How to make matlab count

20 Ansichten (letzte 30 Tage)
Rainaire Hansford
Rainaire Hansford am 11 Jun. 2019
Hello Matlab community,
I wented to know is there a way to create a code to count how many times a number ouccers in a given matrix.
For example I would like to input:
x=input('Numeber')
=[1 2 3 4 5
1 2 3 5 6
7 2 4 3 5]
Is there a way for Matlab to count how many of each number has occured.
Please provide example Thank you so much.

Akzeptierte Antwort

madhan ravi
madhan ravi am 11 Jun. 2019
Bearbeitet: madhan ravi am 11 Jun. 2019
"Is there a way for Matlab to count how many of each number has occured."
The below gives the number of counts of each unique elements in the matrix:
x =[1 2 3 4 5
1 2 3 5 6
7 2 4 3 5]
[uv,~,idx] = unique(x);
n = accumarray(idx(:),1);
% or
n = histc(x(:),uv);
% or
n = sum(x(:).' == uv,2);
Result = [uv,n] % uv - unique elements in the matrix & n - number of times each unique elements appear
Gives:
Result =
1 2
2 3
3 3
4 2
5 3
6 1
7 1
>>

Weitere Antworten (4)

Alex Mcaulley
Alex Mcaulley am 11 Jun. 2019
A =[1 2 3 4 5
1 2 3 5 6
7 2 4 3 5];
x=input('Number')
sum(A(:) == x)

Star Strider
Star Strider am 11 Jun. 2019
One way is to use the nnz (link) function with a logical vector:
x = 5
M=[1 2 3 4 5
1 2 3 5 6
7 2 4 3 5]
Count = nnz(M == x)
producing:
Count =
3

Steven Lord
Steven Lord am 11 Jun. 2019
If you want the frequency of one particular element from the matrix, use the techniques madhan ravi, Alex Mcaulley, and Star Strider have given.
If you want just the counts for each unique element, use histcounts.
If you want a picture of the frequency data, use histogram. The graphics object histogram returns also has the bin count information in its properties, but if you don't need the picture I would use histcounts and skip the cost (in time and memory) of creating the picture.
  4 Kommentare
madhan ravi
madhan ravi am 12 Jun. 2019
Very true :)
Rainaire Hansford
Rainaire Hansford am 17 Jun. 2019
Thanks Steven when I get the chance I would like to use histogram. But can you show me how am I to use it in a code like the one above.

Melden Sie sich an, um zu kommentieren.


Rainaire Hansford
Rainaire Hansford am 17 Jun. 2019
You guys are awesome.
I really wanted the first for this project but the rest of youll are great thank you.

Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by