have only one x-axis (days)

Best regards,

DataNibbler

P.S.: But still, things might change as more figures come along to be included in the charts. I'll see about that tomorrow.

Now it's time to switch to my second job 😉

[datanibbler]

Hi,

I keep on having some trouble with this type of chart.

I decided to leave out the distinction into early and late shift with which our customer probably does not bother too much and have just one line in the upper half of my chart being the total # of boxes.

However, it seems that depending on how I set up the y-axis (I have to adapt it to accomodate the largest possible figures), that second ground_line separating the two halves does tend to get lost.

Do you know how to avoid that?

Best regards,

DataNibbler

[quriouss]

In the "Line Chart" scroll down the options to "Appearance" and then "Presentation".  In there is the option for an Area Chart.  All it does is shade the area under the chart.

However it seems, after a brief examination, that if you colour the lines by an expression you then lose the area-effect.  However, I think the area effect does help this to stand out.

[flipside]

Difficult to say without seeing how you've set it up. AFAIK you shouldn't need to set a scale maximum if that's what you mean.

[datanibbler]

Hi Quriouss,

I tried this out - but it seems I cannot even add a second measure to that? I selected a line_chart and used the second-to-last variant on the "design" tab of the dialog - that is like an area chart. With just one line, that worked fine.

<=> When I added a second line, it all got crammed together on one point of the dimension somehow.

Can you explain a bit more about how to do it?

Thanks a lot!

Best regards,

DataNibbler