Make error
When running make command, I get the following error and make fails, any advice would be great ++ -Wall -c reading.cpp -o reading.o reading.cpp:664:8: warning: unused variable 'c' [-Wunused-variable] int i,c,ii,j,k; ^ reading.cpp:664:10: warning: unused variable 'ii' [-Wunused-variable] int i,c,ii,j,k; ^ 2 warnings generated. c++ -Wall -c calc.cpp In file included from calc.cpp:19: ./calc.h:24:10: fatal error: 'gsl/gsl_machine.h' file not found #include <gsl/gsl_machine.h> ^~~~~~~~~~~~~~~~~~~ 1 error generated. make: *** [calc.o] Error 1