'==' :no conversion from 'char *' to

'==' :no conversion from 'char *' to 英语翻译1.No conversion is issued without Conversion Recipes created prior to issuance2.No item is purchased without a correct Unit of Order.3.No filling Requisition has been kept for more than 24 hours in Issuing office. matlab里面Conversion to double from sym is not possible.怎么回事啊?求大神y=dsolve('D2y+y=sin(t) * cos(30)','t') plot(y)结果提示Conversion to double from sym is not possible. 这是怎么回事 求大神 what is conversion factors?什么是 CONVERSION FACTORS Conversion tracking是什么意思?conversion tracking是什么意思 full conversion是什么意思 conversion的定义 molar conversion什么意思 conversion ended是什么意思 conversion supplied是什么意思? after-conversion是什么意思 Conversion Kit 什么意思 beneficial conversion feature electric car conversion kit 英语翻译37No significant correlation (P>0.05) could be found between the levelof copper supply and the improvement in average daily body weightgain or the feed conversion. syms a x y x=sin(a) y=cosh(x) a=linspace(0,2*pi) plot(a,y) 错误在哪里?matlab中，错误提示：Conversion to double from sym is not possible matlab 函数 绘图失败a=vpa(zeros(1,P_N+1)); xx(i+1)=vpa(i/360); plot(xx,a,'-r') ;plot Conversion to double from sym is noConversion to double from sym is not possible .求指点 matlab中想求出y=dsolve('D2y+y=sin(t) * cos(30)','t'),再画图,该怎么办?会出现Conversion to double from sym is not possible.