Japan-to-China Post Fee
very shit matlab code of generating a Japan to China post fee picture
这里给出计算过后的四种运算方式的价格重量分段函数，资料来源日本邮政官网，希望我没算错。y 为价格（单位日元），x 为重量（单位千克）
草了为什么不支持分段函数显示，so sad
EMS
1400x+700 0.5 <= x < 1
1200x+900 1 <= x < 2
1000x+1300 2 <= x < 6
800x+2500 6 <= x <= 300
Air
700x+1350 0.5 <= x < 5
600x+1850 5 <= x < 10
400x+3850 10 <= x <= 30
SAL
600x+1200 1 <= x < 5
500x+1700 5 <= x < 10
300x+3700 10 <= x <= 30
船运
300x+1300 1 <= x < 10
250x+1800 10 <= x <= 30
直观看到起始的0 - 2 kg 特供版本
