c++ - Error when multiplying matrices with armadillo library (CodeBlocks) -

am trying multiply 2 small matrices cant code compile

#include <iostream> #include <armadillo>   using namespace std; using namespace arma;    int main() {   mat a1(1,2) ; a1.ones(); mat theta1(6,1); theta1.randn(); mat tool = trans(theta1); mat z1= tool*a1; //cout<<z1<<endl; cout<<theta1<<endl; } 

i following errors

||=== build: debug in tutorialpp (compiler: gnu gcc compiler) ===| obj\debug\main.o||in function zn4arma4blas4gemvideevpkcpkis5_pkt_s8_s5_s8_s5_s8_ps6_s5_':| d:\downloads\armadillo-7.200.1b\armadillo-7.200.1b\include\armadillo_bits\wrapper_blas.hpp|36|undefined reference towrapper_dgemv_'| obj\debug\main.o||in function zn4arma4blas4gemmideevpkcs3_pkis5_s5_pkt_s8_s5_s8_s5_s8_ps6_s5_':| d:\downloads\armadillo-7.200.1b\armadillo-7.200.1b\include\armadillo_bits\wrapper_blas.hpp|71|undefined reference towrapper_dgemm_'| ||error: ld returned 1 exit status| ||=== build failed: 3 error(s), 0 warning(s) (0 minute(s), 6 second(s)) ===|

please guide me can fix ,