title: Synchronisation of data from different sensor
body: <p>So we have a system which detects the activity of a human, he have multiple sensor on him (accelerometer,etc...) and each sensor learn individually with machine learning algorithm. So a sensor can send : &quot;I think at 80% the man is standing&quot; for example. For now we have made this with dataset synchronised but in real life the sensors are asynchronous and send the data at different time (the clocks are different on each sensor). So the question is how we can make a dataset &quot;synchronised&quot; from a dataset  with empty data.</p>
  <p>Exemple (each 50ms a row):</p>
  <p><a href="https://i.stack.imgur.com/IOIxj.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/IOIxj.png" alt="enter image description here" /></a></p>
  <p>So how can I fill the empty cells by a value to have response from all sensors because we have a fusion function which says when we have a row of data which activity the man is doing.</p>
  <p>I hope you understand what I am searching. I think we need some mathematical function to fill the empty cells like a linear function or other but I need to be sure and I don't find a research report on the web which confirm that or tell me what function to use.</p>