Hello everyone!
This is my first visit here and I hope to get an answer on something I am trying to get done in Excel. A look through other posts have also made me realise how much more can be done in Excel than I ever thought...
Here's my situation: I am a physiologist collecting data from an ultrasound machine on the diameter of blood vessels. When my experiment is finished I end up with a file that has four columns and up to 23,000 rows. The important columns are the first two and they are a time column (format: hh:mm:ss), and a diameter column. The frequency of measurements is such that for every second you end up with 25 rows, but unfortunately, sometimes you end up with 24 rows in a second. What I need to do is to get average diameters for every second and for every ten seconds.
What I have done so far is to use "if" statements to give all the rows within a second a marker (so that "10:25:01" is "1", "10:25:02" is "2", etc.), and then average the diameters for each of these markers (using more "if" statements to add the diameters within a marker and divide by the "count" of the marker). Having done this I end up with a column where I get the average diameters I need, but with 24 blank cells in between. That's where the problems begin.
Problem 1: I get an error message saying that a 2D plot can only contain up to 16,000 points for each series. This is despite filtering the column with the results to only display the "nonblanks" which are a lot less than 16,000.
Problem 2: When I average the one-second intervals to get ten-second intervals, and then try to filter this column to only disply "nonblanks" my averages are messed up because the source column has changed as well.
My questions:
1. Is there any way to average for every so many rows? If yes, is there a way to quickly have an automatic check to see if every second has 25 rows to it? If I cannot is there a way I can work around the possibility of having a few seconds that will contain a different number of rows?
2. When you have a column with blank cells, is it possible to copy it and then paste only the nonblank cells? (this could prevent the error message I get and which pauses my macro).
I appreciate this is a long, and possibly unclear explanation so I will not be too surprised if you ignore me, but thanks in advance anyway.
All the very best,
George
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