I am trying to visualise a sparse dataset but am finding it hard to fit it into the standard categories of charts. I'm a developer building with Google Charts and I really want to stick with that product.
The data set is the total count of "alerts" per day coming from a set of 2,000 devices. On most days some of the devices have problems and raise a few alerts. I want to display a chart so that an administrator can easily see which devices are having problems recently and be able to look back in time over previous days/weeks/months.
- "Most" days = almost every day.
- "Some" devices = perhaps 100-1000 (per day)
- "A few" alerts = perhaps 1 to 100 (per device per day) occasionally much higer.
I tried putting this on a column or line chart, but it seems to end up needing 2,000 columns mostly with empty data - and results in unworkably large dataset (I have to fill the entire table with missing data points) or a terrible UI, or a crashed browser.
The raw row data is really simple, just three columns:
date, device id, number of alerts
but the sparsity over time, and the fact that different devices pop up on different days, means I can't figure out how to map it to a chart.
I was thinking a stacked column chart would be ideal, but again technically the graphing system needs a consistent set of columns on every day.
It feels like I need a kind of daily stacked histogram, to collate by #of alerts? Or a threshold...
(BTW I've tagged it google-spreadsheet because it's the same charts, but I'm not using the spreasheets, I've made a data-provider)
(BTW2 I'm new to this exchange. I may post a more technical question on SO about the programming behind Google Charts - if that's all that's holding me up, but I was hoping for some visualisation inspiration here!)