fsub
Input Stack:| ts2: TimeSeriesExpr | | ts1: TimeSeriesExpr |
|
⇨ |
Output Stack:| (ts1 - ts2): TimeSeriesExpr | | |
|
Floating point subtraction operator. Compute a new time series where each interval has the
value (a - b) where a and b are the corresponding intervals in the input time
series.
| :fsub |
1.0 |
0.0 |
1.0 |
NaN |
NaN |
| Input 1 |
2.0 |
0.0 |
1.0 |
1.0 |
NaN |
| Input 2 |
1.0 |
0.0 |
0.0 |
NaN |
NaN |
Note in many cases NaN will appear in data, e.g., if a node was brought up and started
reporting in the middle of the time window for the graph. This can lead to confusing
behavior if added to a line that does have data as the result will be NaN. Use the
sub operator to treat NaN values as zero for combining with other time
series.
Example subtracting a constant:
Example subtracting two series:
| Before | After |
 |  |
name,requestLatency,:eq,
:sum,
name,requestsPerSecond,:eq,
:max,
(,name,),:by
| name,requestLatency,:eq,
:sum,
name,requestsPerSecond,:eq,
:max,
(,name,),:by,
:fsub
|
