Count how many times a value is present in a vector
in [Matlab]
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From: Thijs on 15 Jul 2010 08:04 Hello, I have a rowvector with a length of app. 300 that is filled with integer values ranging from 1 to app. 13000. Therefore, most values (out of the range of 1 to 13000) will not be present in the vector, some values will be unique, but other values are present multiple times. I am not really interested in the values that occur only once in the vector, but I do want to know which values occur more than once and also how many times these values occur. In short, I have two questions: - How can I check which values occur more than once in my vector? - How can I see how many occurences (of the values out of my first question) there are? Thanks in advance for the help.
From: Thijs on 15 Jul 2010 08:53 Ok, I have solved one of my two questions myself by: x = length(v1)-length(unique(v1)) Now only one question remains, how can I find out which numbers were not unique in the rowvector v1? Thanks. Thijs "Thijs " <t.denhamer(a)student.tudelft.nl> wrote in message <i1mtfl$73i$1(a)fred.mathworks.com>... > Hello, > > I have a rowvector with a length of app. 300 that is filled with integer values ranging from 1 to app. 13000. Therefore, most values (out of the range of 1 to 13000) will not be present in the vector, some values will be unique, but other values are present multiple times. I am not really interested in the values that occur only once in the vector, but I do want to know which values occur more than once and also how many times these values occur. > > In short, I have two questions: > > - How can I check which values occur more than once in my vector? > - How can I see how many occurences (of the values out of my first question) there are? > > Thanks in advance for the help.
From: Sean on 15 Jul 2010 09:10 "Thijs " <t.denhamer(a)student.tudelft.nl> wrote in message <i1n0bi$9cn$1(a)fred.mathworks.com>... > Ok, I have solved one of my two questions myself by: > > x = length(v1)-length(unique(v1)) > > Now only one question remains, how can I find out which numbers were not unique in the rowvector v1? > > Thanks. > Take a peak at the 2nd/3rd outputs from unique(). Function accumarray() will also help.
From: Sean on 15 Jul 2010 09:20 "Thijs " <t.denhamer(a)student.tudelft.nl> wrote in message <i1n0bi$9cn$1(a)fred.mathworks.com>... > Ok, I have solved one of my two questions myself by: > > x = length(v1)-length(unique(v1)) > > Now only one question remains, how can I find out which numbers were not unique in the rowvector v1? > You could do this all in one step with histc().
From: Matt J on 15 Jul 2010 09:27
"Thijs " <t.denhamer(a)student.tudelft.nl> wrote in message <i1mtfl$73i$1(a)fred.mathworks.com>... > In short, I have two questions: > > - How can I check which values occur more than once in my vector? > - How can I see how many occurences (of the values out of my first question) there are? ============= Values=1:13000; N=histc(YourVector,Values); ValuesOccuringMoreThanOnce=Values(N>1); NumberOfOccurences=N(N>1); |