If statement is not working

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Mehmet Volkan Ozdogan
评论： Walter Roberson 2019-7-18
Hi,
angle1 variable has data from 0 to 90 but is statemant is not working. For example if angle1>=3 and if angle1>=53 give same results.
I do not understand what is the problem.
Thank you...
angle1=abs(atand((newVar(:,3)-newVar5(:,3))./(newVar(:,1)-newVar5(:,1))))
[~,idx5] = pdist2(newVar2,newVar,'euclidean','smallest',1); % indices of nearest * for EACH X
newVar6=newVar2(idx5, :);
angle2=abs(atand((newVar6(:,3)-newVar5(:,3))./(newVar6(:,1)-newVar5(:,1))))
d2=pdist2(newVar5,newVar6);
dy=d2(:)
if angle1>=19
dxs=(sind(angle1).*dx);
dys=(sind(angle2).*dy);
def=dxs-dys
else
dxs=(cosd(angle1).*dx);
dys=(cosd(angle2).*dy);
def=dxs-dys
end
  2 个评论
Mehmet Volkan Ozdogan
Mehmet Volkan Ozdogan 2019-7-18
newVars is a matrice 100x3. they are coordinates...
Thanks

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Walter Roberson
Walter Roberson 2019-7-18
In MATLAB, the test
if A > B
is treated the same as if it had been
if all(A(:) > B(:))
Your angle1 is a vector. Some of the elements of it are >= 19, but not all >= 19, so the if is not considered to be true.
When you are working with non-scalars, you should get in the habit of explicitly coding all() or any() to indicate which test you intend.
... But what you probably really need is to learn about logical indexing: see https://blogs.mathworks.com/steve/2008/01/28/logical-indexing/
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Mehmet Volkan Ozdogan
Mehmet Volkan Ozdogan 2019-7-18
Thank you for your advices Mr. Roberson
I have now understand what you mean and solved my problem
for i=(1:100)
if all(angle1(i)>=19)
dxs(i)=(sind(angle1(i)).*dx(i));
dys(i)=(sind(angle2(i)).*dy(i));
else
dxs(i)=(cosd(angle1(i)).*dx(i));
dys(i)=(cosd(angle2(i)).*dy(i));
end
def(i)=dxs(i)-dys(i)
end
Walter Roberson
Walter Roberson 2019-7-18
Example:
Mask = x> 5;
Y(Mask) = sin(x(Mask))
Y(~Mask) = cos(x(~Mask))

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