Retrieve X,Y,Z Co-ordinates from CNC Programme

I have gone through matlab code of Laser-assisted direct ink writing of metal which is available file exchange tab, in that by reading the CNC G-codes they are converting into x,y,z data for the tool movement. Particularly, for G02 & G03 Circular Interpolation, he was used the vector method to find the angle of circle/arc. i want to know physical meaning of vector v1 and v2 and what is meaning of phase angle? Please help me.

%if G2 command (CW arc)

elseif command(1) == 2

%determine endpoint

endPos = startPos + command(2:4);

%determine arc angle and radius

v1 = [command(2), command(3)]

v2 = [-command(6), command(5)]

if norm(v1) == 0

arcAngle = 2*pi;

else

arcAngle = 2*acos(v1*transpose(v2)/(norm(v1)*norm(v2)))

end

arcRadius = norm(v2);

%determine initial phase of arc

phase = acos(([-1,0]*[command(5); command(6)])/arcRadius);

if command(6) > 0

phase = 2*pi - phase;

end

%angle increment

dtheta = ds*(arcRadius^2 + (command(4)/arcAngle)^2)^(-1/2);

theta = 0:dtheta:arcAngle;

%define x & y coordinates

array(:,1) = arcRadius*cos(phase - theta) ...

+ startPos(1) + command(5);

array(:,2) = arcRadius*sin(phase - theta) ...

+ startPos(2) + command(6);

%define z values, ensure it has same number of points as x,y

size = numel(theta);

dz = command(4)/(size-1);

array(1,3) = startPos(3);

for i = 2:size

array(i,3) = array(i-1,3) + dz;

end