I want to make a Matlab function that takes two matrices A and B (of the same size) and combines them in a certain way to give an output that can be used in Latex - table.
I want the first row of the output matrix to consist of the first row of matrix A, with ampersands (&) in between them, and that ends with an double backslash.
The second row should be the first row of B with parentheses around them, and ampersands in between. And so on for the rest of A and B.
If I let A=rand(1,2), I could do this by using [num2str(A(1)), ' & ', num2str(A(2)),' \\'] and so on.
But I want to be able to make a function that does this for any size of the matrix A. I guess I have to make cell structures in some way. But how?
This could be one approach -
%// First off, make the "mixed" matrix of A and B
AB = zeros(size(A,1)*2,size(A,2));
AB(1:2:end) = A;
AB(2:2:end) = B;
%// Convert all numbers of AB to characters with ampersands separating them
AB_amp_backslash = num2str(AB,'%1d & ');
%// Remove the ending ampersands
AB_amp_backslash(:,end-1:end) = [];
%// Append the string ` \\` and make a cell array for the final output
ABcat_char = strcat(AB_amp_backslash,' \\');
ABcat_cell = cellstr(ABcat_char)
Sample run -
A =
183 163 116 50
161 77 107 91
150 124 56 46
B =
161 108 198 4
198 18 14 137
6 161 188 157
ABcat_cell =
'183 & 163 & 116 & 50 \\'
'161 & 108 & 198 & 4 \\'
'161 & 77 & 107 & 91 \\'
'198 & 18 & 14 & 137 \\'
'150 & 124 & 56 & 46 \\'
' 6 & 161 & 188 & 157 \\'
You can use sprintf, it will repeat the format spec as many times as required until all input variables are processed:
%combine both to one matrix
C=nan(size(A).*[2,1]);
C(1:2:end)=A;
C(2:2:end)=B;
%print
sprintf('%f & %f \\\\\n',C.')
The transpose (.') is required to fix the ordering.
Related
In MATLAB (R2015a), I have two large matrices that can be simplified as:
A = [ 24 10 830; 24 15 830; 150 17 945; 231 40 1130; 231 45 1130]
(note that in A, column 3 is the time for the event cataloged in column 1) and
B = [24 13; 150 29; 231 43]
How can I match and copy the time-data from column 3 in matrix A, to a matching and filtered event column in matrix B?
For example, I want the value 24 from first column in B to be matched with value 24 from first column in A, and then copy the corresponding time-data in A's third column (for 24 it's 830, for 150 it's 945 etc.) into B. This should result into our new B with the time-data from A:
B = [24 13 830; 150 29 945; 231 43 1130]
I relatively new to MATLAB so any help is much appreciated!
First find the location of the elements in the first row of B in the first row of A using the ismember function. And then use those locations to construct the new matrix.
[~,Locb] = ismember(B(:,1),A(:,1));
Bnew = [B A(Locb,3)]
Bnew =
24 13 830
150 29 945
231 43 1130
This is a fast way that comes to my mind. There might be some singularities that needed to be checked more thoroughly.
I'm having an array and when I apply find(im), I get indices for non zero elements. But, I want indices for all elements of array irrespective whether it is zero or non zero.
Here is my array:
im =[94 122 99 101 111 101;
99 92 103 87 107 116;
93 109 113 84 86 106;
5 17 6 54 56 53;
13 11 5 56 44 50;
0 10 5 49 42 51];
when I apply find(im): I get indices: 35(Since the array contain 0 in it). But I need to get 36.
How do i do it?
Since you want the linear indices of all elements in the array, and you know the number of elements in the array, their indices will be:
im = magic(5);
indices = 1:numel(im)
I.e. if you were to loop the array you would be looping all of the elements.
Is default '\n' Matlab line terminator can be changed? Can I use ',' instead of '\n'? Because the serial port that will be reading it is programmed to terminate when ',' is read.Is it possible?
Any answers are highly appreciated! Thanks in advance!
use eg:
ser = serial('COM1'); % establish connection between Matlab and COM1
set(ser, 'Terminator', 'CR'); % set communication string to end on ASCII 13
and replace 'CR' with ','
See
http://www.swarthmore.edu/NatSci/ceverba1/Class/e5/E5MatlabExamples.html
http://www.mathworks.co.uk/help/matlab/matlab_external/terminator.html
A simple string in matlab is not terminated by \n or \0 since it is a simple array of chars, as seen here:
>> a = string('Hello World')
Warning: string is obsolete and will be discontinued.
Use char instead.
a =
Hello World
>> double(a)
ans =
72 101 108 108 111 32 87 111 114 108 100
to add a \0 to the end simply use:
>> a(end+1)=0;
>> a
a =
Hello World
>> double(a) %the zero is there, but not printable as seen here
ans =
72 101 108 108 111 32 87 111 114 108 100 0
I have to make a matlab program, which should create a QR Code.
My problem is the Reed Solomon error correction
The user enters the word he wants. [...] I got a string of numbers I should be gone in a polynomial generator (Reed Solomon) (I found some sites that do this very well: http://www.pclviewer.com/rs2/calculator.html)
I would like it to happen: for example I input: 32 91 11 120 209 114 220 77 67 64 236 17 236
[Reed Solomon generator polynomial]
and I want to find out: 168 72 22 82 217 54 156 0 46 15 180 122 16
I found the functions rsenc comm.rsencoder gf ... But it is impossible to understand the operation of these functions. Functions are detailed: http://www.mathworks.fr/fr/help/comm...n.html#fp12225
I tried a code of this type :
n = 255; k = 13; % Codeword length and message length
m = 8; % Number of bits in each symbol
msg = [32 91 11 120 209 114 220 77 67 64 236 17 236]; % Message is a Galois array.
obj = comm.RSEncoder(n, k);
c1 = step(obj, msg(1,:)');
c = [c1].';
He produced a string of 255 while I want 13 output.
Thank you for your help.
I think that you are committing a mistake.
'n' is the length of final message with parity code.
'k' is the lenght of message (number of symbols)
I guess that this will help you:
clc, clear all;
M = 16; % Modulation Order || same that Max value, at your case: 256! 2^m
hEnc = comm.RSEncoder;
hEnc.CodewordLength = M - 1; % Max = M-1, Min = 4, Must be greater than MessageLenght
hEnc.MessageLength = 13; % Experiment change up and down value (using odd number)
hEnc.BitInput = false;
hEnc
t = hEnc.CodewordLength - hEnc.MessageLength;
frame = 2*hEnc.MessageLength; % multiple of MensagemLength
fprintf('\tError Detection (in Symbols): %d\n',t);
fprintf('\tError Correction: %.2f\n',t/2);
data = randi([0 M-1], frame, 1); % Create a frame with symbols range (0 to M-1)
encodedData = step(hEnc, data); % encod the frame
Quick MATLAB question.
What would be the best/most efficient way to select a certain number of elements, 'n' in windows of 'm'. In other words, I want to select the first 50 elements of a sequence, then elements 10-60, then elements 20-70 ect.
Right now, my sequence is in vector format(but this can easily be changed).
EDIT:
The sequences that I am dealing with are too long to be stored in my RAM. I need to be able to create the windows, and then call upon the window that I want to analyze/preform another command on.
Do you have enough RAM to store a 50-by-nWindow array in memory? In that case, you can generate your windows in one go, and then apply your processing on each column
%# idxMatrix has 1:50 in first col, 11:60 in second col etc
idxMatrix = bsxfun(#plus,(1:50)',0:10:length(yourVector)-50); %'#
%# reshapedData is a 50-by-numberOfWindows array
reshapedData = yourVector(idxMatrix);
%# now you can do processing on each column, e.g.
maximumOfEachWindow = max(reshapedData,[],1);
To complement Kerrek's answer: if you want to do it in a loop, you can use something like
n = 50
m = 10;
for i=1:m:length(v)
w = v(i:i+n);
% Do something with w
end
There's a slight issue with the description of your problem. You say that you want "to select the first 50 elements of a sequence, then elements 10-60..."; however, this would translate to selecting elements:
1-50
10-60
20-70
etc.
That first sequence should be 0-10 to fit the pattern which of course in MATLAB would not make sense since arrays use one-indexing. To address this, the algorithm below uses a variable called startIndex to indicate which element to start the sequence sampling from.
You could accomplish this in a vectorized way by constructing an index array. Create a vector consisting of the starting indices of each sequence. For reuse sake, I put the length of the sequence, the step size between sequence starts, and the start of the last sequence as variables. In the example you describe, the length of the sequence should be 50, the step size should be 10 and the start of the last sequence depends on the size of the input data and your needs.
>> startIndex = 10;
>> sequenceSize = 5;
>> finalSequenceStart = 20;
Create some sample data:
>> sampleData = randi(100, 1, 28)
sampleData =
Columns 1 through 18
8 53 10 82 82 73 15 66 52 98 65 81 46 44 83 9 14 18
Columns 19 through 28
40 84 81 7 40 53 42 66 63 30
Create a vector of the start indices of the sequences:
>> sequenceStart = startIndex:sequenceSize:finalSequenceStart
sequenceStart =
10 15 20
Create an array of indices to index into the data array:
>> index = cumsum(ones(sequenceSize, length(sequenceStart)))
index =
1 1 1
2 2 2
3 3 3
4 4 4
5 5 5
>> index = index + repmat(sequenceStart, sequenceSize, 1) - 1
index =
10 15 20
11 16 21
12 17 22
13 18 23
14 19 24
Finally, use this index array to reference the data array:
>> sampleData(index)
ans =
98 83 84
65 9 81
81 14 7
46 18 40
44 40 53
Use (start : step : end) indexing: v(1:1:50), v(10:1:60), etc. If the step is 1, you can omit it: v(1:50).
Consider the following vectorized code:
x = 1:100; %# an example sequence of numbers
nwind = 50; %# window size
noverlap = 40; %# number of overlapping elements
nx = length(x); %# length of sequence
ncol = fix((nx-noverlap)/(nwind-noverlap)); %# number of sliding windows
colindex = 1 + (0:(ncol-1))*(nwind-noverlap); %# starting index of each
%# indices to put sequence into columns with the proper offset
idx = bsxfun(#plus, (1:nwind)', colindex)-1; %'
%# apply the indices on the sequence
slidingWindows = x(idx)
The result (truncated for brevity):
slidingWindows =
1 11 21 31 41 51
2 12 22 32 42 52
3 13 23 33 43 53
...
48 58 68 78 88 98
49 59 69 79 89 99
50 60 70 80 90 100
In fact, the code was adapted from the now deprecated SPECGRAM function from the Signal Processing Toolbox (just do edit specgram.m to see the code).
I omitted parts that zero-pad the sequence in case the sliding windows do not evenly divide the entire sequence (for example x=1:105), but you can easily add them again if you need that functionality...