周波0.02秒采樣點128，頻率6400H在t = 0.055s時頻率降低20％在t = 0.14s時恢復，matlab如何編程圖中波形

搞得有點繁瑣，但還是畫出來了……?

f_sample?=?6400;?

T?=?0.02;

f_wave?=?1/T;

t?=?1?/?f_wave;

Point?=?f_sample?/?f_wave;%計算壹定采樣頻率下壹個周期的點數

P1?=?0.055?/?t?*?Point;

theta1?=?0.055?/?t?*?2?*?pi;

x?=?0:0.055/P1:0.055;

y?=?0:theta1/P1:theta1;

hold?on

f_wave?=?1?/?T?*?(1?-?0.2);?

t1?=?1?/?f_wave;

Point?=?f_sample?/?f_wave;

P2?=?(0.14?-?0.055)?/?t1?*?Point;

theta2?=?theta1?+?(0.14?-?0.055)?/?t1?*?2?*?pi;

x?=?0.055:(0.14-0.055)/P2:0.14;

y?=?theta1:(theta2-theta1)/P2:theta2;

hold?on

f_wave?=?1?/?T;?

t2?=?1?/?f_wave;

Point?=?f_sample?/?f_wave;

P3?=?(0.2?-?0.14)?/?t2?*?Point;

theta3?=?theta2?+?(0.2?-?0.14)?/?t2?*?2?*?pi;

x?=?0.14:(0.2-0.14)/P3:0.2;

y?=?theta2:(theta3-theta2)/P3:theta3;