very good code?thank you?

"jason " <mcmains.1@osu.edu> wrote in message <gabct5$a7u$1@fred.mathworks.com>...
> for those interested in offset lines, I found some code that seems to work
>
> function [X,Y]=LineOffset(x,y,width)
> OFFSET=width/2;
> XX0=[x(1)-diff(x(1:2)) x x(end)+diff(x(end-1:end))];
> YY0=[y(1)-diff(y(1:2)) y y(end)+diff(y(end-1:end))];
> XOffset=zeros(size(x));
> YOffset=zeros(size(x));
> IsPossible=1;
> for i = 2: length(x)+1;
> YVal = -1*OFFSET;
> [TH, R]=cart2pol(XX0-XX0(i),YY0-YY0(i));
> TH_Spin=TH(i-1)-pi;
> [XNew, YNew]=pol2cart(TH-TH_Spin, R);
> dX=diff(XNew(i:i+1));
> dY=diff(YNew(i:i+1));
> % There are 9 conditions for dY & dX
> XVal = 0;
> if dX<=0 && dY==0
> IsPossible=0; % not a good definition
> else
> if dX == 0;
> if dY > 0;
> XVal = OFFSET;
> else %dY < 0
> XVal = -1*OFFSET;
> end
> elseif dX > 0;
> slope = dY/dX;
> if dY ~= 0;
> intercept = -1*OFFSET / (cos(atan(abs(slope))));
> XVal=(YVal-intercept)/slope;
> end
> else %dX < 0
> slope = dY/dX;
> intercept = OFFSET / (cos(atan(abs(dY/dX))));
> XVal=(YVal-intercept)/slope;
> end
> end
> [TH0, R0]=cart2pol(XVal,YVal);
> [XTemp,YTemp]=pol2cart(TH0+TH_Spin,R0);
> XOffset(i-1)=XTemp+XX0(i);
> YOffset(i-1)=YTemp+YY0(i);
> end
>
> XOffset2=(x-XOffset)+x;
> YOffset2=(y-YOffset)+y;
>
> X=[XOffset fliplr(XOffset2) XOffset(1)];
> Y=[YOffset fliplr(YOffset2) YOffset(1)];
> if ~IsPossible
> X=[];
> Y=[];
> end
>
>
> please post if you can figure out any improvements to this code.
>
> Thanks
> Jason