使用 tcpip 与 matlab 连接实时绘制数据

Question

我用 tcpip 函数连接我的 iPhone 和 matlab。

我需要实时绘制数据（在对数据进行一些计算之前）。 我使用了在互联网上找到的real_time_data_stream_plotting.m。

%% Real Time Data Stream Plotting Example
function real_time_data_stream_plotting
%%
% This example demonstrates how to automatically read a set number of data bytes as and
% when they are available. This MATLAB(R) script also generates a real time plot of streaming 
% data collected from the TCPIP server.  
%
% The script may be updated to use any instrument/device/TCPIP server
% to collect real time data. You may need to update the IP address and
% port.
%
% To generate a report of this entire script, you may use the PUBLISH
% command at the MATLAB(R) command line as follows: 
% 
% publish(real_time_data_plot);

% Author: Ankit Desai
% Copyright 2010 - The MathWorks, Inc.

%% Create the interface object
% Create a TCPIP object listening to port 19 (Character Generator).
%
% *Note* : To enable character generator service at port 19 on a Windows platform, enable:
%
%  Control Panel > Add Remove Programs > Add/Remove Windows Component > Networking Services
%
interfaceObject = tcpip('192.168.1.111',52928);

%% 
% Setup a figure window and define a callback function for close operation
figureHandle = figure('NumberTitle','off',...
    'Name','Live Data Stream Plot',...
    'Color',[0 0 0],...
    'CloseRequestFcn',{@localCloseFigure,interfaceObject});

%%
% Setup the axes 
axesHandle = axes('Parent',figureHandle,...
    'YGrid','on',...
    'YColor',[0.9725 0.9725 0.9725],...
    'XGrid','on',...
    'XColor',[0.9725 0.9725 0.9725],...
    'Color',[0 0 0]);

xlabel(axesHandle,'Number of Samples');
ylabel(axesHandle,'Value');

%%
% Initialize the plot and hold the settings on
hold on;
plotHandle = plot(axesHandle,4,'-y','LineWidth',1);

%% Setup interface object to read chunks of data
% Set the number of bytes to read at a time
bytesToRead = 500;

%%
% Define a callback function to be executed when desired number of bytes
% are available in the input buffer
interfaceObject.BytesAvailableFcn = {@localReadAndPlot,plotHandle,bytesToRead};
interfaceObject.BytesAvailableFcnMode = 'byte';
interfaceObject.BytesAvailableFcnCount = bytesToRead;

%% 
% Open the interface object
fopen(interfaceObject);
pause(3);
snapnow;
%% Implement the bytes available callback
function localReadAndPlot(interfaceObject,~,figureHandle,bytesToRead)

%% 
% Read the desired number of data bytes
data = fread(interfaceObject,bytesToRead);

%% 
% Update the plot
set(figureHandle,'Ydata',data);

%% Implement the close figure callback
function localCloseFigure(figureHandle,~,interfaceObject)

%% 
% Clean up the interface object
fclose(interfaceObject);
delete(interfaceObject);
clear interfaceObject;

%% 
% Close the figure window
delete(figureHandle);

我的问题是我有一个实时绘图，但我不知道我正在绘制哪些数据。我知道从 iPhone 传来的数据是一个 62 列的矩阵（如果我直接从 iPhone 导出数据，我会得到一个 62 列的 .csv 文件）。

如何选择我绘制的列？

非常感谢！

Answer 1

以下是我对仅为所需列的数据编制索引的看法：

function real_time_data_stream_plotting()

        % These can be very well arguments for the function
        FRAME_SIZE  = 62;     % This many columns (each columns is one byte)
        FRAME_COUNT = 500;    % This much data to plot at once
        DATA_COLUMN = 3       % Position of the plotted column

        % Create connection
        conn = tcpip('192.168.1.111', 52928);

        % Set-up graphics
        hf = figure( ...
           'NumberTitle',     'off', ...
           'Name',            'Live Data Stream Plot', ...
           'Color',           [0 0 0], ...
           'CloseRequestFcn', {@localCloseFigure,conn} ...
        );

        ha = axes( ...
           'Parent', hf,...
           'YGrid',  'on', ...
           'YColor', [0.9725 0.9725 0.9725], ...
           'XGrid',  'on', ...
           'XColor', [0.9725 0.9725 0.9725], ...
           'Color',  [0 0 0] ...
        );
        hold(ha, 'on');
        xlabel(ha,'Number of Samples');
        ylabel(ha,'Value');

        hl = plot(ha, 4, '-r', 'LineWidth', 1);

        % Set-up connection callback
        conn.BytesAvailableFcn      = {@update_plot, hl, FRAME_SIZE, FRAME_COUNT, DATA_COLUMN};
        conn.BytesAvailableFcnMode  = 'byte';
        conn.BytesAvailableFcnCount = FRAME_SIZE * FRAME_COUNT;

        % Open connection and exit
        fopen(conn);
        pause(3);
        snapnow;

end


% -------- Local Functions --------

function update_plot(conn, ~, hl, frame_size, frame_count, data_column)

        data = fread(conn, frame_count*frame_size);
        data = data(data_column + frame_size*(0:frame_count-1));
        set(hl, 'YData', data);

end


function clean_up_on_close(hf, ~, conn)

        fclose(conn);
        delete(conn);
        clear conn;
        delete(hf);

end

但是，我不愿意发布基于受版权保护作品的代码...