1. © 2004 The MathWorks, Inc. 1 MATLAB for C/C++ Programmers Support your C/C++ development using MATLAB’s prebuilt graphics functions and trusted numerics

2. © 2004 The MathWorks, Inc. 2 Agenda  Example C/C++ application  Sending data to MATLAB for plotting and testing  Adding MATLAB S/W modules into your application  Complete application development in MATLAB

3. © 2004 The MathWorks, Inc. 3 Example C/C++ Application

4. © 2004 The MathWorks, Inc. 4 Example C/C++ Application  Wireless Networking Simulation  w3.antd.nist.gov/wctg/b luetooth/btint.html

5. © 2004 The MathWorks, Inc. 5 C/C++ Code and Development  Code Files Classes  Development Build and run Debug  Difficult to understand data and operation of algorithms S/W (C_Application) Demonstration after

6. © 2004 The MathWorks, Inc. 6 Problems  Can’t easily visualize your data as plots, especially useful when developing and debugging  Difficult to verify your algorithm against a standard

7. © 2004 The MathWorks, Inc. 7 Solution: Send Data to MATLAB  High-level interpreted language and development environment  More than1000 built-in functions  Graphics and charting  Linear algebra, statistics, transforms, filtering  Can control from another application

8. © 2004 The MathWorks, Inc. 8 Sending Data to MATLAB for Plotting and Testing

9. © 2004 The MathWorks, Inc. 9 Calling MATLAB from C/C++  Start MATLAB matlab.exe /Automation Optionally start desktop  In C/C++ code Use MATLAB Engine library #include “engine.h” Engine *ep; ep = engOpen(NULL); engPutVariable(…); engGetVariable(…); engEvalString(…);

10. © 2004 The MathWorks, Inc. 10 Transferring Data to MATLAB // Data array in C double data_c[10] = {8,1,2,3,2,5,-1,7,8,3}; // Array to store data ready to transfer to MATLAB mxArray *data_ml; // Data array in MATLAB format data_ml = mxCreateDoubleMatrix(1,10,mxREAL); // Copy C array data into MATLAB array data memcpy((char *)mxGetPr(data_ml),(char *)data_c,10*sizeof(double)); // Transfer to MATLAB engPutVariable(ep,"data",data_ml); S/W Demonstration (Sending_Data) after

11. © 2004 The MathWorks, Inc. 11 Data Analysis and Visualization  Data from C/C++ application now exits in MATLAB workspace  View in array editor  Plot with 100s functions  Command line of interactive  Statistics and fitting Not shown, Demo instead

12. © 2004 The MathWorks, Inc. 12 Sending Commands to MATLAB  Simple plot example engEvalString(ep, “stem(data);");  Animation example Complex data structure Transfer to MATLAB data structure Not shown, Demo instead

13. © 2004 The MathWorks, Inc. 13 Test Your C/C++ Algorithms  Reconstruct algorithms in MATLAB  Call test program to compare C result with M result engPutVariable(ep,“input”,input_ml); engPutVariable(ep,“output”,output_ml); engEvalString(ep,“testmyalg(input,output)");

14. © 2004 The MathWorks, Inc. 14 Example Algorithm Comparison  C++ Code algorithm Bits spread=addChips(diffOut[slice(i,1)]); Bits IEEE802_11b_Transmitter::addChips(const Bits& input) { Bits spreadOut(input.size()*Ns,false); for (int i=0;i<input.size();++i){ for(int j=0; j<11; ++j) { spreadOut[i*Ns+4*j]= m_chip[j]^input[i]; } return spreadOut; }  M Code algorithm Tx_chips=reshape(Barker*Tx_symbols',[],1); Tx_samples(1:Samples_per_chip:end)=Tx_chips;

15. © 2004 The MathWorks, Inc. 15 Benefit of Sending Data to MATLAB  Easily visualize and understand your data  Verify your algorithm is correct, reducing risk of failure later

16. © 2004 The MathWorks, Inc. 16 Problems  No canned math, statistics, numerics and data analysis functions common in technical computing algorithms  You must write them yourself, which can be time consuming, or use other libraries

17. © 2004 The MathWorks, Inc. 17 Solution: MATLAB Module for Engineering or Mathematical Components  For heavy engineering or mathematical components of your application  Create a MATLAB module using the many built-in functions Vector and matrix based Application specific functions in toolboxes  Convert to a DLL or COM object with the MATLAB compiler Distribute freely with your application

18. © 2004 The MathWorks, Inc. 18 Adding MATLAB Modules to Your C/C++ Application

19. © 2004 The MathWorks, Inc. 19 Build Component Example  Design M code function foo.m  Use MATLAB Compiler Converts MATLAB Code to standalone exe or library Create Foolib.dll  Add include and library files to project  See application note 27671

20. © 2004 The MathWorks, Inc. 20 Calling from C S/W Demonstration after

21. © 2004 The MathWorks, Inc. 21 Benefits of Using a MATLAB Module  Leave MATLAB to the heavy math and engineering tasks what it is designed for  No need to spend time re-creating functions in C/C++ yourself that are already available in MATLAB  No need to test MATLAB’s trusted numerics

22. © 2004 The MathWorks, Inc. 22 Complete Application Development in MATLAB

23. © 2004 The MathWorks, Inc. 23 MATLAB Application Development  Build graphical user interface  Call C/C++ code  The MATLAB Compiler Standalone option  Benefits Faster development S/W Demonstration after

24. © 2004 The MathWorks, Inc. 24 Summary

25. © 2004 The MathWorks, Inc. 25 MATLAB Can Support Your C/C++ Development  Send data to MATLAB for plotting and testing Easily visualize and understand your data Verify your algorithm is correct  Add MATLAB S/W modules into your application Leave MATLAB to the heavy math and engineering No need to spend time re-creating functions in C/C++  Develop complete applications in MATLAB Faster development technical computing problems