MATLAB: How to write a loop for finding similar values in the first column and then sort them in a way corresponding values in a same row sort according to the first column

Question

I have three columns of data including longitudes, latitudes and gravities respectively. The Matrix has 6882 rows in which after 31 rows longitudes are repeating. I would like to write a loop in a way to find similar longitudes in the first column and then sort longitudes in an ascending order. Since every row (including a longitude, latitude and gravity) belongs to one point, when I find similar longitudes and sort them in the first column I need corresponding data for each point in the second and third columns arrange according to the first column too.

Answer 1

How about using the second output of sort to re-order the rows, or better yet: use sortrows. No need for any loop if you need to sort values.