0 个投票

Unfortunately, in line four it tells me that I am not passing enough input arguments. I don't quite understand how to fix the error? The code seems to be correct for me. I actually converted the code from python to matlab because in matlab I need the function.
Thanks for your help!
Code:
function e = angle_axis(T,Td)
e = [];
e(1:3) = Td(1:3,end)-T(1:3,end); % -> Mistake
R = Td(1:3, 1:3) * T(1:3, 1:3).';
li = [R(2, 1) - R(1, 2), R(0, 2) - R(2, 0), R(1, 0) - R(0, 1)];
if any(li)
% diagonal matrix case
if trace(R) > 0
% (1,1,1) case
a = zeros(3,0);
else
a = pi/2*(diag(R)+1);
end
else
ln = norm(li);
a = atan2(ln, trace(R)-1)*li/ln;
end
e(3:1) = a;
end

4 个评论
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Torsten
Torsten 2021-12-29
In MATLAB, array indexing starts with 1, i.e. R(0,y) and R(x,0) errors.
Christian Vogel
Christian Vogel 2021-12-29
Thanks for the note! I have corrected the mistake, but I still have the same problem....
Torsten
Torsten 2021-12-29
编辑：Torsten 2021-12-29
Then post your revised code together with the call to "angle_axis" and the error message you get.
And allocating zeros(3,0) also does not make much sense - you get an empty matrix.
Christian Vogel
Christian Vogel 2021-12-29
Thanks for your help!

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 采纳的回答

KSSV
KSSV 2021-12-29

0 个投票

The error is clear. You are trying to run the function by hitting the run button/ F5 key. You need to provide the inputs to the function and then call the function.
T = define your value ;
Td = define your value ;
e = angle_axis(T,Td) % now call the function

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Christian Vogel
Christian Vogel 2021-12-29
Now I have following mistake, after I provide the inputs for the function (refer png)

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更多回答（1 个）

Christian Vogel
Christian Vogel 2021-12-29

0 个投票

That is the "translated" Matlab code:
function e = angle_axis(T,Td)
e = [];
e(1:3) = Td(1:3,end)-T(1:3,end);
R = Td(1:3, 1:3) * T(1:3, 1:3).';
li = [R(3, 2) - R(2, 3), R(1, 3) - R(3, 1), R(2, 1) - R(1, 2)];
if any(li)
% diagonal matrix case
if trace(R) > 0
% (1,1,1) case
a = zeros(3,1);
else
a = pi/2*(diag(R)+1);
end
else
ln = norm(li);
a = atan2(ln, trace(R)-1)*li/ln;
end
e(3:1) = a;
end
That is the python code:
def _angle_axis(T, Td):
e = np.empty(6)
e[:3] = Td[:3, -1] - T[:3, -1]
R = Td[:3, :3] @ T[:3, :3].T
li = np.array([R[2, 1] - R[1, 2], R[0, 2] - R[2, 0], R[1, 0] - R[0, 1]])
if base.iszerovec(li):
# diagonal matrix case
if np.trace(R) > 0:
# (1,1,1) case
a = np.zeros((3,))
else:
a = np.pi / 2 * (np.diag(R) + 1)
else:
# non-diagonal matrix case
ln = base.norm(li)
a = math.atan2(ln, np.trace(R) - 1) * li / ln
e[3:] = a
return e
And when I run the Matlab code, I get following issue (please refer png data)

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Torsten
Torsten 2021-12-29
Where is the call to "angle_axis" ?
You can not just run the function - it expects matrices T and Td. If you don't supply them, it has "not enough input arguments".
Christian Vogel
Christian Vogel 2021-12-29
Sorry my fault! That was stupid of me.
I have following issue, when I run the function (refer png)
Torsten
Torsten 2021-12-29
编辑：Torsten 2021-12-29
In the last line of angle_axis, use
e(1:3) = a
instead of
e(3:1) = a
or whatever is senseful in this context (e(3:1) is empty).

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