How to show a range in a serial chart

[RachelS]

Hi,

Is it possible to show how many records fall within each range on a serial chart?

I've attached a spreadsheet to show what I mean.

Any help much appreciated.

Rachel

[jcarlson · Accepted solution]

What you're describing is a histogram, which is sort of a different animal from the serial chart. It's something others have expressed an interest in as well.

Fortunately, with the latest updates to Dashboards, you can use a Data Expression to create what you need. Try something like this:

var fs = [2,12,24,36,48,55,6,16,26,36,46,12,7,18,12,41]

// static list is for testing; use FeatureSetByPortalItem to get the actual values

var bins = {
    '0 to 10': {'attributes': {'bin':'0 to 10', 'count': 0}},
    '11 to 20': {'attributes': {'bin':'11 to 20', 'count': 0}},
    '21 to 30': {'attributes': {'bin':'21 to 30', 'count': 0}},
    '31 to 40': {'attributes': {'bin':'31 to 40', 'count': 0}},
    '41 to 50': {'attributes': {'bin':'41 to 50', 'count': 0}},
    '51 to 60': {'attributes': {'bin':'51 to 60', 'count': 0}}
}

for(var f in fs){
    if(fs[f] < 11){
        bins['0 to 10']['attributes']['count'] ++
    } else if(fs[f] < 21){
        bins['11 to 20']['attributes']['count'] ++
    } else if(fs[f] < 31){
        bins['21 to 30']['attributes']['count'] ++
    } else if(fs[f] < 41){
        bins['31 to 40']['attributes']['count'] ++
    } else if(fs[f] < 51){
        bins['41 to 50']['attributes']['count'] ++
    } else{
        bins['51 to 60']['attributes']['count'] ++
    }
}

var feat_arr = []

for(var b in bins){
    Push(feat_arr, bins[b])
}

var out_fs = {
    'fields': [{'name':'bin', 'type':'esriFieldTypeString'},
               {'name':'count', 'type':'esriFieldTypeInteger'}],
    'geometryType': '',
    'features': feat_arr
}

return FeatureSet(Text(out_fs))

This results in the following:

As you can see, Data Expressions can be very handy, if built properly. Best of luck!

[AliciaAdiwidjaja]

Hello!

Thank you so much for providing this detailed solution but I am having a bit of trouble using the FeatureSetByPortalItem function to get the actual values from my data layer to work. If it's alright, could you perhaps provide a few lines of code that demonstrate how to use the FeatureSetByPortalItem to retrieve field values from an existing feature layer to use in this histogram workflow? 

You see, while I know how to properly define the FeatureSetByPortalItem function with the specifics of my data layer's portal, item id, layer id, and field I want to pull from, I just don't understand how I am supposed to implement it into the histogram code. My apologies if this seems like a silly question but as someone who is just barely starting to learn Arcade, anything helps!

[jcarlson]

I forgot, using a for loop with a FeatureSet is a little different from an array. Let's assume that fs in your case is a FeatureSet.. In that case, use the same code as before, but replace the big for loop with this:

for(var f in fs){
    if(f['some-attribute'] < 11){
        bins['0 to 10']['attributes']['count'] ++
    } else if(f['some-attribute'] < 21){
        bins['11 to 20']['attributes']['count'] ++
    } else if(f['some-attribute'] < 31){
        bins['21 to 30']['attributes']['count'] ++
    } else if(f['some-attribute'] < 41){
        bins['31 to 40']['attributes']['count'] ++
    } else if(f['some-attribute'] < 51){
        bins['41 to 50']['attributes']['count'] ++
    } else{
        bins['51 to 60']['attributes']['count'] ++
    }
}

Where 'some-attribute' is the field name.

Also I just noticed I had my bins and conditions in opposing orders... I'll edit the original post.

[RachelS]

Josh thanks for your help.

Is this only available in 10.9 version of Enterprise?

Thanks

Rachel

[jcarlson]

It's not even in Enterprise yet, this is only for the latest Dashboards version, which is AGOL-only at the moment. I'm hoping it's coming in 10.9.1, though!

If you're stuck w/ Enterprise, the next best option is to create a field called "bin" and use a field calculation to populate its value.

[RachelS]

Hi Josh,

Yes I'm using Enterprise, I'll have a look at using a field calculation for it.

May thanks

Rachel