Repeatability problem and gagerr

Dear experts, I created a really simple GUI to perform measurements on plots. Now i want to evaluate the repeatability of this tool using gagerr but i'm not and statistician and i have never before used this function.

That's what i get:

a) I performed a test with 10 student using this GUI, they measured some distances on the plots using ginput.

b) The test consist of 4 plots analyzed in a loop of 120 repetitions (that means that each plot was measured 30 times by each user)

at the end i have 300 measurments for each plot.

The question is: how should i arrange the data for gagerr? according the help, gagerr inputs are (y,{part,operator}) but i dont undertand how the matrix should be arranged.

Somebody have experience with gagerr?, or maybe there is another better method to perform this analysis?

Thanks in advance for your help