If I a data file with 3 columns the first being the x cordinates second being the y cordinates and the third being the z.
So If I have
How would I run a loop that goes through Data(:,2) and finds where the y values have changed sign and stores that position. So in my example it would detect the first change in sign from 0.08 to -0.01 (4th position of -0.01) the second change in sign at-0.06 and 0.02 (7th position of 0.02) the third sign change at 0.03 -0.05 (9th position of -0.05) which shows they have passed through y=0 and store those positions as a new column
I hope that makes sense and any help would be appreciated .