sort numbers in txt file with sort gnuwin32, second value priority over first on each line

Question

I'm writing a .bat file to sort a text file with coordinates:

input 
-30.125,10.555
-8.2333,9.00
12.2556,-10
10,10.555
15,20.1
15,25
20,10.555
-10,10.555

requested output:
12.2556,-10
-8.2333,9.00
-30.125,10.555
-10,10.555
10,10.555
20,10.555
15,20.1
15,25

My code:

sort --g --field-separator=, --key=2,1 "input coordinates.txt" > "sortedcoordinates.txt"

Output with my code, as you seen the negative values in the first column are sorted from high to low:

12.2556,-10
-8.2333,9.00
-10,10.555
-30.125,10.555
10,10.555
20,10.555
15,20.1
15,25

Answer 1

You are misinterpreting the usage of the --key option. You must specify a separate --key option for each key. The 2nd value for each option specifies the terminating field. So if each key option is to be a single column, then the start and stop values should match.

sort -g --field-separator=, --key=2,2 --key=1,1 "input coordinates.txt" > "sortedcoordinates.txt"