I have a cell array, c, filled with hexadecimal data and when I view the cell contents by typing c at the matlab prompt, it shows me contents enclosed between ticks, i.e., '0x0009'. But, one element is enclosed in brackets and looks like [650345]. How can I convert the [ ] data to ' ' data? When I do iscellstr on this particular element, matlab returns 0. iscellstr returns 1 for all other elements of c.
I'm reading this data into matlab from excel and I fear that excel 'helped' me by converting one hex value to scientific notation. I can't, as far as I've found, change what excel did. I think the true value is lost and unrecoverable. But I need to convert this one outstanding value, even if incorrect, to be like the other cell values so that I can carry on with my processing. Any suggestions?
If you know the index of wrong value and it's true value, you just do:
c(idx) = {'0x0009'};
I think this does what you want:
ind = cellfun(#isnumeric, c); %// find numeric cells
c(ind) = cellfun(#(s) ['0x' dec2hex(s)], c(ind), 'uniformout', 0); %// convert to
%// hex string and prepend '0x'
Example: input
c = {'0x0009', 650345};
produces the output
c =
'0x0009' '0x9EC69'
Related
I have a cell array. Some of the elements in this cell array contains zeros as the first character and the whole element is only numbers (double) as well. When exporting these to Excel (which I prefer), the zeros are deleted and converting it to a number.
Let's take an example to illustrate my problem. I have a cell array with 10 elements:
NodeID = {'0000006';
'0000011';
'000011R';
'000016R';
'000021R';
'B276_2';
'EB 7.55';
'EB2521';
'EllebaekOPlB1';
'EllebaekOplB10'};
The first two elements contains zeros until the number 6 and 11, respectively. Unlike the third element and so forth, where letters are involved. So when exporting NodeID to Excel, it returns this in a column (I use writetable command by the way):
6
11
000011R
000016R
000021R
B276_2
EB 7.55'
EB2521
EllebaekOPlB1
EllebaekOplB10
Notice the removal of zeros for the first two elements. Now I know that in Excel, it will keep all the content with the addition of a quote symbol ' in front of the cell, eg. '0000006 for the first element.
I have searched in many places to find a solution to this. But is there a good way to avoid this from happening? Either by somehow adding an extra ยด or some other magical trick which I have not seen?
Thank you in advance!
One alternative (if your values are in a cell, as you say they are):
filename = 'NodeID.xlsx';
NodeID2 = cellfun(#(C) ['''',C], NodeID,'UniformOutput', false)
xlswrite(filename, NodeID2)
This gives you:
NodeID2 =
''0000006'
''0000011'
''000011R'
''000016R'
''000021R'
''B276_2'
''EB 7.55'
''EB2521'
''EllebaekOPlB1'
''EllebaekOplB10'
And an Excel file looking like this:
The cellfun line is equivalent to:
for ii = 1:numel(NodeID)
NodeID2{ii,1} = ['''', NodeID{ii}];
end
The part ['''', NodeID{ii}] inserts a single quotation mark in front for the string. Relevant answer.
I would like to covert three <1xN cell> (A, B and C) into a single Nx3 matrix. Could someone help me with this?
C={{1xN}; {1xN}; {1xN}};
where each N is a number in single quotes, e.g.
C = {{'123123' ,'12324', ....N times}; {'123123', '12324', ....N times}; {'123123', '12324' ,....N times}}
Since a couple of them mentioned about the ridiculous input, this is the reason for having it in the above form.
The three nested array of cells are the results of a regexp where my string and expression are both strings. Therefore I have the output of regexp as three cell arrays of row vectors.
For e.g.
node_ids=regexp(nodes,'(?<=node id=")\d*','match');
I can use cat function and then use a str2double for all three cell arrays and finally form a matrix by cell2mat.
For e.g.
node_ids=cat(1,node_ids{:});node_ids=str2double(node_ids);
But this takes more time and has more LOC.
My question is can it be done with fewer lines of code?
I tried using the cat function but keep getting this error:
Cannot support cell arrays containing cell arrays or objects.
Your input data is pretty bad.... why are you using a nested array of cells where each element is a string?
In any case, assuming C is your original input data, do this:
C = {{'123123' '12324'}; {'123123' '12324'}; {'123123' '12324'}};
out = cellfun(#(x) cellfun(#str2num, x, 'uni', 0), C, 'uni', 0);
out = cell2mat(cellfun(#cell2mat, out, 'uni', 0));
First line is some dummy data. Next line first goes through every nested cell element over your cell array and converts the strings into numbers. However, these are still in cell arrays. As such, the next line converts each cell array in the nested cell into a matrix, then we merge all of the cells together into one final matrix.
We get:
>> out
out =
123123 12324
123123 12324
123123 12324
I am trying to create a string array which will be fed with string values read from a text file this way:
labels = textread(file_name, '%s');
Basically, for each string in each line of the text file file_name I want to put this string in 10 positions of a final string array, which will be later saved in another text file.
What I do in my code is, for each string in file_name I put this string in 10 positions of a temporary cell array and then concatenate this array with a final array this way:
final_vector='';
for i=1:size(labels)
temp_vector=cell(1,10);
temp_vector{1:10}=labels{i};
final_vector=horzcat(final_vector,temp_vector);
end
But when I run the code the following error appears:
The right hand side of this assignment has too few values to satisfy the left hand side.
Error in my_example_code (line 16)
temp_vector{1:10}=labels{i};
I am too rookie in cell strings in matlab and I don't really know what is happening. Do you know what is happening or even have a better solution to my problem?
Use deal and put the left hand side in square brackets:
labels{1} = 'Hello World!'
temp_vector = cell(10,1)
[temp_vector{1:10}] = deal(labels{1});
This works because deal can distribute one value to multiple outputs [a,b,c,...]. temp_vector{1:10} alone creates a comma-separated list and putting them into [] creates the output array [temp_vector{1}, temp_vector{2}, ...] which can then be populated by deal.
It is happening because you want to distribute one value to 10 cells - but Matlab is expecting that you like to assign 10 values to 10 cells. So an alternative approach, maybe more logic, but slower, would be:
n = 10;
temp_vector(1:n) = repmat(labels(1),n,1);
I also found another solution
final_vector='';
for i=1:size(labels)
temp_vector=cell(1,10);
temp_vector(:,1:10)=cellstr(labels{i});
final_vector=horzcat(final_vector,temp_vector);
end
I have some which converts a cell array of strings into a cell array of characters.
Note. For a number of reasons, both the input (C) and the output (C_itemised) must be cell arrays.
The cell array of strings (C) is as follows:
>> C(1:10)
ans =
't1416933446'
''
't1416933446'
''
't1416933446'
''
't1416933446'
''
't1416933446'
''
I have only shown a portion of the array here. In reality it is ~28,000 rows in length.
I have some code which does this, although it is very inefficient. The cellstr function takes up 72% of the code's time, as it is currently called thousands of times. The code is as follows:
C_itemised=cell(length(C),500);
for i=3:length(C)
temp=char(C{i});
for j=1:length(temp)
C(i-2,j)=cellstr(temp(j));
end
end
I have a feeling that some minor modifications could take out the inner loop, thus cutting down the overall running time substantially. I have tried a number of ways to do this, but I think I keep getting confused about whether to use {} or (), and haven't been able to find anything online that can help me. Can anyone see a way to make the code more efficient?
Please also note that this function is used in conjunction with other functions, and does work, although it is running slower than would be ideal. Therefore, I do not wish to change the format of C_itemised.
EDIT:
(A sample of) the output of my current function is:
C_itemised(1,1:12)
ans =
Columns 1 through 12
't' '1' '4' '1' '6' '9' '3' '3' '4' '4' '6' []
One thing I can suggest is to use the undocumented function sprintfc. This function is hidden from normal use in MATLAB, but it is used internally with a variety of other functions. Mainly, if you tried doing help sprintfc, it'll say that there's no function found! It's cool to sniff around the source sometimes!
How sprintfc works is that you provide it a formatting string, much like printf, and the data you want printed. It will take each individual element in the data and place them into individual cell arrays. As an example, supposing I had a string D = 'abcdefg';, if we did:
out = sprintfc('%c', D);
We get:
>> celldisp(out)
out{1} =
a
out{2} =
b
out{3} =
c
out{4} =
d
out{5} =
e
out{6} =
f
out{7} =
g
As such, it takes each element in your string and places them as individual characters serving as individual elements in a new cell array. The %c formatting string means that we want to print a single character per element. Check out the link to Undocumented MATLAB that I posted above if you want to learn more!
Therefore, try simplifying your loop to this:
C_itemised=cell(length(C));
for i=1:length(C)
C_itemised{i} = sprintfc('%c', C{i});
end
C_itemised will be a cell array, where each element C_itemised{i} is another cell array, with each element in this cell array being a single character that is composed of the string C{i}.
Minor Note
You said you were confused about {} and () in MATLAB for cells. {} is used to access individual elements inside the cell. So doing C{1} for example will grab whatever is stored in the first element of the cell array. () is used to slice and index into the cells. For example, if you wanted to make another cell array that is a subset of the current one, you would do something like C(1:3). This will create a three element cell array which is composed of the first three cells in C.
This is my first time posting so i hope you can help me. I am trying to write a function in matlab.
I have laded data from a file into a cell array. First column contains statements and the second contains T for true og F for false. I now want to split this array into a cell array with the statements and a logical vector with 1 for True and -1 for false.
I use the fgetl within a loop to read all the lines into the cellarray
Try to write it a bit more neatly next time, and consider including a small example.
Here is what you seem to be looking for:
Suppose you have a matrix M and want to split that into M_true and M_false
M = {1,'T';
22,'F';
333,'T'}
idx_T=strcmp(M(:,2),'T')
M_true = M(idx_T,1)
M_false = M(~idx_T,1)