Non-Sorted nx1 unique values
2 次查看(过去 30 天)
显示 更早的评论
Hello, i am attempting to find repeated values in an nx1 matrix, the catch is that the unique function sorts the data. The data should not be sorted. Ideally i would like the output from my mystery function to be 1 for not repeated and 0 for repeated. Any suggestions?!
input: [1;1;1;2;3;4;5;6;6;7] output:[1;0;0;1;1;1;1;1;0;1]
the idea is that i can multiply the output and the original matrix where the data resides so that duplicate records will show as 0 values, but the first stays!
Thanks again! If you would like me to post another question please let me know!
2 个评论
Image Analyst
2016-12-19
Give a short example of your input and desired output. Why don't you just use unique and histogram(). Are your data integers or floating point values?
采纳的回答
Roger Stafford
2016-12-19
Let x be the given n by 1 vector.
[y,p] = sort(x);
d = diff(y)~=0;
b = [d;true] & [true;d];
b(p) = b;
Then b will be your "ideal" desired result.
8 个评论
Roger Stafford
2016-12-21
@Jan. In William’s original request he states:, “the idea is that i can multiply the output and the original matrix where the data resides so that duplicate records will show as 0 values, but the first stays!” To be able to do such a multiplication (presumably elementwise) the final reordering by “b(p) = b” would be very necessary.
Jan
2017-1-16
@Roger: I meant "The data should not be sorted." Anyway, both methods are included in your solution.
更多回答(1 个)
John BG
2016-12-19
编辑:John BG
2016-12-19
but this code seems to work with any randomly generated sequence.
If it works for noise it works for any deterministic signal, oder?
N=20;
A=randi([-10 10],1,N);
% nA=[1:1:numel(A)]
A
[B,reloc]=sort(A)
% dB=diff(B)
% B(find(dB~=0))
nv=0;
k=1
while k<=numel(B)-1
k=k+1
u0=B(k-1);u1=B(k);
if u0==u1
nv=[nv k]
k=k+1
while B(k-1)==B(k);
k=k+1
end
end
end
nv(1)=[]
B(nv)
for certain sequences there is an overflow message
Index exceeds matrix dimensions.
Error in find_long_bursts (line 17)
while B(k-1)==B(k);
don't worry, sequence
nv
contains the right indices and therefore
B(bv)
is ok.
Just had to do something else, I am cleaning it if Mr Honjas likes the code :) .
if you John BG's answer useful would you please mark it as Accepted Answer?
To any other reader, please if you find this answer of any help, click on the thumbs-up vote link,
thanks in advance for time and attention
John BG
另请参阅
类别
在 Help Center 和 File Exchange 中查找有关 Logical 的更多信息
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!