how to rotate a matrix 5x4 by 45° around the origin (0,0) ?
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Suppose I have a matrix M of 5x4 dimension (this is represent an image) :
M =[3 4 8 9;
1 6 7 3;
9 8 3 1;
1 2 2 0;
7 2 3 5];
I would like to rotate it around the origin (0,0) with an angle of 45°.
From what I have found on the net , I have to multiply M by Rotation Matrix R is as follow :
R = [ cosd(45) -sind(45);
Now do I simply multiply M by R and get a rotated matrix ??? like this :
rotM = R*M
I think I will have a problem of dimensions ? please how to rotate a matrix 5x4 by 45° around the origin (0,0)?
PS: imrotate, rot90, flip* and rotate is not suitable here, thank you in advance.
回答 (1 件)
Walter Roberson 2015 年 5 月 16 日
Use matrix multiplication, the * operator, not the .* operator.
Remember that in MATLAB, sin() and cos() take radians as the argument, not degrees. You can use sind() and cosd() for degrees.