what does it mean

 for k = (i-1):-1:1

Answer 1

[Image Analyst]

When you say

for k = start : step : stop

the first expression, (i-1) in your case, will be the first/starting value of the loop iterator k. Then the next iteration k will be start+step, or i-1-1 = i-2 in your case. It keeps going until it gets to the "stop" value or goes past it (i.e., goes above it if the step is positive, or below it if the step value is negative). This is basic stuff. Please read the getting started section of the help for more essential information.

Answer 2

[rantunes]

Hey

You can answer your question by running:

for k = (i-1):-1:1;
   k
end

Greets

[rantunes]

without the semi-colon in the end of the line of the for