Suppose I have a series of strings such as:
a = '101010101010'
b = '010101'
c = '000101010'
is there a way in Matlab to concatenate them and produce the binary number 101010101010010101000101010?
Use the concatenation operator [ ], with horizontal concatenation , (vertical concatenation ; will fail here unless you reshape() into column vectors):
[a,b,c]
However, I suggest storing your variables in a cell array:
s = {'101010101010','010101', '000101010'};
[s{:}]
or
cat(2,s{:})
To concatenate strings, you could say:
out = [a b c];
Alternatively:
out = strcat(a,b,c);
Yet another way:
out = sprintf('%s', a,b,c);
I think that this should work:
res = [a,b,c]
or alternatively call
res = strcat(a,b,c)
or, yet
res = cat(2,a,b,c)
Related
I have a working piece of code in MATLAB
empty_string = "";
bag = repmat(empty_string, 4, 1);
bag(2) = "second row";
bag(3) = "third";
However, I want to convert this to octave as MATLAB is a licensed version and everyone can't get access to it.
empty_string = blanks(1);
bag = repmat(empty_string, 4, 1);
bag(2) = "second row";
bag(3) = "third";
This gives error: =: nonconformant arguments (op1 is 1x1, op2 is 1x10)
I want each row of matrix 'bag' to be filled with uneven number of characters, please suggest how this can be done in octave. Thanks.
Since MATLAB strings have not been implemented in Octave, you will need to use a cell array of char arrays. Fortunately, this is pretty simple. Just change the first two lines in your code sample to create a cell array of the proper size:
bag = cell(4,1);
bag(2) = "second row";
bag(3) = "third";
The result is:
bag =
{
[1,1] = [](0x0)
[2,1] = second row
[3,1] = third
[4,1] = [](0x0)
}
The one annoyance is that in order to reference your char arrays in the cell array, you need to use curly braces instead of parentheses:
>> second = bag{2}
second = second row
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:
Suppose I have:
a=[2;3];
b=[4;5];
c=[1;1];
How can I print the result as
s=
2,4,1
3,5,1
So far I have tried with:
a=[2;3];
b=[4;5];
c=[1;1];
s=sprintf('%d,%d,%d\n',a,b,c)
but I am not getting the desirable result.
At first you can merge them into a matrix and then do the following:
res = [a b c];
str = sprintf('%d,%d,%d\n',res.');
you can do
s = sprintf('%d,%d,%d\n', [a,b,c]')
which gives
s = 2,4,1
3,5,1
Let's say that I have 2 3D-Matrix:
A = rand(10,4,100);
B = rand(10,4,100);
L = gt(A,B);
Now I want substitute all elements of B with elements of A only where L==1but this doesn't work:
B(L==1,:,:) = A(L==1,:,:);
Any suggestion?
Our even shorter whithout find
B(L) = A(L);
Sounds like a job for the find() function.
p = find(L);
B(p) = A(p);
EDIT: Just realized you don't need the find() function. Just use logical indexing like this:
B(L==1) = A(L==1);
I have to write a function to replace the characters of a string with those letters.
A=U
T=A
G=C
C=G
Example:
Input: 'ATAGTACCGGTTA'
Therefore, the output should be:
'UAUCAUGGCCAAU'
I can replace only one character. However, I have no how to do several. I could replace several if '"G=C and C=G" this condition was not there.
I use:
in='ATAGTACCGGTTA'
check=in=='A'
in(check)='U'
ans='UTUGTUCCGGTTU'
if I keep doing this at some point G will be replaced by C then then all the C will be replaced by G. How can I stop this?? Any help will be appreciated.
Just for fun, here's probably the absolute simplest way, via indexing:
key = 'UGCA';
[~, ~, idx] = unique(in);
out = key(idx'); % transpose idx since unique() returns a column vector
I do love indexing :D
Edit: As rightly pointed out, this is very optimised for the question as stated. Since [a, ~, idx] = unique(in); returns a and idx such that a(idx) == in, and by default a is sorted, we can just assume that a == 'ACGT' and pre-construct key to be the appropriate translation of indices into a.
If some characters from the known alphabet never appear in the input string, or if other unknown characters appear, then the indices don't match and the assumption breaks. In that case, we have to calculate the appropriate key explicitly - filling in the step that was optimised out above:
alph = 'ACGT';
trans = 'UGCA';
[key, ~, idx] = unique(in);
[~, alphidx, keyidx] = intersect(alph, key); % find which elements of alph
% appear at which points in key
key(keyidx) = trans(alphidx); % translate the elements of key that we can
out = key(idx');
The simplest way would be to use an intermediary letter. For instance:
in='ATAGTACCGGTTA'
in(in == 'A')='U'
in(in == 'T')='A'
in(in == 'C')='X'
in(in == 'G')='C'
in(in == 'X')='G'
This way you keep the 'C' and 'G' characters separate.
EDIT:
As others have mentioned, there are a few things other things you could do to improve this approach (though personally I think Notlikethat's way is cleanest). For instance, if you use a second variable, you don't have to worry about keeping 'C' and 'G' separate:
in='ATAGTACCGGTTA'
out=in;
out(in == 'A')='U';
out(in == 'T')='A';
out(in == 'C')='G';
out(in == 'G')='C';
Alternatively, you could make your indices first, then index after:
in='ATAGTACCGGTTA'
inA=in=='A';
inT=in=='T';
inC=in=='C';
inG=in=='G';
in(inA)='U';
in(inT)='A';
in(inC)='G';
in(inG)='C';
Finally, my personal favourite for sheer idiocy:
out=char(in+floor((68-in).*(in<70)*7/4)*4-round(ceil((in-67)/4)*3.7));
(Seriously, that last one works)
You can perform multiple character translation with bsxfun.
Inputs:
in = 'ATAGTACCGGTTA';
pat = ['A','T','G','C'];
subst = ['U','A','C','G'];
out0 ='UAUCAUGGCCAAU';
Translate all characters simultaneously:
>> ii = (1:numel(pat))*bsxfun(#eq,in,pat.'); %' instead of repmat and .*
>> out = subst(ii)
out =
UAUCAUGGCCAAU
>> isequal(out,out0)
ans =
1
Say you only want to translate a subset of the characters, leaving part of the sequence intact, it is easily solved with logical indexing and a few extra lines:
% Leave the Gs and Cs in place
pat = ['A','T'];
subst = ['U','A'];
ii = (1:numel(pat))*bsxfun(#eq,in,pat.'); %' same
out = char(zeros(1,numel(in)));
nz = ii>0;
out(nz) = subst(ii(nz));
out(~nz) = in(~nz)
out =
UAUGAUCCGGAAU
The original Gs and Cs are unchanged; A became U, and T became A (T is gone).
I would suggest to use containter.Map:
m=containers.Map({'A','T','G','C'},{'U','A','C','G'})
mapfkt=#(input)(cell2mat(m.values(num2cell(input))))
Usage:
mapfkt('ATAGTACCGGTTA')
Here is another method that should be fairly efficient, general, and in the line of thought of your original attempt:
%Suppose this is your input
myString = 'abcdeabcde';
fromSting = 'ace';
toString = 'xyz';
%Then it just takes this:
[idx fromLocation] = ismember(myString,fromSting)
myString(idx)=toString(fromLocation(idx))
If you know that all letters need to be replaced, the last line can be slightly simplified as you wont need to use idx.