Iterate over matlab cell - matlab

I manage to do a 10 fold and store the data into a cell and my cell has the following structure:
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
[135x5 double] [15x5 double]
here is a small snapshot of what data is in this cell, let say we assign this cell in to a variable cell here is the cell{1,1} - This is actually Iris data
5.1000 3.3000 1.7000 0.5000 1.0000
6.8000 3.2000 5.9000 2.3000 3.0000
5.0000 2.3000 3.3000 1.0000 2.0000
7.4000 2.8000 6.1000 1.9000 3.0000
6.5000 3.2000 5.1000 2.0000 3.0000
4.8000 3.4000 1.9000 0.2000 1.0000
cell{1,2}
7.2000 3.2000 6.0000 1.8000 3.0000
6.1000 2.6000 5.6000 1.4000 3.0000
6.4000 2.9000 4.3000 1.3000 2.0000
6.8000 3.0000 5.5000 2.1000 3.0000
6.1000 2.8000 4.0000 1.3000 2.0000
Now I am trying to iterate over each of the row and anyalze the data in first column Cell{1,1}, Cell{1,2)... How can I do that? What is the technique to iterate over cell?

Does this cut-down example solve your problem?
Z = cell(2, 2);
Z{1, 1} = rand(8, 5); Z{1, 2} = rand(2, 5);
Z{2, 1} = rand(8, 5); Z{2, 2} = rand(2, 5);
X = cell2mat(Z(:, 1));
XFirstCol = X(:, 1);
I use cell2mat to concatenate all the matrices in the first column of your cell array into one big matrix, and then the last line just grabs the first column of that matrix.
If you were instead asking how to loop over a cell array, well, you do it the same way as over a numeric array, but using curly braces to index the elements of the cell array ie:
for i = 1:2
CurrentCell = Z{i, 1};
FirstColumnOfCurrentCell = CurrentCell(:, 1);
end
Or you could combine those two lines into: FirstColumnOfCurrentCell = Z{i, 1}(:, 1);
A final point, don't use cell as the name of a variable. This is not good practice, since cell is also the name of an in-built matlab function

Related

Save cell with numbers to text file

I have cell arrays A and B with different lengths and numbers.
A={1:0.5:5;1:0.5:2};
B={1:0.5:6;1:0.5:9};
C= [A;B];
I want to combine these cell arrays into a cell array C, which would then look like this:
C =
4×1 cell array
{1×9 double}
{1×3 double}
{1×11 double}
{1×17 double}
Then, I want to save this into a text file, that should look like this:
1.0000 1.5000 2.0000 2.5000 3.0000 3.5000 4.0000 4.5000 5.0000
1.0000 1.5000 2.0000
1.0000 1.5000 2.0000 2.5000 3.0000 3.5000 4.0000 4.5000 5.0000 5.5000 6.0000
1.0000 1.5000 2.0000 2.5000 3.0000 3.5000 4.0000 4.5000 5.0000 5.5000 6.0000 6.5000 7.0000 7.5000 8.0000 8.5000 9.0000
So far, I have only found code for text or same size arrays. This is my attempt, which doesn't work:
fid = open('filename.txt', 'wt');
fprintf(fid, '%f',C{:})
close(fid)
I believe the problem might be in the format you're specifying for the fprintf, as I believe using only '%f' will print one number on each row.
One way to do this would then be:
fid = fopen('filename.txt', 'wt');
for i = 1:length(C)
fmt = repmat('%f ',size(C{i})); % this only adds one whitespace in between numbers
fmt = [fmt,'\n']; % remember to add a new line
fprintf(fid,fmt,C{i});
end
fclose(fid);

Matlab - Plot from double data

From an N x 3 matrix with values in third column only having the 4 values 1, 2, 3 & 4, I have to create a bar plot as well as a line plot showing the growth rate for each row (second column values). First row values are called 'Temperature', second 'Growth rate' and third 'Bacteria type'
As of right now my line plot does not work when removing rows with one of the four values in the third column. The matrix could look something like this
39.1220 0.8102 1.0000
13.5340 0.5742 1.0000
56.1370 0.2052 1.0000
50.0190 0.4754 1.0000
24.2970 0.8615 1.0000
37.1830 0.8513 1.0000
59.2390 0.0584 1.0000
45.7840 0.6254 1.0000
51.9480 0.3932 1.0000
42.3400 0.7371 1.0000
25.3870 0.8774 1.0000
57.1870 0.3880 2.0000
37.4580 0.7095 2.0000
46.4190 0.6431 2.0000
38.8380 0.7034 2.0000
11.2930 0.1214 2.0000
32.3270 0.6708 2.0000
42.3150 0.6908 2.0000
36.0600 0.7049 2.0000
28.6160 0.6248 2.0000
56.8570 0.3940 2.0000
51.4770 0.5410 2.0000
52.4540 0.5127 2.0000
28.6270 0.6248 2.0000
39.6590 0.7021 2.0000
53.6280 0.4829 2.0000
56.6750 0.4029 2.0000
43.4230 0.6805 2.0000
20.3390 0.4276 2.0000
42.6930 0.6826 2.0000
13.6030 0.2060 2.0000
30.3360 0.6497 2.0000
43.3470 0.6749 2.0000
56.6860 0.3977 2.0000
50.5480 0.5591 2.0000
34.2270 0.6929 2.0000
47.8370 0.6136 2.0000
30.8520 0.6593 2.0000
51.3290 0.5050 3.0000
29.5010 0.7789 3.0000
34.8950 0.8050 3.0000
44.7400 0.6884 3.0000
51.7180 0.4927 3.0000
40.4810 0.7621 3.0000
38.7370 0.7834 3.0000
26.3020 0.7379 3.0000
32.8210 0.8072 3.0000
45.6900 0.6684 3.0000
54.2200 0.4058 3.0000
46.0430 0.6611 3.0000
10.9310 0.2747 3.0000
43.7390 0.7043 3.0000
31.9250 0.7948 3.0000
31.8910 0.7954 3.0000
15.8520 0.4592 3.0000
50.7340 0.5237 3.0000
26.2430 0.7305 3.0000
22.3110 0.6536 3.0000
14.7690 0.1796 4.0000
17.3260 0.2304 4.0000
41.5570 0.3898 4.0000
52.9660 0.2604 4.0000
58.7110 0.1558 4.0000
And my code is as follows, with data being the matrix (double)
function dataPlot(data)
%1xN matrix with bacteria
A=data(:,3);
%Number of different bacterias is counted, and gathered in a vector
barData = [sum(A(:) == 1), sum(A(:) == 2), sum(A(:) == 3), sum(A(:) == 4)];
figure
bar(barData);
label = {'Salmonella enterica'; 'Bacillus cereus'; 'Listeria'; 'Brochothrix thermosphacta'};
set(gca,'xtick',[1:4],'xticklabel',label)
set(gca,'XTickLabelRotation',45)
ylabel('Observations')
title('Destribution of bacteria')
%The data is divided into four matrices based on the four different bacterias
%Salmonella matrix
S=data;
deleterow = false(size(S, 1), 1);
for n = 1:size(S, 1)
%For column condition
if S(n, 3)~= 1
%Mark line for deletion afterwards
deleterow(n) = true;
end
end
S(deleterow,:) = [];
S=S(:,1:2);
S=sortrows(S,1);
%Bacillus cereus
Ba=data;
deleterow = false(size(Ba, 1), 1);
for p = 1:size(Ba, 1)
%For column condition
if Ba(p, 3)~= 2
%Mark line for deletion afterwards
deleterow(p) = true;
end
end
Ba(deleterow,:) = [];
Ba=Ba(:,1:2);
Ba=sortrows(Ba,1);
%Listeria
L=data;
deleterow = false(size(L, 1), 1);
for v = 1:size(L, 1)
%For column condition
if L(v, 3)~= 3
%Mark line for deletion afterwards
deleterow(v) = true;
end
end
L(deleterow,:) = [];
L=L(:,1:2);
L=sortrows(L,1);
%Brochothrix thermosphacta
Br=data;
deleterow = false(size(Br, 1), 1);
for q = 1:size(Br, 1)
%For column condition
if Br(q, 3)~= 3
%Mark line for deletion afterwards
deleterow(q) = true;
end
end
Br(deleterow,:) = [];
Br=Br(:,1:2);
Br=sortrows(Br,1);
%The data is plotted (growth rate against temperature)
figure
plot(S(:,1), S(:, 2), Ba(:,1), Ba(:, 2), L(:,1), L(:, 2), Br(:,1), Br(:, 2))
xlim([10 60])
ylim([0; Inf])
xlabel('Temperature')
ylabel('Growth rate')
title('Growth rate as a function of temperature')
legend('Salmonella enterica','Bacillus cereus','Listeria','Brochothrix thermosphacta')
Can anyone help me fix it so when I have a matrix without eg 2 in the third column, it will still plot correctly?
I do know how to filter it correctly, and apply that filtering to 'data', so the only problem is the error codes occurring when plotting.
The errors are;
Warning: Ignoring extra legend entries.
> In legend>set_children_and_strings (line 643)
In legend>make_legend (line 328)
In legend (line 254)
In dataPlot (line 82)
In Hovedscript (line 153)
When running this function from a main script with the matrix sorted by growth rate (second column) and filtering for only third row values 1, 3 and 4 to be analyzed. The filtering is done through another function, done in advance, and the new 'data' looks like this.
59.2390 0.0584 1.0000
58.7110 0.1558 4.0000
14.7690 0.1796 4.0000
56.1370 0.2052 1.0000
17.3260 0.2304 4.0000
52.9660 0.2604 4.0000
10.9310 0.2747 3.0000
41.5570 0.3898 4.0000
51.9480 0.3932 1.0000
54.2200 0.4058 3.0000
15.8520 0.4592 3.0000
50.0190 0.4754 1.0000
51.7180 0.4927 3.0000
51.3290 0.5050 3.0000
50.7340 0.5237 3.0000
13.5340 0.5742 1.0000
45.7840 0.6254 1.0000
22.3110 0.6536 3.0000
46.0430 0.6611 3.0000
45.6900 0.6684 3.0000
44.7400 0.6884 3.0000
43.7390 0.7043 3.0000
26.2430 0.7305 3.0000
42.3400 0.7371 1.0000
26.3020 0.7379 3.0000
40.4810 0.7621 3.0000
29.5010 0.7789 3.0000
38.7370 0.7834 3.0000
31.9250 0.7948 3.0000
31.8910 0.7954 3.0000
34.8950 0.8050 3.0000
32.8210 0.8072 3.0000
39.1220 0.8102 1.0000
37.1830 0.8513 1.0000
24.2970 0.8615 1.0000
25.3870 0.8774 1.0000
Again, the bar plot works just fine, but does show all 4 bacteria even when only 3 of them are used, and the problem is in the line plot, with one line not showing in the plot.
Thank you for your time
A solution is to replace the following lines
plot(S(:,1), S(:, 2), Ba(:,1), Ba(:, 2), L(:,1), L(:, 2), Br(:,1), Br(:, 2))
legend('Salmonella enterica','Bacillus cereus','Listeria','Brochothrix thermosphacta')
by
hold on
plot(S(:,1), S(:, 2), 'DisplayName', 'Salmonella enterica');
plot(Ba(:,1), Ba(:, 2), 'DisplayName', 'Bacillus cereus');
plot(L(:,1), L(:, 2), 'DisplayName', 'Listeria');
plot(Br(:,1), Br(:, 2), 'DisplayName', 'Brochothrix thermosphacta');
legend SHOW;
In this way, the legend entries are explitely assigned to a specific plot, which works even if some plots are empty.
Copy and Paste mistake
L == Br in the provided code due to a copy and paste mistake. You should change if Br(q, 3)~= 3 into if Br(q, 3)~= 4.
Result
If I use your second input data (without 2 in the third column), I get the following (without any error message):

implementing "not equal to " loop in matlab

i have a simple problem i am quite new to matlab so i am having problem in implementing it i have two 64x2 matrices u and h.i have to check if a single row in u is not equal to all of the rows in h.then the row which is not equal should be saved in a separate matrix meanwhile i have written this code but what it does is that r(i,:) get all the values of u(i,:) when this code runs, what i want is that only those values of u(i,:) should be stored in r which are not similar to any row in h matrix.
h=[];
for j=1:8
for i=1:8
h=[h; i j];
end
end
u=[5.3,1.4;6,8;2,3;3,5.5;2.6,8;3.7,2;4,2;5,3;1.9,8;5.4,4;3.2,3;2,2;2,4;2,3;8,2.2;8,4;7.3,1.5;6.2,5.1;2.4,1.5;3,5;2,7.1;1.8,2.7;3,4;6,5;6,1;5,4;4,6;3.5,2;5,7;7.2,8;7,7;5,5;6,3;6,6;1,2;5,8;3,5;1,5;2,2;2,1;6,3;4,7;6,8;3,6;1,6;5,2;3,5;8,7;8,4;4,8;1,1;6,3;7,5;8,1;1,6;4,5;5,5;6,7;6,7;6,7;6,3;3,4;5,7;1,1]
for i=1
for j=1:64
if u(i,:)==h(j,:)
c=1
else
c=0
if c==0
r(i,:)=u(i,:)
end
end
end
end
can anyone help me please
You can do it in one line with ismember:
r = u(~ismember(u,h,'rows'),:);
With your example data, the result is
>> r
r =
5.3000 1.4000
3.0000 5.5000
2.6000 8.0000
3.7000 2.0000
1.9000 8.0000
5.4000 4.0000
3.2000 3.0000
8.0000 2.2000
7.3000 1.5000
6.2000 5.1000
2.4000 1.5000
2.0000 7.1000
1.8000 2.7000
3.5000 2.0000
7.2000 8.0000
use setdiff with 'rows' option to compute r. Please avoid unnecessary loops. pre-allocate when possible.
% construct h without loop
[h{1} h{2}]=ndgrid(1:8,1:8);
h=[h{1}(:) h{2}(:)];
% get r using setdiff
r = setdiff( u, h, 'rows')
Results with
r =
1.8000 2.7000
1.9000 8.0000
2.0000 7.1000
2.4000 1.5000
2.6000 8.0000
3.0000 5.5000
3.2000 3.0000
3.5000 2.0000
3.7000 2.0000
5.3000 1.4000
5.4000 4.0000
6.2000 5.1000
7.2000 8.0000
7.3000 1.5000
8.0000 2.2000
Solution of you question in NlogN complexity (N=64):
N=size(h,1);
[husorted,origin_husorted,destination_hu]=unique([h;u],'rows','first');
iduplicates=destination_hu(N+1:end)<=destination_hu(N),:);
r=u;
r(iduplicates,:)=0;
destination_uh is the only output of unique that is useful; It verifies [h;u]=husorted(destination_uh,:)]. 'first' ensures that if line i of u is equal line j of h, then destination_uh(i+N) is equal to destination_uh(j).
Solution for your particular h, with complexity N:
r=u;
r(all(u==round(u)&u>=1&u<=8,2),:)=0;

How do I append elements to a matrix using a for loop?

I have following data matrix, I want to iterate over this matrix and look at a value in the last column based on a given row and add that row - last element of that row to a new matrix.
5.1000 3.3000 1.7000 0.5000 1.0000
6.8000 3.2000 5.9000 2.3000 3.0000
5.0000 2.3000 3.3000 1.0000 2.0000
7.4000 2.8000 6.1000 1.9000 3.0000
6.5000 3.2000 5.1000 2.0000 3.0000
4.8000 3.4000 1.9000 0.2000 1.0000
4.9000 3.0000 1.4000 0.2000 1.0000
5.1000 3.8000 1.5000 0.3000 1.0000
5.1000 3.4000 1.5000 0.2000 1.0000
5.5000 2.6000 4.4000 1.2000 2.0000
This is the code that I have
M1 = [];
M2 = [];
M3 = [];
for i=1:length(currentCell)
if currentCell(1,5) == 1.00
m3Data = currentCell(1:1,1:4);
%how can I add m3Data to M1
end
end
Let your original matrix be M, then this
M1 = M(find(M(:,5)==1),1:4)
puts all the rows ending with a 1 into M1, excluding the final column. Is that what you want ?
You could do it with a for loop if you want, but I don't see any need.

Matlab: Randomize and Split

I have following data matrix in Matlab, I am trying to actually split this into multiple segments by passing a variable to a matlab function. But before splitting I would like to shuffle the matrix. The size of my matrix is 150X4
s.data
5.1000 3.5000 1.4000 0.2000
4.9000 3.0000 1.4000 0.2000
4.7000 3.2000 1.3000 0.2000
4.6000 3.1000 1.5000 0.2000
5.0000 3.6000 1.4000 0.2000
..
s =
data: [150x4 double]
labels: [150x1 double]
Coming from R environment I find MatLab is very strange. Initially I thought the columns in matrix has a relationshop like in a R dataframe but thats wrong in my assumption.
or you can do:
perm=randperm(numel(data)); % generate a random permutation
data = reshape(data(perm),size(data)); % apply it to data
new_data=data(randsample(1:length(data),length(data)),:)
Complementing the shuffle answers, in order to split your data into matrices of 15x2 each, you can use mat2cell:
data = rand(150,4); %# generates a random 150x4 matrix
rowdiv = repmat(15,1,10); %# size of each chunk in rows. Must sum to 150
coldiv = repmat(2,1,2); %# size of each chunk in cols. Must sum to 4
datacell = mat2cell(data, rowdiv, coldiv)
It will return a cell with 20 matrices, which are accessed by datacell{x,y}:
datacell =
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
[15x2 double] [15x2 double]
B = repmat(A,M,N) creates a large matrix B consisting of an M-by-N tiling of copies of A. We are using it here to generate an exact division of the rows and columns, repeating element 15 ten times and 2 twice, respectively. But, you don't need to do an exact division. You can set chunks with different sizes. Row with different size:
rowdiv =
15 15 15 15 15 15 15 15 16 14
Will return:
datacell =
[15x4 double]
[15x4 double]
[15x4 double]
[15x4 double]
[15x4 double]
[15x4 double]
[15x4 double]
[15x4 double]
[16x4 double]
[14x4 double]