The forum archives have yielded a lot of excellent help for me over the past few years, but this one I'm afraid I need to post a question on.
I'm currently working in a test lab. I have two different instruments recording high speed data from the same event, and I want to import that data into Excel and chart it in such a way that the data are synchronous and on the same time scale.
The issues are:
1: the two instruments sample at different rates -- one every 4ms exactly, the other at roughly 32ms (plus or minus 1-2ms)
2: the two instruments don't start recording at exactly the same time -- one starts automatically, the other has to be started/stopped by hand
3: when I plot both data streams on a scatter plot, one trace always ends up looking "squished" relative to the other along the independent axis
4: even if I could magically sync the start/stop times of both sensors, they still obviously produce very different amounts of data -- the fast sensor can easily have 3-5 times the number of samples than the slow sensor.
5: each sensor time stamp starts from 0 at the beginning of the recording -- I can't synchronize the sensors to an external realtime clock (oh, I wish!)
Importing the data into Excel is not an issue. I have two columns for each sensor: one containing a timestamp for the datum (starting from 0), and the second containing the datum itself. Each data trace can plot on its own scatter plot with no problems, and I can "stack" the plots vertically on my screen and roughly synchronize them by moving the plots and stretching/shrinking them. But that's a rather crude solution. I really want to be able to put these two data streams into the same scatter plot, synchronized and scaled equally along the independent axis.
I can select a particular row to sync the the two streams by hand -- I don't need any sort of automatic event or shape matching (although that would be a neat trick). And if the best way to do this is to write a VBA macro, I've written some modest VBA for data postprocessing before, so I'm not intimidated by that prospect. But before I start chasing down that rabbit hole, I'm hoping that someone here might know of a better, more efficient way to achieve what I'm looking to do.
I'm currently working in a test lab. I have two different instruments recording high speed data from the same event, and I want to import that data into Excel and chart it in such a way that the data are synchronous and on the same time scale.
The issues are:
1: the two instruments sample at different rates -- one every 4ms exactly, the other at roughly 32ms (plus or minus 1-2ms)
2: the two instruments don't start recording at exactly the same time -- one starts automatically, the other has to be started/stopped by hand
3: when I plot both data streams on a scatter plot, one trace always ends up looking "squished" relative to the other along the independent axis
4: even if I could magically sync the start/stop times of both sensors, they still obviously produce very different amounts of data -- the fast sensor can easily have 3-5 times the number of samples than the slow sensor.
5: each sensor time stamp starts from 0 at the beginning of the recording -- I can't synchronize the sensors to an external realtime clock (oh, I wish!)
Importing the data into Excel is not an issue. I have two columns for each sensor: one containing a timestamp for the datum (starting from 0), and the second containing the datum itself. Each data trace can plot on its own scatter plot with no problems, and I can "stack" the plots vertically on my screen and roughly synchronize them by moving the plots and stretching/shrinking them. But that's a rather crude solution. I really want to be able to put these two data streams into the same scatter plot, synchronized and scaled equally along the independent axis.
I can select a particular row to sync the the two streams by hand -- I don't need any sort of automatic event or shape matching (although that would be a neat trick). And if the best way to do this is to write a VBA macro, I've written some modest VBA for data postprocessing before, so I'm not intimidated by that prospect. But before I start chasing down that rabbit hole, I'm hoping that someone here might know of a better, more efficient way to achieve what I'm looking to do.
