Rotate an array of lines

I need to rotate a line (and posteriorly an array of lines) on a given alpha from a variable coordinate origin ( x,y ). I need to use the command line() and I already tried command rotate() with no luck.

Can some one please help me out? :)

Thanks in advance

[Walter Roberson]

What does it mean to rotate a line "on a given alpha" ?

[Xeio De Sono]

Means that the angle varies in a iterative function:

for i=1:1:45

set(h3,'Visible','off')

h3=line(XXX,YYY) %its a matrix containing all lines I need

rotate(h3,[0 0 1],i); % 'i' is an angle variation, the so called "alpha"

set(h3,'Visible','on')

end

Answer 1

[Jakob Sørensen]

If you for some reason can't get the built in functions to do as you want, you could always try it the old school way (doing the math yourself)...

http://en.wikipedia.org/wiki/Rotation_matrix

Answer 2

[bym]

h = line([2,5],[2,2]);
rotate(h,[0,0,1],45)

[Xeio De Sono]

As I said, I tried rotate() without the result I needed, is there any other way to perform such rotation?

[Jan]

As long as you describe the problems only by "with no luck" and "without the result I needed", it is hard to guess, what you are looking for. It is much more efficient to invest time in answering question, than in guessing, what the question is. So please post more details - by editing the original question, and not as answer or comment. Thanks.

Answer 3

[Xeio De Sono]

Thank you Jan Simon for reminding me this is a tool not a toy. Thank you Jakob Sorensen for reminding me of the old ways. I now have the code that I needed. Its an array of lines that follows a given (x,y,teta) coordinate system. If you see a chance for code improvement please let me know.

 TWR = [ cos(param(3))  -sin(param(3))    param(1);
        sin(param(3))   cos(param(3))    param(2);
        0                          0          1 ]; %tranformation to the world for following (x,y,teta)

 TSR1=[  1  0    0;
       0   1    15;
        0                          0          1 ];
TSR2=[ 0.8660 -0.5    -10;
       0.5   0.8660   10;
        0                          0          1 ];
TSR3=[ 0.8660  0.5    10;
        -0.5   0.8660    10;
        0                          0          1 ];
    %transformation for each sonar
  Sonar1=[0 -8 0 8; 0 alcance(1) alcance(1) alcance(1); 1 1 1 1];
   Sonar2=[0 -8 0 8; 0 alcance(2) alcance(2) alcance(2); 1 1 1 1];
    Sonar3=[0 -8 0 8; 0 alcance(3) alcance(3) alcance(3); 1 1 1 1];

 %cone representing each sonar
  Sf1=TWR*TSR1*Sonar1;
  Sf2=TWR*TSR2*Sonar2; 
  Sf3=TWR*TSR3*Sonar3;
  % execution of the transformations

    Sonares=[ Sf1(1,1) Sf1(1,2) Sf1(2,1) Sf1(2,2); %
              Sf1(1,1) Sf1(1,3) Sf1(2,1) Sf1(2,3); % 3 raios sonar 1
              Sf1(1,1) Sf1(1,4) Sf1(2,1) Sf1(2,4); %
              Sf2(1,1) Sf2(1,2) Sf2(2,1) Sf2(2,2); %%
              Sf2(1,1) Sf2(1,3) Sf2(2,1) Sf2(2,3); %%3 raios sonar 2
              Sf2(1,1) Sf2(1,4) Sf2(2,1) Sf2(2,4); %%
              Sf3(1,1) Sf3(1,2) Sf3(2,1) Sf3(2,2);  %%%
              Sf3(1,1) Sf3(1,3) Sf3(2,1) Sf3(2,3);  %%%3 raios sonar 3
              Sf3(1,1) Sf3(1,4) Sf3(2,1) Sf3(2,4);
              Sf1(1,1) (Sf1(1,3)+Sf1(1,4))/2 Sf1(2,1) (Sf1(2,3)+Sf1(2,4))/2;
              Sf1(1,1) (Sf1(1,2)+Sf1(1,3))/2 Sf1(2,1) (Sf1(2,2)+Sf1(2,3))/2;
              Sf2(1,1) (Sf2(1,3)+Sf2(1,4))/2 Sf2(2,1) (Sf2(2,3)+Sf2(2,4))/2;
              Sf2(1,1) (Sf2(1,2)+Sf2(1,3))/2 Sf2(2,1) (Sf2(2,2)+Sf2(2,3))/2;
              Sf3(1,1) (Sf3(1,3)+Sf3(1,4))/2 Sf3(2,1) (Sf3(2,3)+Sf3(2,4))/2;
              Sf3(1,1) (Sf3(1,2)+Sf3(1,3))/2 Sf3(2,1) (Sf3(2,2)+Sf3(2,3))/2]; %%%array of lines

   line([Sonares(1,1) Sonares(1,2)],[Sonares(1,3) Sonares(1,4)])
   line([Sonares(2,1) Sonares(2,2)],[Sonares(2,3) Sonares(2,4)])
   line([Sonares(3,1) Sonares(3,2)],[Sonares(3,3) Sonares(3,4)])
   line([Sonares(4,1) Sonares(4,2)],[Sonares(4,3) Sonares(4,4)])
   line([Sonares(5,1) Sonares(5,2)],[Sonares(5,3) Sonares(5,4)])
   line([Sonares(6,1) Sonares(6,2)],[Sonares(6,3) Sonares(6,4)])
   line([Sonares(7,1) Sonares(7,2)],[Sonares(7,3) Sonares(7,4)])
   line([Sonares(8,1) Sonares(8,2)],[Sonares(8,3) Sonares(8,4)])
   line([Sonares(9,1) Sonares(9,2)],[Sonares(9,3) Sonares(9,4)])

   line([Sonares(10,1) Sonares(10,2)],[Sonares(10,3) Sonares(10,4)])
   line([Sonares(11,1) Sonares(11,2)],[Sonares(11,3) Sonares(11,4)])
   line([Sonares(12,1) Sonares(12,2)],[Sonares(12,3) Sonares(12,4)])
   line([Sonares(13,1) Sonares(13,2)],[Sonares(13,3) Sonares(13,4)])
   line([Sonares(14,1) Sonares(14,2)],[Sonares(14,3) Sonares(14,4)])
   line([Sonares(15,1) Sonares(15,2)],[Sonares(15,3) Sonares(15,4)])

Answer 4

[Sean de Wolski]

doc hgtransform
doc makehgtform

and

Doug