Computing energy consumption from power measurements

[ejhusom]

Hi,

I'm using Scaphandre to monitor the power usage of a certain process. My goal is to simply compute the energy consumption (in Joules) for this process running for a given duration. However, I'm not sure if I fully understand the power measurements coming from Scaphandre. Are they the current power level at the time of measuring? So in order to compute the energy consumption $E$ over a duration $t$ with $N$ number of power measurements $P_n$, I would have to compute the average power level $\hat{P}$ and multiply by the duration $t$:

$$E =\frac{t}{N} \sum_{n=0}^N P_n$$

Or in Python:

energy_consumption = duration * power_measurements.sum() / len(power_measurements)

This would then be independent of the time between measurements, but the shorter time I have, the more accurate the readings will be?

I apologize for asking very basic questions, but I would like to confirm that this is correct :)

[JJ]

Well, depends on sampling time; the more sampling time is adjusted to your running time with no left-over the more accurate it will be.