mm set as the contraction reference pitch p ng accordingly the answer in step s3 becomes yes and in step s4 the needle location data representing the point q 9 is stored as a proper or adoptable contraction stitch pattern data into the edit data memory 68 in the next step s5 it is determined whether the needle location data representing the point q 9 stored into the edit data memory 68 is a final needle location data since the needle location data representing the point q 9 is not the final needle location data the answer in step s5 becomes no and the step s1 and the subsequent steps are executed that is the same processing as described above is carried out for the combination of the needle location data between the point q 9 and each of the subsequent points q 10 and so on since the answer in step s3 for the combination between the point q 9 and a point q 18 becomes yes the needle location data representing the point q 18 is stored as a proper or adoptable contraction stitch pattern data into the edit data memory 68 then the determination of step s3 is carried out for the combination between the point q 18 and a point q 19 and subsequently for the combination between the point q 18 and a point q 20 the answer in step s3 for both the combinations becomes no since the needle location.