t=['\partial(f_ip)/\partialt=-\Sigma_{i=1}^n\partial(f_ip)/'，...
   '\partialx_i + 0.5\Sigma_{i=1}^n\Sigma_{j=1}^n',...
   '\partial^2(b_{ij}p)/\partialx_i\partialx_j'];
gtext(t);
gtext('Y(\omega)=\int_0^\infty y(t)e^{-j\omegat}dt');
         
t=['\partial(f_ip)/\partialt=-\Sigma_{i=1}^n\partial(f_ip)/',...
   '\partialx_i + 0.5\Sigma_{i=1}^n\Sigma_{j=1}^n',...
   '\partial^2(b_{ij}p)/\partialx_i\partialx_j'];
tt=str2mat(t,'Y(\omega)=\int_0^\infty y(t)e^{-j\omegat}dt');
[x,y]=ginput(1); text(x,y,tt);
      
t=0:.1:2*pi; y=sin(t); plot(t,y) % 繪制正弦曲線
txt=['\displaystyle \frac{\partial f_i p}{\partial t}=',...
     '-\sum_{i=1}^n\frac{\partial f_i p}{\partial x_i} + ',...
     '0.5\sum_{i=1}^n\sum_{j=1}^n',...
     '\frac{\partial^2 b_{ij} p}{\partial x_i\partial x_j}'];
txt1='\displaystyle \mbox{添加中文} \int_0^\infty f(x)\mbox7t9vh3d t';
teximage_c(txt); teximage_c(txt1);