plot(x,y)
x 軸和y 軸均爲線性刻度
loglog(x,y)
x 軸和y 軸均爲對數刻度
semilogx(x,y)
semilogx(…) is the same as PLOT(…), except a logarithmic (base 10) scale is used for the X-axis.
x 軸爲對數刻度，y 軸爲線性刻度
semilogy(x,y)
semilogy(…) is the same as PLOT(…), except a logarithmic (base 10) scale is used for the Y-axis.
x 軸爲線性刻度，y 軸爲對數刻度