Problem with transposition with Armadillo Library

[lasert]

Dear people,

I am programming a Kalman Filter and i decided to use the Armadillo library for linear algebra.
I have troubles with Matrix transposition. I can compute the transposition,
but when I want to use the result for another operation (ex: multiplication)
I can't event compile my project (I use a makefile).

Please see the code below :

The main.cpp

 
#include <iostream>
#include "Quaternion.h" 

using namespace std;
using namespace arma;

int main(int argCount, char **argValue) {

 fmat33 B ;
  B << 1 << 2<< 3<<endr
    << 4 << 5<< 6<<endr
    << 1 << 2<< 8<<endr;

  B.print("B vaut ;");
  
  fmat C = trans(B);
  C.print("C :"); 
  fmat D = C*B;  
//  D.print("D : ");
 return 0;
}

When I comment the line fmat D = C*B , I can compile the project.
See what happens when I comment the line:

es/NavMultiCap_Armadillo/bin$ make
[ 14%] Building CXX object CMakeFiles/NavMultiCap.dir/src/Kalman.cpp.o
[ 28%] Building CXX object CMakeFiles/NavMultiCap.dir/src/main.cpp.o
[ 42%] Building CXX object CMakeFiles/NavMultiCap.dir/src/MeasureStorage.cpp.o
[ 57%] Building CXX object CMakeFiles/NavMultiCap.dir/src/Quaternion.cpp.o
[ 71%] Building CXX object CMakeFiles/NavMultiCap.dir/src/Sensor.cpp.o
[ 85%] Building CXX object CMakeFiles/NavMultiCap.dir/src/StateModel.cpp.o
[100%] Building CXX object CMakeFiles/NavMultiCap.dir/src/StateVector.cpp.o
Linking CXX executable NavMultiCap
[100%] Built target NavMultiCap
emin3m@emin3m-laptop:/media/347C31257C30E2F2/Base/Codes_CMD/Kalman_Fusion/branches/NavMultiCap_Armadillo/bin$ 

But if I uncomment it I have this error from the shell :

/NavMultiCap_Armadillo/bin$ make
Scanning dependencies of target NavMultiCap
[ 14%] Building CXX object CMakeFiles/NavMultiCap.dir/src/main.cpp.o
Linking CXX executable NavMultiCap
CMakeFiles/NavMultiCap.dir/src/main.cpp.o: In function `void arma::atlas::cblas_gemv<float>(CBLAS_ORDER, CBLAS_TRANSPOSE, int, int, float, float const*, int, float const*, int, float, float*, int)':
main.cpp:(.text._ZN4arma5atlas10cblas_gemvIfEEv11CBLAS_ORDER15CBLAS_TRANSPOSEiiT_PKS4_iS6_iS4_PS4_i[void arma::atlas::cblas_gemv<float>(CBLAS_ORDER, CBLAS_TRANSPOSE, int, int, float, float const*, int, float const*, int, float, float*, int)]+0x6f): undefined reference to `wrapper_cblas_sgemv'
CMakeFiles/NavMultiCap.dir/src/main.cpp.o: In function `void arma::atlas::cblas_gemm<float>(CBLAS_ORDER, CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, int, int, int, float, float const*, int, float const*, int, float, float*, int)':
main.cpp:(.text._ZN4arma5atlas10cblas_gemmIfEEv11CBLAS_ORDER15CBLAS_TRANSPOSES3_iiiT_PKS4_iS6_iS4_PS4_i[void arma::atlas::cblas_gemm<float>(CBLAS_ORDER, CBLAS_TRANSPOSE, CBLAS_TRANSPOSE, int, int, int, float, float const*, int, float const*, int, float, float*, int)]+0x7d): undefined reference to `wrapper_cblas_sgemm'
collect2: ld returned 1 exit status
make[2]: *** [NavMultiCap] Erreur 1
make[1]: *** [CMakeFiles/NavMultiCap.dir/all] Erreur 2
make: *** [all] Erreur 2

Could you help me to solve this problem ?
I was using the library Eigen before and everything was
fine, until my colleagues "forced" my to use Armadillo...
for better compatibility.

Thank you

[JLBorges]

An undefined reference of this kind means that a required library is not being searched.

Are you missing an -larmadillo compiler/linker option?

[lasert]

Hello,

Yes it was a problem concerning linking to Lapack and BLAS. My compiled Armadillo library was not the folder "/usr/" so I had problem of dependencies wih the Lapack and blas.

Solution : I added the compiled armadillo library to the folder "/usr/" and I also added the following line to my CMakeList.txt file:
set(Armadillo_DIR "/usr/share/Armadillo/CMake/")

So my CMakeLists.txt finally looks like :

# Ajustez en fonction de votre version de CMake
cmake_minimum_required (VERSION 2.8)

# Nom du projet
project (NavMultiCap)

set(Armadillo_DIR "/usr/share/Armadillo/CMake/") 
find_package (Armadillo REQUIRED)

include_directories(${ARMADILLO_INCLUDE_DIR})

#Configuration de l'exécutable
file(
        GLOB_RECURSE
        source_files
        src/*
)

add_executable(
	NavMultiCap
	 ${source_files}
)

# Hello sera linké avec les bibliothèques d'OpenCV

target_link_libraries (NavMultiCap ${Armadillo_LIBS}) */

Now everything works perfectly.