在MatlabControl中使用eval时出错 [英] Error using eval in matlabcontrol

问题描述

我使用 MatlabConrol 来连接Java和MATLAB.我想向MATLAB发送一个图像路径，以使用匹配的函数对其进行处理，并给我一些类似的图像和路径，以显示在Java GUI中.

I used MatlabConrol to connect Java and MATLAB. I want to send an image path to MATLAB to process it with matching functions and give me back a number of similar images and paths, to show in the Java GUI.

将图像路径传递给MATLAB时，我总是会遇到相同的错误:

I always get the same error when passing an image path to MATLAB:

Error using eval
Undefined function 'getinput' for input arguments of type 'char'.

这是我的MATLAB函数:

Here's my MATLAB function:

function matlab = getinput(input)
results = hgr(input);

还有我的Java代码:

And my Java code:

imag = ImageIO.read(fileChoose.getSelectedFile());
ImagePath = fileChoose.getSelectedFile().getAbsolutePath();

public void SendingMatlabControl() throws MatlabConnectionException,
  MatlabInvocationException {
  // create proxy
  MatlabProxy proxy;
  // Create a proxy, which we will use to control MATLAB
  MatlabProxyFactory factory = new MatlabProxyFactory();
  proxy = factory.getProxy();
  // Display 'hello world' like before, but this time using feval
    try {
      // call builtin function
      proxy.eval("getinput('imagepath')");
      // call user-defined function (must be on the path)
      proxy.eval("addpath('E:\\vm')");
      proxy.feval("matlab");
      proxy.eval("rmpath('E:\\vm)");
    } catch (MatlabInvocationException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    // Disconnect the proxy from MatLab
    proxy.disconnect();
  }

推荐答案

让我举一个调用函数，将其传递给输入并检索输出的示例.有两种方法:

Let me give an example of calling a function, passing it input, and retrieving the output. There are two ways, either:

• 使用 eval 并在MATLAB工作区中分配函数的结果，然后使用假设我们有一个MATLAB函数 myfunc.m ，该函数将字符串作为输入，并返回包含字符串，数字和向量的单元格数组:

  Suppose we had a MATLAB function myfunc.m that takes a string as input, and returns a cell array containing a string, a number, and a vector:

  function out = myfunc(str)
      out = cell(3,1);
      out{1} = sprintf('Welcome to %s!', str);
      out{2} = 99;
      out{3} = rand(10,1);
  end
  

  这是Java代码:

  import matlabcontrol.*;
  
  public class TestMyFunc
  {
      public static void main(String[] args)
          throws MatlabConnectionException, MatlabInvocationException
      {
          // create proxy
           MatlabProxyFactoryOptions options =
              new MatlabProxyFactoryOptions.Builder()
                  .setUsePreviouslyControlledSession(true).build();
          MatlabProxyFactory factory = new MatlabProxyFactory(options);
          MatlabProxy proxy = factory.getProxy();
  
          // call function and get output cell array
          String in = "Stack Overflow";
          Object[] out = proxy.returningFeval("myfunc", 1, in);
  
          // extract stuff from cell array
          out = (Object[]) out[0];
          String str = (String) out[0];
          double x = ((double[]) out[1])[0];
          double[] arr = (double[]) out[2];
  
          // show result
          System.out.println("str =\n " + str);
          System.out.println("x = \n " + x);
          System.out.println("arr =");
          for(int i=0; i < arr.length; i++) {
              System.out.println(" " + arr[i]);
          }
  
          // shutdown MATLAB
          //proxy.feval("quit");
  
          // close connection
          proxy.disconnect();
      }
  }
  

  我得到输出:

  str =
   Welcome to Stack Overflow!
  x =
   99.0
  arr =
   0.5974901918725793
   0.3353113307052461
   0.29922502333310663
   0.45259254156932405
   0.42264565322046244
   0.35960631797223563
   0.5583191998692971
   0.7425453657019391
   0.42433478362569066
   0.42935578857620504
  

  这篇关于在MatlabControl中使用eval时出错的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！