Exclusion

Docs > Dashboards > Functions > Exclusion

Exclude null

Function	Description	Example
`exclude_null()`	Remove groups with N/A tag values from your graph or top list.	`exclude_null(avg:system.load.1{*} by {host})`

For example, say you have a metric with two tags: account and region. account has three possible values (prod, build and N/A) while region has four possible values (us-east-1, us-west-1, eu-central-1, and N/A).

When you graph this metric as a timeseries, you would have 3 x 4 = 12 lines on your graph. Applying exclude_null() removes lines with tag combinations containing any N/A values, leaving you with 2 x 3 = 6 groups.

Clamp

Function	Description	Example
`clamp_min()`	Set any metric values under a threshold value to equal that value.	`clamp_min(avg:system.load.1{*}, 100)`
`clamp_max()`	Set any metric values over a threshold value to equal that value.	`clamp_max(avg:system.load.1{*}, 100)`

Add a threshold value. The clamp_min() sets all datapoints below the threshold to equal that value, while clamp_max() limits datapoints above the threshold.

Note: clamp_min(values, threshold) and clamp_max(values, threshold) sets any NaN in values to threshold.

To avoid this behavior, apply the default_zero() before the clamp_min() / clamp_max() function.

Cutoff

Function	Description	Example
`cutoff_min()`	Replace metric values under a threshold value with NaN.	`cutoff_min(avg:system.load.1{*}, 100)`
`cutoff_max()`	Replace metric values over a threshold value with NaN.	`cutoff_max(avg:system.load.1{*}, 100)`

Add a threshold value. The cutoff_min() replaces all metric values lower than this threshold value with NaN, while cutoff_max() replaces all metric values higher than this threshold value with NaN. The cutoff functions do not replace values that are equal to the threshold value.

Tip: For both the clamp and cutoff functions, it may be helpful to see the threshold value you have chosen. You can set a horizontal marker in Dashboards to indicate this value.