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  • cell and array in Matlab

    - by Tim
    Hi, I am a little confused about the usage of cell and array in Matlab. I would like to hear about your understandings. Here are my observations: (1). array can dynamically adjust its own memory to allow dynamic number of elements, while cell seems not act in the same way. a=[]; a=[a 1]; b={}; b={b 1}; (2). several elements can be retrieved from cell, while they seem not from array. a={'1' '2'}; figure, plot(...); hold on; plot(...) ; legend(a{1:2}); b=['1' '2']; figure, plot(...); hold on; plot(...) ; legend(b(1:2)); % b(1:2) is an array, not its elements, so it is wrong with legend. Are these correct? What are some other different usages between the cell and array? Thanks and regards!

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  • Import & modify date data in MATLAB

    - by niko
    I have a .csv file with records written in the following form: 2010-04-20 15:15:00,"8.9915176259e+00","8.8562623697e+00" 2010-04-20 15:30:00,"8.5718021723e+00","8.6633827160e+00" 2010-04-20 15:45:00,"8.4484844117e+00","8.4336586330e+00" 2010-04-20 16:00:00,"1.1106980342e+01","8.4333062208e+00" 2010-04-20 16:15:00,"9.0643470589e+00","8.6885660103e+00" 2010-04-20 16:30:00,"8.2133517943e+00","8.2677822671e+00" 2010-04-20 16:45:00,"8.2499419380e+00","8.1523501983e+00" 2010-04-20 17:00:00,"8.2948492278e+00","8.2884797924e+00" From these data I would like to make clusters - I would like to add a column with number indicating the hour - so in case of the first row a value 15 has to be added in a new row. The first problem is that calling a function [numData, textData, rawData] = xlsread('testData.csv') creates an empty matrix numData and one-column textData and rawData structures. Is it possible to create any template which recognizes a yyyy, MM, dd, hh, mm, ss values from the data above? What I would basically like to do with these data is to categorize the values by hours so from the example row of input: 2010-04-20 15:15:00,"8.9915176259e+00","8.8562623697e+00" update 1: in Matlab the line above is recognized as a string: '2010-04-26 13:00:00,"1.0428104753e+00","2.3456394130e+00"' I would want this to be the output: 15, 8.9915176259e+00, 8.8562623697e+00 update 1: a string has to be parsed Does anyone know how to parse a string and retrieve a timestamp, value1 (1.0428104753e+00) and value2 (2.3456394130e+00) from it as separate values?

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  • Combining two data sets and plotting in matlab

    - by bautrey
    I am doing experiments with different operational amplifier circuits and I need to plot my measured results onto a graph. I have two data sets: freq1 = [.1 .2 .5 .7 1 3 4 6 10 20 35 45 60 75 90 100]; %kHz Vo1 = [1.2 1.6 1.2 2 2 2.4 14.8 20.4 26.4 30.4 53.6 68.8 90 114 140 152]; %mV V1 = 19.6; Acm = Vo1/(1000*V1); And: freq2 = [.1 .5 1 30 60 70 85 100]; %kHz Vo1 = [3.96 3.96 3.96 3.84 3.86 3.88 3.88 3.88]; %V V1 = .96; Ad = Vo1/(2*V1); (I would show my plots but apparently I need more reps for that) I need to plot the equation, CMRR vs freq: CMRR = 20*log10(abs(Ad/Acm)); The size of Ad and Acm are different and the frequency points do not match up, but the boundaries of both of these is the same, 100Hz to 100kHz (x-axis). On the line of CMRR, Matlab says that Ad and Acm matrix dimensions do not agree. How I think I would solve this is using freq1 as the x-axis for CMRR and then taking approximated points from Ad according to the value on freq1. Or I could do function approximations of Ad and Acm and then do the divide operator on those. I do not know how I would code up this two ideas. Any other ideas would helpful, especially simpler ones. Thanks

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  • Converting Single dimensional vector or array to two dimension in Matlab

    - by pac
    Well I do not know if I used the exact term. I tried to find an answer on the net. Here is what i need: I have a vector a = 1 4 7 2 5 8 3 6 9 If I do a(4) the value is 4. So it is reading first column top to buttom then continuing to next .... I don't know why. However, What I need is to call it using two indices. As row and column: a(3,2)= 4 or even better if i can call it in the following way: a{3}(2)=4 What is this process really called (want to learn) and how to perform in matlab. I thought of a loop. Is there a built in function Thanks a lot Check this: a = 18 18 16 18 18 18 16 0 0 0 16 16 18 0 18 16 0 18 18 16 18 0 18 18 0 16 0 0 0 18 18 0 18 18 16 0 16 0 18 18 >> a(4) ans = 18 >> a(5) ans = 18 >> a(10) ans = 18 I tried reshape. it is reshaping not converting into 2 indeces

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  • Matlab fft function

    - by CTZStef
    The code below is from the Matlab 2011a help about fft function. I think there is a problem here : why do they multiply t(1:50) by Fs, and then say it's time in millisecond ? Certainly, it happens to be true in this very particular case, but change the value of Fs to, say, 2000, and it won't work anymore, obviously because of this factor of 2. Right ? Quite misleading, isn't it ? What do I miss ? Fs = 1000; % Sampling frequency T = 1/Fs; % Sample time L = 1000; % Length of signal t = (0:L-1)*T; % Time vector % Sum of a 50 Hz sinusoid and a 120 Hz sinusoid x = 0.7*sin(2*pi*50*t) + sin(2*pi*120*t); y = x + 2*randn(size(t)); % Sinusoids plus noise plot(Fs*t(1:50),y(1:50)) title('Signal Corrupted with Zero-Mean Random Noise') xlabel('time (milliseconds)') Clearer with this : fs = 2000; % Sampling frequency T = 1 / fs; % Sample time L = 1000; % Length of signal t2 = (0:L-1)*T; % Time vector f = 50; % signal frequency s2 = sin(2*pi*f*t2); figure, plot(fs*t2(1:50),s2(1:50)); % NOT good figure, plot(t2(1:50),s2(1:50)); % good

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  • MATLAB: svds() not converging

    - by Paul
    So using MATLAB's svds() function on some input data as such: [U, S, V, flag] = svds(data, nSVDs, 'L') I noticed that from run to run with the same data, I'd get drastically different output SVD sizes from run to run. When I checked whether 'flag' was set, I found that it was, indicating that the SVDs had not converged. My normal system here would be that if it really needs to converge, I'd do something like this: flag = 1 svdOpts = struct('tol', 1e-10, 'maxit', 600, 'disp', 0); while flag: if svdOpts.maxit > 1e6 error('There''s a real problem here.') end [U, S, V, flag] = svds(data, nSVDs, 'L', svdOpts) svdOpts.maxit = svdOpts.maxit*2 end But from what I can tell, when you use 'L' as the third argument, the fourth argument is ignored, meaning I just have to deal with the fact that it's not converging? I'm not even really sure how to use the 'sigma' argument in place of the 'L' argument. I've also tried reducing the number of SVDs calculated to no avail. Any help on this matter would be much appreciated. EDIT While following up on the comments below, I found that the problem had to do with the way I was building my data matrices. Turned out I had accidentally inverted a matrix and had an input of size (4000x1) rather than (20x200), which was what was refusing to converge. I also did some more timing tets and found that the fourth argument was not, in fact, being ignored, so that's on me. Thanks for the help guys.

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  • Error in bisection method code in Matlab

    - by Amanda Collins
    I need to write a proper implementation of the bisection method, which means I must address all possible user input errors. Here is my code: function [x_sol, f_at_x_sol, N_iterations] = bisection(f, xn, xp, eps_f, eps_x) % solving f(x)=0 with bisection method % f is the function handle to the desired function, % xn and xp are borders of search, % f(xn)<0 and f(xp)>0 required, % eps_f defines how close f(x) should be to zero, % eps_x defines uncertainty of solution x if(f(xp) < 0) error('xp must be positive') end; if(f(xn)>0) error('xn must be negative') end; if (xn >= xp) error ('xn must be less than xp') end; xg=(xp+xn)/2; %initial guess fg=f(xg); % initial function evaluation N_iterations=1; while ( (abs(fg) > eps_f) & (abs(xg-xp) > eps_x) ) if (fg>0) xp=xg; else xn=xg; end xg=(xp+xn)/2; %update guess fg=f(xg); %update function evaluation N_iterations=N_iterations+1; end x_sol=xg; %solution is ready f_at_x_sol=fg; if (f_at_x_sol > eps_f) error('No convergence') end and here is the error message I receive when I try to test this in Matlab: >> bisection(x.^2, 2, -1, 1e-8, 1e-10) Attempted to access f(-1); index must be a positive integer or logical. Error in bisection (line 9) if(f(xp)<0) I was attempting to see if my error codes worked, but it doesn't look like they do. I get the same error when I try to test it on a function that should work.

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  • Stop writing blank line at the end of CSV file (using MATLAB)

    - by Grant M.
    Hello all ... I'm using MATLAB to open a batch of CSV files containing column headers and data (using the 'importdata' function), then I manipulate the data a bit and write the headers and data to new CSV files using the 'dlmwrite' function. I'm using the '-append' and 'newline' attributes of 'dlmwrite' to add each line of text/data on a new line. Each of my new CSV files has a blank line at the end, whereas this blank line was not there before when I read in the data ... and I'm not using 'newline' on my final call of 'dlmwrite'. Does anyone know how I can keep from writing this blank line to the end of my CSV files? Thanks for your help, Grant EDITED 5/18/10 1:35PM CST - Added information about code and text file per request ... you'll notice after performing the procedure below that there appears to be a carriage return at the end of the last line in the new text file. Consider a text file named 'textfile.txt' that looks like this: Column1, Column2, Column3, Column4, Column 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 1, 2, 3, 4, 5 Here's a sample of the code I am using: % import data importedData = importdata('textfile.txt'); % manipulate data importedData.data(:,1) = 100; % store column headers into single comma-delimited % character array (for easy writing later) columnHeaders = importedData.textdata{1}; for counter = 2:size(importedData.textdata,2) columnHeaders = horzcat(columnHeaders,',',importedData.textdata{counter}); end % write column headers to new file dlmwrite('textfile_updated.txt',columnHeaders,'Delimiter','','newline','pc') % append all but last line of data to new file for dataCounter = 1:(size(importedData.data,2)-1) dlmwrite('textfile_updated.txt',importedData.data(dataCounter,:),'Delimiter',',','newline','pc','-append') end % append last line of data to new file, not % creating new line at end dlmwrite('textfile_updated.txt',importedData.data(end,:),'Delimiter',',','-append')

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  • Determining two lines in MATLAB

    - by Sanyi
    Hi! I am making the game planarity in MATLAB, and i am stuck where the program have to determine that is there any lines that are in inscision with each other. Any ideas how could the program find the inscision points. Heres my source for the game: > clear; clc; a=1; b=10; x=floor(rand(5,1)*(b-a+1)+a); y=floor(rand(5,1)*(b-a+1)+a); fig1=figure; set(fig1,'Color','w','Position',[100 100 500 500]) plot(x,y,'o','MarkerSize',12,'MarkerFaceColor','r'); axis([0 11 0 11]); axis off grid on; hold on; FirstPlayerLines=[]; SecondPlayerLines=[]; for a1=1:+1:2 for a2=5:-1:2 plot([x(a1) x(a2)],[y(a1) y(a2)],'Color','black','LineWidth',3); end end waitforbuttonpress

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  • Matlab GUI: How to Save the Results of Functions (states of application)

    - by niko
    Hi, I would like to create an animation which enables the user to go backward and forward through the steps of simulation. An animation has to simulate the iterative process of channel decoding (a receiver receives a block of bits, performs an operation and then checks if the block corresponds to parity rules. If the block doesn't correspond the operation is performed again and the process finally ends when the code corresponds to a given rules). I have written the functions which perform the decoding process and return a m x n x i matrix where m x n is the block of data and i is the iteration index. So if it takes 3 iterations to decode the data the function returns a m x n x 3 matrix with each step is stired. In the GUI (.fig file) I put a "decode" button which runs the method for decoding and there are buttons "back" and "forward" which have to enable the user to switch between the data of recorded steps. I have stored the "decodedData" matrix and currentStep value as a global variable so by clicking "forward" and "next" buttons the indices have to change and point to appropriate step states. When I tried to debug the application the method returned the decoded data but when I tried to click "back" and "next" the decoded data appeared not to be declared. Does anyone know how is it possible to access (or store) the results of the functions in order to enable the described logic which I want to implement in Matlab GUI?

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  • Problem with Matlab functions

    - by appi
    HI. I got this matlab functionWhen I ran it, the following error messege showed up. Can anybody give me some hint? Thank you. The code is also shown below. [h,im_matched,theta,I,J]=im_reg_MI('keyframe1.jpg','keyframe2.jpg', 0, 1) ??? Undefined function or variable "h". Error in == im_reg_MI at 74 [a, b] = max(h(:));% finding the max of MI and indecises Below is the code. [h,im_matched, theta,I,J]=im_reg_MI(image1, image2, angle, step) [m,n]=size(image1); [p,q]=size(image2); [a,b]=size(angle); im1=round(image1); for k=1:b J = rotate_image(angle(k),image2); %rotated cropped IMAGE2 image21=round(J); [m1,n1]=size(image21); for i=1:step:(m1-m) for j=1:step:(n1-n) im2=image21(i:(i+m-1),j:(j+n-1)); % selecting part of IMAGE2 matching the size of IMAHE1 im2=round(im2); h(k,i,j)=MI2(im1,im2); % calculating MI end end end [a, b] = max(h(:));% finding the max of MI and indecises

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  • Matlab Coin Toss Simulation

    - by user1772959
    I have to write some code in Matlab that simulates tossing a coin 150 times. I have to count how many times the coin lands on heads and create a vector that gives a running percentage of the heads. Then I have to make a table of the number of trials, random 'flips", and the running percentages of heads. I assume random "flips" means heads or tails for that trial. I also have to create a line graph with trials on the x-axis and probabilities (percentages) on the y-axis. I'm assuming the percentages are just the percentage of getting heads. Sorry if this post was long. I figure giving the details now will make it easier to see what I was trying to do with the code. I didn't create the table or plot yet because I'm not even sure how to code for the actual problem. NUM_TRIALS = 150; trials = 1:NUM_TRIALS; heads = 0; t = rand(NUM_TRIALS,1); for i = trials if (t < 0.5) heads = heads + 1; end z = zeros(NUM_TRIALS,1); percent_h = heads/trials; end

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  • MATLAB, time match filter

    - by Paul
    OK, I am still getting the hang of MATLAB. I have two files in different format. One Excel file. data1.xls, size= 86400 X 62. It looks like: Date/Time par1 par2 par3 par4 par5 par6 par6 par7 par8 par9 08/02/09 00:06:45 0 3 27 9.9 -133.2 0 0 0 1 0 Another file, data2.csv, size = 144 X 27. (If nothing is missing.) It looks like: date time P01 P02 P03 P04 P05 P06 P07 P08 P09 P10 P11 8/16/2009 0:00 51 45 46 54 53 52 524 5 399 89 78 Now I am using Data10minAvg = mean(reshape(Data,300,144,62)); to get the 10 min average of the first Excel file. Now I need to match up that file I am making above with the .csv file. The problem is many timestamps are missing in the .csv file. How do I make data2.csv into a file of size 144 X 27, replacing the missing datestamps by rows of zero? It will really help me than compare data1.xls file with newdata2.csv.

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  • Effective simulation of compound poisson process in Matlab

    - by Henrik
    I need to simulate a huge bunch of compound poisson processes in Matlab on a very fine grid so I am looking to do it most effectively. I need to do a lot of simulations on the same random numbers but with parameters changing so it is practical to draw the uniforms and normals beforehand even though it means i have to draw a lot more than i will probably need and won't matter much because it will only need to be done once compared to in the order 500*n repl times the actual compound process generation. My method is the following: Let T be for how long i need to simulate and N the grid points, then my grid is: t=linspace(1,T,N); Let nrepl be the number of processes i need then I simulate P=poissrnd(lambda,nrepl,1); % Number of jumps for each replication U=(T-1)*rand(10000,nrepl)+1; % Set of uniforms on (1,T) for jump times N=randn(10000,nrepl); % Set of normals for jump size Then for replication j: Poiss=P(j); % Jumps for replication Uni=U(1:Poiss,j);% Jump times Norm=mu+sigma*N(1:Poiss,j);% Jump sizes Then this I guess is where I need your advice, I use this one-liner but it seems very slow: CPP_norm=sum(bsxfun(@times,bsxfun(@gt,t,Uni),Norm),1); In the inner for each jump it creates a series of same length as t with 0 until jump and then 1 after, multiplying this will create a grid with zeroes until jump has arrived and then the jump size and finally adding all these will produce the entire jump process on the grid. How can this be done more effectively? Thank you very much.

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  • reformatting a matrix in matlab with nan values

    - by Kate
    This post follows a previous question regarding the restructuring of a matrix: re-formatting a matrix in matlab An additional problem I face is demonstrated by the following example: depth = [0:1:20]'; data = rand(1,length(depth))'; d = [depth,data]; d = [d;d(1:20,:);d]; Here I would like to alter this matrix so that each column represents a specific depth and each row represents time, so eventually I will have 3 rows (i.e. days) and 21 columns (i.e. measurement at each depth). However, we cannot reshape this because the number of measurements for a given day are not the same i.e. some are missing. This is known by: dd = sortrows(d,1); for i = 1:length(depth); e(i) = length(dd(dd(:,1)==depth(i),:)); end From 'e' we find that the number of depth is different for different days. How could I insert a nan into the matrix so that each day has the same depth values? I could find the unique depths first by: unique(d(:,1)) From this, if a depth (from unique) is missing for a given day I would like to insert the depth to the correct position and insert a nan into the respective location in the column of data. How can this be achieved?

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  • Matlab multiple graph types inside one graph

    - by mirekys
    Hi, I have a task to draw electrostatic field between two electrodes( at given sizes and shape ), what i have now is that i draw the electrodes with area plot (area(elect_x,elect_y)) the graph looks like this: ------------------.--- |.. .---. |.. |...| |.. .----....| |.. |........| |.. ---------------------- and now i would need to draw inside this probably a mesh, showing the field. Is there any way to do it, or i´m on a wrong way? Thank you very much for every guide

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  • Matlab N-Queen Problem

    - by Kay
    main.m counter = 1; n = 8; board = zeros(1,n); back(0, board); disp(counter); sol.m function value = sol(board) for ( i = 1:(length(board))) for ( j = (i+1): (length(board)-1)) if (board(i) == board(j)) value = 0; return; end if ((board(i) - board(j)) == (i-j)) value = 0; return; end if ((board(i) - board(j)) == (j-i)) value = 0; return; end end end value = 1; return; back.m function back(depth, board) disp(board); if ( (depth == length(board)) && (sol2(board) == 1)) counter = counter + 1; end if ( depth < length(board)) for ( i = 0:length(board)) board(1,depth+1) = i; depth = depth + 1; solv2(depth, board); end end I'm attempting to find the maximum number of ways n-queen can be placed on an n-by-n board such that those queens aren't attacking eachother. I cannot figure out the problem with the above matlab code, i doubt it's a problem with my logic since i've tested out this logic in java and it seems to work perfectly well there. The code compiles but the issue is that the results it produces are erroneous. Java Code which works: public static int counter=0; public static boolean isSolution(final int[] board){ for (int i = 0; i < board.length; i++) { for (int j = i + 1; j < board.length; j++) { if (board[i] == board[j]) return false; if (board[i]-board[j] == i-j) return false; if (board[i]-board[j] == j-i) return false; } } return true; } public static void solve(int depth, int[] board){ if (depth == board.length && isSolution(board)) { counter++; } if (depth < board.length) { // try all positions of the next row for (int i = 0; i < board.length; i++) { board[depth] = i; solve(depth + 1, board); } } } public static void main(String[] args){ int n = 8; solve(0, new int[n]); System.out.println(counter); }

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  • SET game odds simulation (MATLAB)

    - by yuk
    Here is an interesting problem for your weekend. :) I recently find the great card came - SET. Briefly, there are 81 cards with the four features: symbol (oval, squiggle or diamond), color (red, purple or green), number (one, two or three) or shading (solid, striped or open). The task is to find (from selected 12 cards) a SET of 3 cards, in which each of the four features is either all the same on each card or all different on each card (no 2+1 combination). In my free time I've decided to code it in MATLAB to find a solution and to estimate odds of having a set in randomly selected cards. Here is the code: %% initialization K = 12; % cards to draw NF = 4; % number of features (usually 3 or 4) setallcards = unique(nchoosek(repmat(1:3,1,NF),NF),'rows'); % all cards: rows - cards, columns - features setallcomb = nchoosek(1:K,3); % index of all combinations of K cards by 3 %% test tic NIter=1e2; % number of test iterations setexists = 0; % test results holder % C = progress('init'); % if you have progress function from FileExchange for d = 1:NIter % C = progress(C,d/NIter); % cards for current test setdrawncardidx = randi(size(setallcards,1),K,1); setdrawncards = setallcards(setdrawncardidx,:); % find all sets in current test iteration for setcombidx = 1:size(setallcomb,1) setcomb = setdrawncards(setallcomb(setcombidx,:),:); if all(arrayfun(@(x) numel(unique(setcomb(:,x))), 1:NF)~=2) % test one combination setexists = setexists + 1; break % to find only the first set end end end fprintf('Set:NoSet = %g:%g = %g:1\n', setexists, NIter-setexists, setexists/(NIter-setexists)) toc 100-1000 iterations are fast, but be careful with more. One million iterations takes about 15 hours on my home computer. Anyway, with 12 cards and 4 features I've got around 13:1 of having a set. This is actually a problem. The instruction book said this number should be 33:1. And it was recently confirmed by Peter Norvig. He provides the Python code, but I didn't test it. So can you find an error?

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  • Simplifying a four-dimensional rule table in Matlab: addressing rows and columns of each dimension

    - by Cate
    Hi all. I'm currently trying to automatically generate a set of fuzzy rules for a set of observations which contain four values for each observation, where each observation will correspond to a state (a good example is with Fisher's Iris Data). In Matlab I am creating a four dimensional rule table where a single cell (a,b,c,d) will contain the corresponding state. To reduce the table I am following the Hong and Lee method of row and column similarity checking but I am having difficulty understanding how to address the third and fourth dimensions' rows and columns. From the method it is my understanding that each dimension is addressed individually and if the rule is true, the table is simplified. The rules for merging are as follows: If all cells in adjacent columns or rows are the same. If two cells are the same or if either of them is empty in adjacent columns or rows and at least one cell in both is not empty. If all cells in a column or row are empty and if cells in its two adjacent columns or rows are the same, merge the three. If all cells in a column or row are empty and if cells in its two adjacent columns or rows are the same or either of them is empty, merge the three. If all cells in a column or row are empty and if all the non-empty cells in the column or row to its left have the same region, and all the non-empty cells in the column or row to its right have the same region, but one different from the previously mentioned region, merge these three columns into two parts. Now for the confusing bit. Simply checking if the entire row/column is the same as the adjacent (rule 1) seems simple enough: if (a,:,:,:) == (a+1,:,:,:) (:,b,:,:) == (:,b+1,:,:) (:,:,c,:) == (:,:,c+1,:) (:,:,:,d) == (:,:,:,d+1) is this correct? but to check if the elements in the row/column match, or either is zero (rules 2 and 4), I am a bit lost. Would it be something along these lines: for a = 1:20 for i = 1:length(b) if (a+1,i,:,:) == (a,i,:,:) ... else if (a+1,i,:,:) == 0 ... else if (a,i,:,:) == 0 etc. and for the third and fourth dimensions: for c = 1:20 for i = 1:length(a) if (i,:,c,:) == (i,:,c+1,:) ... else if (i,:,c+1,:) == 0 ... else if (i,:,c,:) == 0 etc. for d = 1:20 for i = 1:length(a) if (i,:,:,d) == (i,:,:,d+1) ... else if (i,:,:,d+1) == 0 ... else if (i,:,:,d) == 0 etc. even any help with four dimensional arrays would be useful as I'm so confused by the thought of more than three! I would advise you look at the paper to understand my meaning - they themselves have used the Iris data but only given an example with a 2D table. Thanks in advance, hopefully!

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  • MATLAB image corner coordinates & referncing to cell arrays

    - by James
    Hi, I am having some problems comparing the elements in different cell arrays. The context of this problem is that I am using the bwboundaries function in MATLAB to trace the outline of an image. The image is of a structural cross section and I am trying to find if there is continuity throughout the section (i.e. there is only one outline produced by the bwboundaries command). Having done this and found where the is more than one section traced (i.e. it is not continuous), I have used the cornermetric command to find the corners of each section. The code I have is: %% Define the structural section as a binary matrix (Image is an I-section with the web broken) bw(20:40,50:150) = 1; bw(160:180,50:150) = 1; bw(20:60,95:105) = 1; bw(140:180,95:105) = 1; Trace = bw; [B] = bwboundaries(Trace,'noholes'); %Traces the outer boundary of each section L = length(B); % Finds number of boundaries if L > 1 disp('Multiple boundaries') % States whether more than one boundary found end %% Obtain perimeter coordinates for k=1:length(B) %For all the boundaries perim = B{k}; %Obtains perimeter coordinates (as a 2D matrix) from the cell array end %% Find the corner positions C = cornermetric(bw); Areacorners = find(C == max(max(C))) % Finds the corner coordinates of each boundary [rowindexcorners,colindexcorners] = ind2sub(size(Newgeometry),Areacorners) % Convert corner coordinate indexes into subcripts, to give x & y coordinates (i.e. the same format as B gives) %% Put these corner coordinates into a cell array Cornerscellarray = cell(length(rowindexcorners),1); % Initialises cell array of zeros for i =1:numel(rowindexcorners) Cornerscellarray(i) = {[rowindexcorners(i) colindexcorners(i)]}; %Assigns the corner indicies into the cell array %This is done so the cell arrays can be compared end for k=1:length(B) %For all the boundaries found perim = B{k}; %Obtains coordinates for each perimeter Z = perim; % Initialise the matrix containing the perimeter corners Sectioncellmatrix = cell(length(rowindexcorners),1); for i =1:length(perim) Sectioncellmatrix(i) = {[perim(i,1) perim(i,2)]}; end for i = 1:length(perim) if Sectioncellmatrix(i) ~= Cornerscellarray Sectioncellmatrix(i) = []; %Gets rid of the elements that are not corners, but keeps them associated with the relevent section end end end This creates an error in the last for loop. Is there a way I can check whether each cell of the array (containing an x and y coordinate) is equal to any pair of coordinates in cornercellarray? I know it is possible with matrices to compare whether a certain element matches any of the elements in another matrix. I want to be able to do the same here, but for the pair of coordinates within the cell array. The reason I don't just use the cornercellarray cell array itself, is because this lists all the corner coordinates and does not associate them with a specific traced boundary.

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  • The Beginner’s Guide to Managing Users and Groups in Linux

    - by Zainul Franciscus
    Ubuntu Linux uses groups to help you manage users, set permissions on those users, and even monitor how much time they are spending in front of the PC. Here’s a beginner’s guide to how it all works Latest Features How-To Geek ETC The How-To Geek Holiday Gift Guide (Geeky Stuff We Like) LCD? LED? Plasma? The How-To Geek Guide to HDTV Technology The How-To Geek Guide to Learning Photoshop, Part 8: Filters Improve Digital Photography by Calibrating Your Monitor Our Favorite Tech: What We’re Thankful For at How-To Geek The How-To Geek Guide to Learning Photoshop, Part 7: Design and Typography Happy Snow Bears Theme for Chrome and Iron [Holiday] Download Full Command and Conquer: Tiberian Sun Game for Free Scorched Cometary Planet Wallpaper Quick Fix: Add the RSS Button Back to the Firefox Awesome Bar Dropbox Desktop Client 1.0.0 RC for Windows, Linux, and Mac Released Hang in There Scrat! – Ice Age Wallpaper

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  • Upcoming Customer WebCast: SOA 11g Database: Guide for Administrators

    - by MariaSalzberger
    The SOA infrastructure database is used by SOA Suite products like BPEL PM, BAM, BPM, Human Worklow, B2B and Mediator. A SOA administrator is involved in many different tasks like installation, upgrade, performance tuning and other administrative topics. Another important one is purging - see the posting for this: SOA Suite 11g Purging Guide. We have implemented a guide to help with thess tasks: SOA 11g Infrastructure Database: Installation, Maintenance and Administration Guide. An upcoming advisor webcast planned for Wednesday, April 11 2012 at 15:00 UK / 16:00 CET / 07:00 am Pacific / 8:00 am Mountain / 10:00 am Eastern will walk you through the guide and show some of the highligts. Registration for this webcast is available in SOA 11g Database: Guide for Administrators [ID 1422913.1]. The presentation recording can by found here after the webcast. (https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&doctype=ANNOUNCEMENT&id=740964.1) The schedule for future webcasts can be found here (https://support.oracle.com/CSP/main/article?cmd=show&type=NOT&doctype=ANNOUNCEMENT&id=740966.1)

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  • Scale image to fit text boxes around borders

    - by nispio
    I have the following plot in Matlab: The image size may vary, and so may the length of the text boxes at the top and left. I dynamically determine the strings that go in these text boxes and then create them with: [M,N] = size(img); imagesc((1:N)-0.5,(1:M)-0.5, img > 0.5); axis image; grid on; colormap([1 1 1; 0.5 0.5 0.5]); set(gca,'XColor','k','YColor','k','TickDir','out') set(gca,'XTick',1:N,'XTickLabel',cell(1,N)) set(gca,'YTick',1:N,'YTickLabel',cell(1,N)) for iter = 1:M text(-0.5, iter-0.5, sprintf(strL, br{iter,:}), ... 'FontSize',16, ... 'HorizontalAlignment','right', ... 'VerticalAlignment','middle', ... 'Interpreter','latex' ); end for iter = 1:N text(iter-0.5, -0.5, {bc{:,iter}}, ... 'FontSize',16, ... 'HorizontalAlignment','center', ... 'VerticalAlignment','bottom', ... 'Interpreter','latex' ); end where br and bc are cell arrays containing the appropriate numbers for the labels. The problem is that most of the time, the text gets clipped by the edges of the figure. I am using this as a workaround: set(gca,'Position',[0.25 0.25 0.5 0.5]); As you can see, I am simply adding a larger border around the plot so that there is more room for the text. While this scaling works for one zoom level, if I maximize my plot window I get way too much empty space, and if I shrink my plot window, I get clipping again. Is there a more intelligent way to add these labels to use the minimum amount of space while making sure that the text does not get clipped?

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  • Matlab: Optimization by perturbing variable

    - by S_H
    My main script contains following code: %# Grid and model parameters nModel=50; nModel_want=1; nI_grid1=5; Nth=1; nRow.Scale1=5; nCol.Scale1=5; nRow.Scale2=5^2; nCol.Scale2=5^2; theta = 90; % degrees a_minor = 2; % range along minor direction a_major = 5; % range along major direction sill = var(reshape(Deff_matrix_NthModel,nCell.Scale1,1)); % variance of the coarse data matrix of size nRow.Scale1 X nCol.Scale1 %# Covariance computation % Scale 1 for ihRow = 1:nRow.Scale1 for ihCol = 1:nCol.Scale1 [cov.Scale1(ihRow,ihCol),heff.Scale1(ihRow,ihCol)] = general_CovModel(theta, ihCol, ihRow, a_minor, a_major, sill, 'Exp'); end end % Scale 2 for ihRow = 1:nRow.Scale2 for ihCol = 1:nCol.Scale2 [cov.Scale2(ihRow,ihCol),heff.Scale2(ihRow,ihCol)] = general_CovModel(theta, ihCol/(nCol.Scale2/nCol.Scale1), ihRow/(nRow.Scale2/nRow.Scale1), a_minor, a_major, sill/(nRow.Scale2*nCol.Scale2), 'Exp'); end end %# Scale-up of fine scale values by averaging [covAvg.Scale2,var_covAvg.Scale2,varNorm_covAvg.Scale2] = general_AverageProperty(nRow.Scale2/nRow.Scale1,nCol.Scale2/nCol.Scale1,1,nRow.Scale1,nCol.Scale1,1,cov.Scale2,1); I am using two functions, general_CovModel() and general_AverageProperty(), in my main script which are given as following: function [cov,h_eff] = general_CovModel(theta, hx, hy, a_minor, a_major, sill, mod_type) % mod_type should be in strings angle_rad = theta*(pi/180); % theta in degrees, angle_rad in radians R_theta = [sin(angle_rad) cos(angle_rad); -cos(angle_rad) sin(angle_rad)]; h = [hx; hy]; lambda = a_minor/a_major; D_lambda = [lambda 0; 0 1]; h_2prime = D_lambda*R_theta*h; h_eff = sqrt((h_2prime(1)^2)+(h_2prime(2)^2)); if strcmp(mod_type,'Sph')==1 || strcmp(mod_type,'sph') ==1 if h_eff<=a cov = sill - sill.*(1.5*(h_eff/a_minor)-0.5*((h_eff/a_minor)^3)); else cov = sill; end elseif strcmp(mod_type,'Exp')==1 || strcmp(mod_type,'exp') ==1 cov = sill-(sill.*(1-exp(-(3*h_eff)/a_minor))); elseif strcmp(mod_type,'Gauss')==1 || strcmp(mod_type,'gauss') ==1 cov = sill-(sill.*(1-exp(-((3*h_eff)^2/(a_minor^2))))); end and function [PropertyAvg,variance_PropertyAvg,NormVariance_PropertyAvg]=... general_AverageProperty(blocksize_row,blocksize_col,blocksize_t,... nUpscaledRow,nUpscaledCol,nUpscaledT,PropertyArray,omega) % This function computes average of a property and variance of that averaged % property using power averaging PropertyAvg=zeros(nUpscaledRow,nUpscaledCol,nUpscaledT); %# Average of property for k=1:nUpscaledT, for j=1:nUpscaledCol, for i=1:nUpscaledRow, sum=0; for a=1:blocksize_row, for b=1:blocksize_col, for c=1:blocksize_t, sum=sum+(PropertyArray((i-1)*blocksize_row+a,(j-1)*blocksize_col+b,(k-1)*blocksize_t+c).^omega); % add all the property values in 'blocksize_x','blocksize_y','blocksize_t' to one variable end end end PropertyAvg(i,j,k)=(sum/(blocksize_row*blocksize_col*blocksize_t)).^(1/omega); % take average of the summed property end end end %# Variance of averageed property variance_PropertyAvg=var(reshape(PropertyAvg,... nUpscaledRow*nUpscaledCol*nUpscaledT,1),1,1); %# Normalized variance of averageed property NormVariance_PropertyAvg=variance_PropertyAvg./(var(reshape(... PropertyArray,numel(PropertyArray),1),1,1)); Question: Using Matlab, I would like to optimize covAvg.Scale2 such that it matches closely with cov.Scale1 by perturbing/varying any (or all) of the following variables 1) a_minor 2) a_major 3) theta Thanks.

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  • "Invalid Handle Object" when plotting 2 figures Matlab

    - by pinnacler
    I'm having a difficult time understanding the paradigm of Matlab classes vs compared to c++. I wrote code the other day, and I thought it should work. It did not... until I added <handle after the classdef. So I have two classes, landmarks and robot, both are called from within the simulation class. This is the main loop of obj.simulation.animate() and it works, until I try to plot two things at once. DATA.path is a record of all the places a robot has been on the map, and it's updated every time the position is updated. When I try to plot it, by uncommenting the two marked lines below, I get this error: ??? Error using == set Invalid handle object. Error in == simulationsimulation.animate at 45 set(l.lm,'XData',obj.landmarks.apparentPositions(:,1),'YData',obj.landmarks.apparentPositions(:,2)); %INITIALIZE GLOBALS global DATA XX XX = [obj.robot.x ; obj.robot.y]; DATA.i=1; DATA.path = XX; %Setup Plots fig=figure; xlabel('meters'), ylabel('meters') set(fig, 'name', 'Phil''s AWESOME 80''s Robot Simulator') xymax = obj.landmarks.mapSize*3; xymin = -(obj.landmarks.mapSize*3); l.lm=scatter([0],[0],'b+'); %"UNCOMMENT ME"l.pth= plot(0,0,'k.','markersize',2,'erasemode','background'); % vehicle path axis([xymin xymax xymin xymax]); %Simulation Loop for n = 1:720, %Calculate and Set Heading/Location XX = [obj.robot.x;obj.robot.y]; store_data(XX); if n == 120, DATA.path end %Update Position headingChange = navigate(n); obj.robot.updatePosition(headingChange); obj.landmarks.updatePerspective(obj.robot.heading, obj.robot.x, obj.robot.y); %Animate %"UNCOMMENT ME" set(l.pth, 'xdata', DATA.path(1,1:DATA.i), 'ydata', DATA.path(2,1:DATA.i)); set(l.lm,'XData',obj.landmarks.apparentPositions(:,1),'YData',obj.landmarks.apparentPositions(:,2)); rectangle('Position',[-2,-2,4,4]); drawnow This is the classdef for landmarks classdef landmarks <handle properties fixedPositions; %# positions in a fixed coordinate system. [ x, y ] mapSize; %Map Size. Value is side of square x; y; heading; headingChange; end properties (Dependent) apparentPositions end methods function obj = landmarks(mapSize, numberOfTrees) obj.mapSize = mapSize; obj.fixedPositions = obj.mapSize * rand([numberOfTrees, 2]) .* sign(rand([numberOfTrees, 2]) - 0.5); end function apparent = get.apparentPositions(obj) currentPosition = [obj.x ; obj.y]; apparent = bsxfun(@minus,(obj.fixedPositions)',currentPosition)'; apparent = ([cosd(obj.heading) -sind(obj.heading) ; sind(obj.heading) cosd(obj.heading)] * (apparent)')'; end function updatePerspective(obj,tempHeading,tempX,tempY) obj.heading = tempHeading; obj.x = tempX; obj.y = tempY; end end end To me, this is how I understand things. I created a figure l.lm that has about 100 xy points. I can rotate this figure by using set(l.lm,'XData',obj.landmarks.apparentPositions(:,1),'YData',obj.landmarks.apparentPositions(:,2)); When I do that, things work. When I try to plot a second group of XY points, stored in DATA.path, it craps out and I can't figure out why.

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