Run for loop and print data after each iteration

Question

monkey_matlab 2015-10-6

0
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此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/247093-run-for-loop-and-print-data-after-each-iteration

编辑： Kirby Fears 2015-10-6

data.txt

Hello, in my attached Matlab Code, I would like to run the for loop to carry out the calculation on each of the DataX and then print the result after each iteration. So after my first run of the for loop, the result should be: " At Freq 136, the sum of volt 1 = 55. Can you tell me what I am doing wrong? Here is my code:

% Select file
clear;
clc;
[FileName,PathName] = uigetfile('*.txt','Select data file');
fid = fopen( strcat(PathName,FileName) ,'rt' );
% Read the file and store into matrix v
i = 0;
v = [0 0];
while feof(fid) == 0
    buffer = fscanf(fid, '%f', 5);
    buffer = buffer';
    if i == 0;
        v = buffer;
    else
        v = vertcat(v,buffer);
    end
    i = i + 1;
end
% Frequency vector
freq = v(:,1);
% Data 1
Data1 = v(2:end,2);
Freq1 = v(1,2);
% Data 2
Data2 = v(2:end,3);
Freq2 = v(1,3);
% Data 3
Data3 = v(2:end,4);
Freq3 = v(1,4);
% Step 1-Convert y-data from power to volts
for ii = 1:3,
    volt_ii = sqrt(10.^(Dataii./10));
    summer_ii = sum(volt_ii);
    printf('At Freq %d, the sum of volt %d = %d', Freqii, ii, summer_ii);
    ii = +ii;
end

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Answer 1

Kirby Fears 2015-10-6

2
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/247093-run-for-loop-and-print-data-after-each-iteration#answer_194927

编辑：Kirby Fears 2015-10-6

在 MATLAB Online 中打开

Hi monkey_matlab,

When you write "volt_ii" (or "Dataii") Matlab will not resolve it to volt_1 (or Data1). Matlab reads this as a variable literally named volt_ii which is the same on every iteration of your loop. If you want Matlab to resolve the name, you'd need to write something like

eval(['volt_',num2str(ii)]);

Realistically you don't need to use this approach at all. Everything after your while-loop can be done this way instead:

vFreq = v(1,2:4);
vData = v(2:end,2:4);
for ii=1:size(vData,2),
    tempVolt = sqrt(10.^(vData(:,ii)./10));
    tempSum = sum(tempVolt);
    printStr=sprintf('At Freq %d, the sum of volt %d = %d',...
        vFreq(ii), ii, tempSum);
    disp(printStr);
end,