MATLAB Answers

Store data in cell arrays

216 views (last 30 days)
Ricky
Ricky on 17 Jul 2013
Hello Everyone,
I know the question below is quite stupid but please help as I am not able o find a solution for it. This is a sample array that I have. I want to check the second column of this. The places where I get 1 should be stored together in cell array. As I start scanning the first 4 values get stored in cell array 1 then as the value in second column is 0 I do not store it . Again when I get 1 I should store but in cell array 2. The number of values that I will get is not fixed.
26.81267 1
26.82500 1
26.83733 1
26.86200 1
37.41933 0
37.40700 0
37.39466 0
37.38233 0
27.08400 1
27.07167 1
27.05933 1
27.04700 1
27.02233 1

Answers (4)

the cyclist
the cyclist on 17 Jul 2013
Edited: the cyclist on 17 Jul 2013
If A is your original array, then
C{1} = A(A(:,2)==1,:);
is a one-element cell array that stores the 9 rows with a zero.
If you only wanted to store the first column, then
C{1} = A(A(:,2)==1,1);
instead.
  1 Comment
Ricky
Ricky on 17 Jul 2013
actually I want to store them in 2 cell arrays the first 4 elements go in cell array 1 and last 5 elements go in cell array 2

Sign in to comment.


Andrei Bobrov
Andrei Bobrov on 17 Jul 2013
Edited: Andrei Bobrov on 18 Jul 2013
a =[26.81267 1
26.82500 1
26.83733 1
26.86200 1
37.41933 0
37.40700 0
37.39466 0
37.38233 0
27.08400 1
27.07167 1
27.05933 1
27.04700 1
27.02233 1];
l = [true;diff(a(:,2))~=0];
l(l) = a(l,2);
ll = cumsum(l);
out = accumarray(ll(a(:,2)>0),a(a(:,2)>0,1),[],@(x){x});
OR
l = [true;diff(a(:,2))~=0];
d = diff([find(l);size(a,1)+1]);
out = mat2cell(a(a(:,2)>0,1),d(a(l,2)>0),1);

Azzi Abdelmalek
Azzi Abdelmalek on 17 Jul 2013
Edited: Azzi Abdelmalek on 17 Jul 2013
i2=[1 1 0 0 1 1 1 1 0 0 1 1 0 0 0 1 1 0 1];
a=[i2(1) diff(i2)];
idx1=find(a==1);
idx2=find(a==-1);
if numel(idx2)<numel(idx1)
idx2(end+1)=numel(a)+1;
end
out=arrayfun(@(x1,x2) i2(x1:x2),idx1,idx2-1,'un',0)
  5 Comments
Evan
Evan on 17 Jul 2013
A good majority of my answers rely on arrayfun/cellfun as well (also regexp/regexprep). I think, for me, it's an unfortunate symptom of spending too much time playing Cody.

Sign in to comment.


Swapnali Gujar
Swapnali Gujar on 17 Jul 2013
You can try below code. This code will give you output as a cell whose first 2 cells will have names as "cell_array1" and "cell_array2", since there are 2 times when 1s appear in your input array in continuation (i.e. first 4 times 1s and next 5 times 1s). Below each column name, you will find respective 1s of each scan.
clc
clear all;
arr = [26.81267 1;
26.82500 1;
26.83733 1;
26.86200 1;
37.41933 0;
37.40700 0;
37.39466 0;
37.38233 0;
27.08400 1;
27.07167 1;
27.05933 1;
27.04700 1;
27.02233 1;
]
size_arr = size(arr);
j=0;
scan = 0;
for i=1:length(arr)
if((arr(i,2)) == 1.000)
j=j+1;
scan=j;
if (i<length(arr)) && (arr((i+1),2) == 1.000)
j = j-1;
end
cell_arr{scan} = strcat('cell_array',num2str(scan)); %creates numbered cell arrays
end
end
%===== Now start storing the values into the cell arrays.
index=1;
columns = length(cell_arr)
k=1;
for i =1:length(arr)
if(((arr(i,2)) == 1.000)) && (k<=columns)
cell_arr(index+1,k) = num2cell(arr(i,2));
index = index+1;
elseif (arr(i,2) == 0.000)&&((arr(i+1,2)) == 1.000)
k = k+1;
index=1;
end
end
%end of file
This will give you output as cell_arr =
'cell_array1' 'cell_array2'
[ 1] [ 1]
[ 1] [ 1]
[ 1] [ 1]
[ 1] [ 1]
[] [ 1]
You may need further processing to access these columns separately as per your need.

Community Treasure Hunt

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

Start Hunting!

Translated by