Hello Team,
First of all I would like to thank you guys for such a useful aggregation engine available in browser.
Keep up the good work.
I would like to discuss the bug that I have found in perspective core engine.

I am rendering perspective-viewer as follows:

<perspective-viewer 
        style="height: 500px; width: 1000px;" 
	columns='["count"]' 
        row-pivots='["section1", "section2"]' /> 

In all the below scenarios perspective-viewer configs remains the same.

Scenario 1

Lets assume I have following data

[
	{
		section1: '100',
		section2: '1',
		count: 5
	},
	{
		section1: '101',
		section2: '2',
		count: 7
	},
	{
		section1: 'A',
		section2: 'B',
		count: 13
	},
]

It works as expected and display aggregation result as following:

Irrespective of data orde, it works correctly as expected.

Scenario 2

Lets assume following data for this scenario:

[
	{
		section1: '10000',
		section2: '1',
		count: 5
	},
	{
		section1: '101',
		section2: '2',
		count: 7
	},
	{
		section1: 'A',
		section2: 'B',
		count: 13
	},
]

Generating following view:

The last data entry which is

 {
	section1: 'A',
	section2: 'B',
	count: 13
},

is not rendered as expected. Top level label, ie section1: A, is missing and also its section2 key is merged with top level label 101.

Scenario 3

Now lets assume the following data:

[
	{
		section1: '10000',
		section2: '10000',
		count: 5
	},
	{
		section1: '101',
		section2: '2',
		count: 7
	},
	{
		section1: 'A',
		section2: 'B',
		count: 13
	},
]

We get following view:

Now both A and B are missing.
Count value of Count value of 101 |_ 2 is 20, which is also incorrect.

Scenario 4

Now lets decrease first object's section1 and section2 below 10000.

[
	{
		section1: '9999',
		section2: '9999',
		count: 5
	},
	{
		section1: '101',
		section2: '2',
		count: 7
	},
	{
		section1: 'A',
		section2: 'B',
		count: 13
	},
]

Now it seems to work fine as expected
So only values greater than and equal to 10000 are affected and not displayed.

Scenario 5

Lets make keys with alphabetic values as the first record in array.

[
	{
		section1: 'A',
		section2: 'B',
		count: 13
	},
	{
		section1: '10000',
		section2: '10000',
		count: 5
	},
	{
		section1: '10001',
		section2: '10000',
		count: 6
	},
	{
		section1: '10000',
		section2: '10002',
		count: 8
	},
	{
		section1: '101',
		section2: '2',
		count: 7
	},
]

Mysteriously this time as well it is working fine.

Can you please fix this issue as this has serious impact on users.