我需要绘制一些麦克劳林级数,并且在图例上遇到了问题。
对于这两个方程-
x = (-1:.01:1);
% e^x
eqtn21 = 1;
eqtn22 = 1 + x;
eqtn23 = 1 + x + x.^2/2;
eqtn24 = 1 + x + x.^2/2 + x.^3/6;
eqtn25 = exp(x);
% cos(x)
eqtn31 = 1;
eqtn32 = 1 - x.^2/2;
eqtn33 = 1 - x.^2/2 + x.^4/24;
eqtn34 = 1 - x.^2/2 + x.^4/24 - x.^6/720;
eqtn35 = cos(x);
subplot(2,2,1)
plot(x,eqtn21,'r',x,eqtn22,'g',x,eqtn23,'b',x,eqtn24,'k',x,eqtn25,'c')
legend('First Term','First Two Terms','First Three Terms','First Four Terms','Exact Function')
subplot(2,2,2)
plot(x,eqtn31,'r',x,eqtn32,'g',x,eqtn33,'b',x,eqtn34,'k',x,eqtn35,'c')
legend('First Term','First Two Terms','First Three Terms','First Four Terms','Exact Function')
当我绘制它们时,图例出现了,但显示了5条红线,并且与图中的颜色不匹配。