Error when compiling a code obtained from github

when I run a certain code that I downloaded from github, I'm faced with an error. The code is being compiled using mex. Can someone please explain to me what the error says and what I must do to fix it? I have provided the error below.

Error using mex
/usr/bin/ld: /usr/local/lib/librfftw.a(rplanner.o): relocation R_X86_64_32 against
`rfftw_config' can not be used when making a shared object; recompile with -fPIC
/usr/local/lib/librfftw.a: error adding symbols: Bad value
collect2: error: ld returned 1 exit status

Error in make (line 41)
mex('-O','./mexFMM3D.cpp',src1, src2,'-largeArrayDims',['-I',eigenDIR],['-I',fmmDIR],...

Error in example (line 11)
make(r,kernel,homogen,symmetry,outputfile);

Please let me know if you need more information. Also, I don't have a Computer Science (or significant coding experience)background. So, I would appreciate it if you can refrain from using Computer Science jargon when explaining what I must do to fix the problem.

[Jan]

Did you ask the author of this code already?

Posting the error message only does not allow to fix the code. Providing a link to the code would be required.