Python MATLAB桥JSON

Question

我试图使用Python-到MATLAB桥，我不知道会发生什么。在

每次运行脚本时都会出现以下错误：

File "/Users/Casey/Desktop/ABOVE_TCP/Ingestion_software/test.py", line 8, in <module>
res = mlab.run('/Users/Casey/Desktop/ABOVE_TCP/Ingestion_software/jk.m', {'arg1': 3, 'arg2': 5, 'arg3': 4}, maxtime=20)
  File "/Users/Casey/Desktop/ABOVE_TCP/Ingestion_software/pymatbridge/__init__.py", line 85, in run
result = self._open_page(self.eval_func, page_args, maxtime)
   File "/Users/Casey/Desktop/ABOVE_TCP/Ingestion_software/pymatbridge/__init__.py", line 96, in _open_page
return json.loads(page.read())
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/__init__.py", line 338, in loads
return _default_decoder.decode(s)
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 365, in decode
obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/json/decoder.py", line 385, in raw_decode
    raise ValueError("No JSON object could be decoded")
ValueError: No JSON object could be decoded

然后我试着做GitHub页面前面给出的基本方法。这起作用了。 我慢慢地从另一个MATLAB脚本中复制和粘贴代码，直到我到达绘制图的地方，一旦我这样做了，我就不能再运行它了。它就是做不到，总是给我同样的错误，即使我删除了绘图代码。在

我进入并打印出了有问题的JSON对象，而out尝试将其转换为JSON，如下所示。在

^{pr2}$

我无法理解它的意义。我不知道。我只能从MATLAB运行这个脚本，它又胖又笨，而且很快乐。在

这里有Python和MATLAB代码。在

^{3}$

以及没有绘图的MATLAB代码：

function lol = jk(args)
    restoredefaultpath;
    clc;
    clear all;
    close all;
    clear functions;
    bdclose('all');
    fclose('all');
    arg1 = args.arg1
    arg2 = args.arg2
    arg3 = args.arg3
    fileName = '/Users/Casey/Desktop/MatlabTest/20140714_175009_cmrs_above_Full_Data.dat';
    summaryFileName =     '/Users/Casey/Desktop/MatlabTest/20140714_175009_cmrs_above_summary_plot.png';
    windowSize = 2048;
    overLap = windowSize * 0.75;
    sampleFreq = 150000;
    Window = hann(windowSize);

    dataFile = fopen(fileName);
    header = blanks(115);
    i = 1;
    %dataContents = fileread(fileName);
    dataContents = fread(dataFile);
    while i < 115
        char = dataContents(i);
        header(i) = char;
        if char == '}'
            break
        end
        i = i + 1;
    end
    header = header(2:i-1);
    headerSplit = strsplit(header,',');
    fileSize = str2double(headerSplit(17));
    fseek(dataFile, i + 0,'bof');
    Info = dir(fileName);
    Data = fread(dataFile,[Info.bytes 1], 'bit16', 0, 'b'); % Need to muliply filesize by 2 for final release
    fseek(dataFile, Info.bytes-10, 'bof');

    %Decide if end key check is needed, and what to do with it
    %endKey = textscan(dataFile, '%s');
    %endKey = endKey{1}{1};
    fclose(dataFile);

    Data = Data(1:fileSize/2);
    Chan1 = Data(1:2:end);
    Chan2 = Data(2:2:end);

    FFTChan1 = fft(Chan1, sampleFreq);
    FFTChan2 = fft(Chan2, sampleFreq);

    %iniliaze vectors for the polarizations
    LHC = zeros(length(FFTChan1),1);
    RHC = zeros(length(FFTChan1),1);
    TP = zeros(length(FFTChan1),1);


    for i = 1:length(FFTChan1)
        TP(i) = abs(FFTChan1(i))+abs(FFTChan2(i));
        RHC(i) = real(FFTChan1(i))+imag(FFTChan2(i));
        LHC(i) =real(FFTChan1(i))-imag(FFTChan2(i));
    end

    TPS = ifft(TP);
    RHCS = ifft(RHC);
    LHCS = ifft(LHC);
    maxTime = (length(Chan1)-1)/sampleFreq;


    lol = 'YYYUUUUUPPPPP';
    %lol = arg1 + arg2 + arg3;
end

现在开始策划。在

    %start making the plots!
    %set(gcf, 'Visible', 'off');
    %subplot(3,1,1);
    %spectrogram(TPS, Window, overLap,windowSize, sampleFreq, 'yaxis');
    %colorbar;
    %axis([0 maxTime 0 75000]);
    %title('Total Power');
    %subplot(3,1,2);
    %spectrogram(LHCS, Window, overLap,windowSize, sampleFreq, 'yaxis');
    %colorbar;
    %axis([0 maxTime 0 75000]);
    %title('Left Hand Cicular Polarization');

    %subplot(3,1,3);
    %spectrogram(RHCS, Window, overLap, windowSize, sampleFreq, 'yaxis')
    %colorbar;
    %axis([0 maxTime 0 75000]);
    %title('Right Hand Ciruclar Polarization');
    %saveas(1,summaryFileName);

Answer 1

我怀疑这个问题与spectrogram函数创建的图形有关。通过指定输出，您可以使用spectrogram函数来计算信号的短时傅里叶变换，然后创建绘图（请参见documentation）。在

计算转换后：

[S,F,T] = spectrogram(x,window,noverlap,F,fs)

至少有两种方法可以创建谱图图：surf，这是spectrogram和imagesc隐式使用的图。在第一种情况下，可以使用以下代码显示绘图（请参阅documentation）：

^{pr2}$

使用imagesc（参考this上一个答案和this注释）：

%plot the log spectrum
imagesc(T, F, log(S));

%flip the Y Axis so lower frequencies are at the bottom
set(gca, 'YDir', 'normal');