I have a series of arrays ("A", "B", etc.). My program prompts users to select 2 different arrays and it then returns the values common to both.
I want to be able to run this loop multiple times and save the output (ComVal) from each iteration. I've tried using cells but that hasn't been working; I don't know if it's because of the way I've written my code.
for k=0;
prompt_a='Select an array: ';
str_a=input(prompt_a);
prompt_b='Select second array: ';
str_b=input(prompt_b);
ComVal=intersect(str_a,str_b);
end
Right now if I alter k so I can run it several times, it only saves the final iteration.
You can save the results into a cell very similar to saving it into a standard array.
numIterations = 5;
comVals = cell(1,numIterations)
for k = 1:numIterations
prompt_a='Select an array: ';
str_a=input(prompt_a);
prompt_b='Select second array: ';
str_b=input(prompt_b);
comVals{k} = intersect(str_a,str_b);
end
Related
I am a newbie. I have problem.
I have 20 (1x100) different named vectors. I want to combine these vectors to create a 20x100 matrix with a for loop.
There are the examples of vectors.
namelist=["First","B","New"]
First = [1:100]
B = [1:2:200]
New = [4:4:400]
for i = 1: length(namelist)
new_database(i,1:end) = namelist{i}
end
But, when I want to try this I saw "The end operator must be used within an array index expression." error.
I know I can do same thing with this:
"new_database= [First;B;New]"
but i want to do this with a for loop.
Would you help me how can fix this error? or Would you explain me how can do this?
Your problem is with this line:
new_database(i,1:end) = namelist{i}
the curly braces are used with cells, exclusively and there is no need to use range indexing as you do (i, 1:end)
Generally, it is better practice to assign character arrays or strings to cells.
One question, what are you doing with the 'First', 'New' and 'B' ranges arrays?
Something like:
namelist=["First","B","New"]
First = [1:100];
B = [1:2:200];
New = [4:4:400];
new_database = cell(1, length(namelist));
for i = 1: length(namelist) % or length(new_database)
new_database{i} = namelist(i)
end
which generates this output:
EDIT: My apologies, now I see what you are trying to accomplish. You are building a database from a series of arrays, correct?
Following my previous response, you must consider some points:
1 Your new_database should be square. Regardless of the dimensions of the arrays you are passing to it, if you form a cell from them, you will invariably have empty cells if no data is passed to those rows or columns
2 In some cases, you don't need to use for-loops, where simple indexing might suffice your case problem. Consider the following example using cellstr:
titles = ["Position", "Fruits", "Mythical creatures"]
A = ["One", "Two", "Three"];
B = ["Apple", "Banana", "Durian"];
C = ["Dragon", "Cat", "Hamster"];
db = cell(4, 3);
db(1,:) = cellstr(titles)
db(2:end,1) = cellstr(A)
db(2:end,2) = cellstr(B)
db(2:end,3) = cellstr(C)
which generates this output:
I have an array like t. It contains the numbers and I would like to add to each number the previous ones. For example: t=[0,2,3,5] and I would like to get tnew=[0,2,5,10]. I tried out this code but it is wrong for sure. (There are 5292 values)
for i=0:5292
t(i)=t(i)+t(i+1)
end
For some array t = [0,2,3,5];, you can just do tnew = cumsum(t).
If you really want to do this in a loop, you need to start from the 2nd index, and keep adding to the value from the previous index
t = [0,2,3,5];
tnew = t;
for ii = 2:numel(t)
tnew(ii) = t(ii) + tnew(ii-1);
end
I have a matrix 10x500 and I want to discard every row which contains in the first 100 elements a value above 6. First I am trying to make an array with all the indexes of the row to discard. Here my code
idx_discard_trials = [];
for i = 1:size(data_matrix,1)
if any(data_matrix(i,1:100)>6)
idx_discard_trials = i;
end
end
However, at the end of the loop I get just the last index, not a list. Does anybody know how to append elements to an array using a for loop?
It's because you keep rewriting a single value, you need to append the values through idx_discard_trials(end+1) = i, for example.
You don't need a loop for this however, try the following:
data_matrix(any(data_matrix(:,1:100) > 6, 2),:) = []
I have a loop which runs 100 times. In each iteration there is a string, double and a table assigned, and in the next iteration new values are assigned for them. What I want to do is to accumulate these values and after the loop finishes save the total result as result.mat using the matlab save function. I've tried putting them in cell-array but its not working so far, so if anyone could please advise how this can be done.
This is what I did:
results_cell=(100,3);
.
.
.
results_cell(i,1)=stringA;
results_cell(i,2)=TableA;
results_cell(i,3)=DoubleA;
But it gives this error Coversion to Cell from Table is not possible. So I've tried converting TableA to array of Doubles using table2array but I still get this Coversion to Cell from Double is not possible
I think using a structure would be a good way to store your data, since they are of different types and you can assign it meaningful field names for easy reference.
For example, let's call the structure Results. You can initialize it like so.
Results = struct('StringData',[],'TableData',[],'DoubleData',[])
Since you know its dimensions, you can even do this:
N = 100;
Results(N).StringData = [];
Results(N).TableData = [];
Results(N).DoubleData = [];
This automatically create a 1xN structure with 3 fields.
Then in your loop you can assign each field with its associated data like so:
for k = 1:N
Results(k).StringData = String(k);
Results(k).TableData = Table(k);
Results(k).DoubleData = Double(k);
end
where String(k), Table(k) and Double(k) are just generic names for your actual data.
When you're done with the loop you can access any type of data using a single index and the right field name.
In order to save a .mat file, use something like this:
save SomeFileName.mat Results
Which you can load into the workspace as you would with any .mat file:
Eg:
S = load('SomeFileName.mat')
R = S.Results
Hope that helps!
what I need to do for this code is import a giant (302x11) excel doc, and then ask the user for an input. Then, I need to iterate through each element in the 5th column of the excel array, and if that element matches the user input, save the entire row to a new array. After going through all 302 rows, I need to display the new array.
So far, I have this:
Vin = input('Vin: ');
filename='MagneticCore.xlsx';
sheet=2;
xlRange='B2:L305';
[ndata, text, alldata] = xlsread(filename,sheet,xlRange,'basic');
After this, I'm not sure how to iterate through the alldata array.
alldata is a cell, to select the fifth column you can use alldata{:,5}. Searching in Cells is done this way without iterating
Try it on your own, if you get stuck update your question with code and error message
Daniel R is right, you can do this without iterating through the cell array. Here's how you could iterate through the array if you needed to:
[ndata, text, alldata] = xlsread('Book1.xlsx');
target = 12;
newArray = {};
for r = 1:size(alldata, 1)
% get the element in the fifth column of the current row
e = raw{r,5};
if e == target
% add to newArray
newArray{end + 1} = alldata(r,:);
end
end
% display newArray
for r = 1:size(newArray, 1)
disp(newArray{r})
end