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MATLAB for C/C++ Programmers

Support your C/C++ development using MATLAB’s prebuilt graphics functions and trusted numerics

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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

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Example C/C++ Application

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Example C/C++ Application

Wireless Networking Simulation

w3.antd.nist.gov/wctg/bluetooth/btint.html

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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

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Problems

Can’t easily visualize your data as plots, especially useful when developing and debugging

Difficult to verify your algorithm against a standard

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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

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Sending Data to MATLABfor Plotting and Testing

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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(…);

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Transferring Data to MATLAB// Data array in Cdouble data_c[10] = {8,1,2,3,2,5,-1,7,8,3};

// Array to store data ready to transfer to MATLABmxArray *data_ml;

// Data array in MATLAB formatdata_ml = mxCreateDoubleMatrix(1,10,mxREAL);

// Copy C array data into MATLAB array datamemcpy((char *)mxGetPr(data_ml),(char *)data_c,10*sizeof(double));

// Transfer to MATLAB

engPutVariable(ep,"data",data_ml);

S/W Demonstration (Sending_Data) after

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Test Your C/C++ Algorithms

Reconstruct algorithms in MATLAB Call test program to compare C result with M

resultengPutVariable(ep,“input”,input_ml);engPutVariable(ep,“output”,output_ml);engEvalString(ep,“testmyalg(input,output)");

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Example Algorithm Comparison C++ Code algorithmBits spread=addChips(diffOut[slice(i,1)]);

BitsIEEE802_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 algorithmTx_chips=reshape(Barker*Tx_symbols',[],1);Tx_samples(1:Samples_per_chip:end)=Tx_chips;

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Benefit of Sending Data to MATLAB

Easily visualize and understand your data Verify your algorithm is correct, reducing risk

of failure later

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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

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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

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Adding MATLAB Modules toYour C/C++ Application

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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

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Calling from C

S/W Demonstration after

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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

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Complete ApplicationDevelopment in MATLAB

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MATLAB Application Development

Build graphical user interface

Call C/C++ code The MATLAB Compiler• Standalone option

Benefits• Faster development

S/W Demonstration after

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Summary

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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