GCC= gcc 
PROG= correlation

${PROG} :       ${PROG}.o step.o fluke.o flukem.o
                ${GCC} -O ${PROG}.o step.o fluke.o flukem.o -o ${PROG}

${PROG}.o:      ${PROG}.c
                ${GCC} -c ${PROG}.c

step.o :        step.c
                ${GCC} -c -O step.c

fluke.o:        fluke.c
                gcc -c fluke.c

flukem.o:       flukem.c
                gcc -c flukem.c