Dynamic Serial Chart

Question

I am having an issue in Dashboard.

I would like to create a Serial Chart (bar graph) for a stream (line vector) layer.

Each stream segment (record) has 8 different fields that I want included in this graph.

7 fields representing fish species and one representing stream miles. (See example).

Chinook

Chum

Coho

Steelhead

Cutthroat

Sculpin

Stream Miles

Documented

0.4

Documented

0.6

Documented

0.8

In this case I would like the first bar to represent the sum of stream miles for all records with documented Chinook. The second bar would represent the sum of stream miles for all records with documented Chum…. And so on.

This does not seem possible, I have been trying multiple ways and I am still failing.

Does anyone have a suggestion?

AaronThairJorgenson · Answer

Thank you! You are incredibly helpful!

It is working. When I run "test" the resulting table is populated with what appears to be the correct numbers!

Unfortunately when I build the table, adding in all the fields and changing the statistics to sum the graph is flat. (see image)

Any idea why this is happening?

I tried it with and without the

This is what my script looks like.

var fs = FeatureSetByPortalItem(
Portal('https://uwt-gis-geotech.maps.arcgis.com'),
'9b9856295f3943329bc225d0d7e8962f',
49,
['Chinook_Status', 'Chum_Status','Coho_Status', 'Mykiss_Status', 'Cutthroat_Status', 'Lamprey_Status', 'Sculpin_Status', 'Stream_Lenght_Miles'],
false
)

return Distinct(
fs,
[
{name: 'objectid', expression: 'objectid'},
{name: 'Chinook_Miles', expression: "CASE WHEN Chinook_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Chum_Miles', expression: "CASE WHEN Chum_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Coho_Miles', expression: "CASE WHEN Coho_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Mykiss_Miles', expression: "CASE WHEN Mykiss_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Cutthroat_Miles', expression: "CASE WHEN Cutthroat_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Lamprey_Miles', expression: "CASE WHEN Lamprey_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
{name: 'Sculpin_Miles', expression: "CASE WHEN Sculpin_Status = 'Documented' THEN Stream_Lenght_Miles ELSE 0 END"},
]
)

jcarlson · Answer

"//" denotes the following text to be a comment. The number is the only important part. If your service has a single layer, it will almost always be 0. If your service has more than one layer in it, the number will correspond to a specific layer. You can check the REST URL to see what the layer index actually is, or look at the end of the URL on the item's Overview page.

As for the fields, it's literally just an array of the fields you need. But try leaving it empty (that's "[]"), actually. I think the expression will still work.

In Data Expression fields need to be explicitly requested from the server to work with, so if you needed the stream miles and 7 fish species, you'd need to ask for those 8 fields. But the Distinct function sends a command to the Feature Service, so it doesn't necessarily need the fields in the FeatureSet when it makes the request, which is why maybe you can leave this part of the expression and an empty array.

AaronThairJorgenson · Answer

Thank you!

For

0, // or whatever layer index

I am a little confused, not sure what to do here. Any clarification would be much appreciated!

I am also a little confused with

['fields', 'you', 'need']

For this do I use

['Chinook', 'Chum', 'Stream_Miles']

Thank you so much for your help! This is all new to me (and kind of fun to learn)