Question

matlab未定义函数或变量（附上源代码）

定义函数1：cal_Vfunction [ v,Z ] = cal_V( p,T,R,Tca,Pca,wa,Tc32,Pc32,w32,percent,liq )%计算方程中的常系数Tra = T/Tca;aa = 0.45724*R^2*(Tca)^2/(Pca)*(1+(0.37464+1.54226*wa-0.26992*wa^2)*(1-Tra^0.5))^2;ba = 0.07780*R*Tca/(Pca);Tr32 = T/Tc32;a32=0.45724*R^2*(Tc32)^2/(Pc32)*(1+(0.37464+1.54226*w32-0.26992*w32^2)*(1-Tr32^0.5))^2;b32 = 0.07780*R*Tc32/(Pc32);a = (1-percent)*(1-percent)*aa + 2*percent*(1-percent)*sqrt(aa*a32) + percent*percent*a32;b = (1-percent)*ba + percent*b32;%根据P-R方程算比体积f = p - R*T/(v-b)+a/(v*(v+b)+b*(v-b));v = solve(f);v = real(vpa(v,5));if(liq)v = vpa(min(v),5);Z = p*v/R/T;elsev = vpa(max(v),5);Z = p*v/R/T;end主程序：%R32相关参数Pc32 = 5.78e6;Tc32 = 351.26;w32 = 0.277;M32 = 52.02;Rg32 = 8314/M32;%R134a相关参数Pca = 4.05e6;Tca = 374.11;wa = 0.326;Ma = 102.03;Rga = 8314/Ma;T = 310;R = 8.314;for k = 1:21xR32 = 0+(k-1)*0.05;sigmaY = 2;p = 0.5e6;j = 0;while(abs(sigmaY)-1>0.001)yR32 = 0;[ vl,Zl ] = cal_V( p,T,R,Tca,Pca,wa,Tc32,Pc32,w32,xR32,1 );[ vv,Zv ] = cal_V( p,T,R,Tca,Pca,wa,Tc32,Pc32,w32,yR32,0 );[ Phial,Phi32l ] = cal_Phil( Zl,xR32,p,T,R,Tca,Pca,wa,Tc32,Pc32,w32 );[ Phiav,Phi32v ] = cal_Phiv( Zv,yR32,p,T,R,Tca,Pca,wa,Tc32,Pc32,w32 );k1 = Phial/Phiav;k2 = Phi32l/Phi32v;sigmaY(1) = k1*(1-xR32)+k2*xR32;i = 1;while 1yR32 = k2*xR32/sigmaY(i);[ Phiav,Phi32v ] = cal_Phiv( Zv,yR32,p,T,R,Tca,Pca,wa,Tc32,Pc32,w32 );k1 = Phial/Phiav;k2 = Phi32l/Phi32v;sigmaY(i+1) = k1*(1-xR32)+k2*xR32;if(abs(sigmaY(i+1)-sigmaY(i))<0.001)sigmaY = sigmaY(i+1);break;endi = i+1;endj = j+1;p = (0.5+j*0.01)*1000000;endresultP(k) = p;resultyR32(k) = yR32;endxR32 = 0:0.05:1;plot(xR32,resultP,'bo-',resultyR32,resultP,'k+-')title('T=310K,R32+R134a泡点压力与成分')xlabel('R320液(汽)相摩尔分数x(y)')ylabel('压力P(pa)')legend('R32x','R32y')运行后出现：未定义函数或变量 'cal_V'。并且在定义的第一个函数上中，有一个v，系统提示

Answer 1

子程序的v第一次出现之前确实没定义，你的v是在后面一句出现，运行到子程序肯定会报错的，当然这不是matlab给出的报错问题，matlab 给出的是没定义这个函数，你需要把这个函数拷贝到当前文件夹下或者把这个子程序文件加入到path中， matlab 才能识别出