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MATLABÌṩÁËÐí¶àº¯ÊýÓÃÓÚ²úÉú³£ÓõĻù±¾ÐźţºÈç½×Ô¾Ðźš¢Âö³åÐźš¢Ö¸ÊýÐźš¢ÕýÏÒÐźźÍÖÜÆÚ·½²¨µÈµÈ¡£ÕâЩÐźÅÊÇÐźŴ¦ÀíµÄ»ù´¡¡£ 1¡¢ ÀûÓÃMATLAB²úÉúÏÂÁÐÁ¬ÐøÐźŲ¢×÷ͼ¡£ £¨1£©x(t)??2u(t?1),?1?t?5 £¨2£©x(t)?e?0.3tsin(23t),0?t?30
£¨3£©x(t)?cos100t?cos3000t,?0.1?t?0.1
£¨4£©x(t)?cos(0.1?t)cos(0.8?t),0?t?200 ´ð£º£¨1£©¡¢
>> t=-1:0.02:5; >> x=(t>1);
>> plot(t,-2*x);
>> axis([-1,5,-3,1]);
>> title('Ñîæ¼æ¼ ÖìÒÕÐÇ'); >> xlabel('x(t)=-2u(t-1)');
£¨2£©¡¢
>> t=0:0.02:30;
>> x=exp(-0.3*t).*sin(2/3*t);
1
>> plot(t,x);
>> title('Ñîæ¼æ¼ ÖìÒÕÐÇ');
>> xlabel('x(t)=exp(-0.3*t).*sin(2/3*t)');
ÒòΪԺ¯ÊýÔÚt=15ºóx(t)ȡֵ½Ó½üÓÚÁ㣬ËùÒÔ½«ºá×ø±ê¸Ä³É0µ½15£¬¿´µÃ¸üÇåÎú
axis([0,15,-0.2,0.6]);
2
£¨3£©>> t=-0.1:0.01:0.1;x=cos(100*t)+cos(3000*t);plot(t,x);
>> title('Ñîæ¼æ¼ ÖìÒÕÐÇ');
>>xlabel('x=cos(100*t)+cos(3000*t)');
ÒòΪtµÄ¼ä¸ôȡ̫´ó£¬ÒÔÖÁÓÚº¯Êý²»¹»×¼È·£¬ËõСtµÄ¼ä¸ô£º t=-0.1:0.002:0.2;x=cos(100*t)+cos(3000*t); plot(t,x);title('Ñîæ¼æ¼')
>> t=-0.1:0.0001:0.1;
x=cos(100*t)+cos(3000*t);
>> plot(t,x);title('Ñîæ¼æ¼ ÖìÒÕÐÇ');
3
>> xlabel('x=cos(100*t)+cos(3000*t)');
£¨4£©¡¢t=0:0.01:200;
>> x=cos(0.1*pi*t).*cos(0.8*pi*t); >> plot(t,x);
>> title('Ñîæ¼æ¼ ÖìÒÕÐÇ');
>> xlabel('x=cos(0.1*pi*t).*cos(0.8*pi*t)');
ÒòΪΪÖÜÆÚº¯Êý£¬¿ÉÒÔ½«ºá×ø±êt¼ä¸ôÀ©´óÒÔ±ãÓÚ¹Û²ìͼÏñ >> axis([0,30,-1,1]);
4