topic Re: Sankey Diagram - weight in SAS Visual Analytics

Sankey Diagram - weight

gabras — Thu, 24 Jan 2019 21:01:00 GMT

Hi everybody,

i'm facing some problem understanding the usage of the weigth in sankey diagram on VA.

I have this kind of data

Trans_ID	Item	Order	Elapsed
1	A	1	120
1	B	2	120
1	C	3	180
1	D	4	30
2	A	1	120
2	B	2	30
3	A	1	60
3	A	2	60
4	B	1	120
4	A	2	60
4	C	3	30

I would like that the width of the path would represent the average of elapsed (used as weigth).

Is it possible? if yes, where i can change the aggregation measure for the weight.

Thank you

@FalkoSchulz can you help me?

Re: Sankey Diagram - weight

FalkoSchulz — Thu, 24 Jan 2019 22:50:16 GMT

Hi!

Note, that aggregation is done on path level and not on segment (or event) level. Taking your example - it renders as follow in VA 8.x:

Let's just look at one path for illustration purposes (A->B) as marked in above screenshot. Taking all events for this path the aggregated path weight is 150.

Let's add another transaction (#5) for the same path and it renders as:

The total weight of the same path is now 300 given the two contributing transactions (#2 and #5). If you want to see the average across all paths instead (so 150 in the example above) - you would change the aggregation of the weight variable in the data panel:

Hope this helps. Regards, Falko

Re: Sankey Diagram - weight

gabras — Fri, 25 Jan 2019 11:44:53 GMT

Hi @FalkoSchulz

if i understand correctly i have to change the aggregation method in the data properties in the lower left of the screen.

So it is not referring to diagram properties.

If it is, i can also set Median for the aggregation methods.

Is it correct?

Thank you

Re: Sankey Diagram - weight

FalkoSchulz — Sun, 27 Jan 2019 21:44:14 GMT

Hi,

Yes, that is correct - the applied aggregation is on data item level so something you adjust in the data panel. As per documentation - supported aggregations for the weight role include sum, average, minimum, or maximum.

Hope this helps. Regards, Falko

Re: Sankey Diagram - weight

gabras — Tue, 11 Jun 2019 16:33:29 GMT

Hi @FalkoSchulz ,

thank you for you answer.

I would ask you something about the diagram representation differences based on the weight aggregation you use.

the data are the same as i reported above.

If i use frequency as measure to determine the width of the path i have several path above 2 event (since i specified minimum path length = 2).

let's say i choose SUM as weight aggregation and i still have several path with more than 2 events.

If i choose AVARAGE the diagram shows me only paths with just 2 events.

I'm wondering why it could happen.

Thank you

Re: Sankey Diagram - weight

FalkoSchulz — Mon, 17 Jun 2019 11:05:54 GMT

Sorry for the delay in responding. As far as I remember the graph shouldn't change (in terms of number of paths displayed) if you change the aggregation. Are you able to share your data so I can see more details (the screens you shared indicate you have used a different data set than the one used in the first example). Or alternatively - can you try using the original data and see whether you see similar results?

Thanks, Falko