z=15; syms t u(t) v(t) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN =8000; qin=20; qout =0; u1=diff(u); v1=diff(v); eq1 = Cin*u1==PN-(u-v)/R1; eq0 = Cin*u1==0-(u-v)/R1; eq2 = Cwall*v1==(u-v)/R1-(v-qout)/R2; eq3 = u(0)==20; eq4 = v(0)==z; [uSol1(t), vSol1(t)] = dsolve(eq1,eq2,eq3,eq4); [uSol2(t), vSol2(t)] = dsolve(eq0,eq2,eq3,eq4); figure(1) subplot(1,2,1),fplot(uSol1,[0 1440]); title('开启时室内温度') subplot(1,2,2),fplot( vSol1,[0 1440]); title('开启时墙体温度') figure(2) subplot(1,2,1),fplot(uSol2,[0 1440]); title('关闭时室内温度') subplot(1,2,2),fplot( vSol2,[0 1440]); title('关闭时墙体温度') ，将其中的z变为变量绘制三维图

给出matlab程序，其中R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v);

R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; % 定义常微分方程 syms u v eq1 = Cin*u == PN - (u - v)/R1; eq2 = Cwall*v == (u - v)/R1 - (v - qout)/R2; % ...

syms t u(t) v(t) z R1 = 1.2e-2; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -15; u1 = diff(u); v1 = diff(v); eq0 = Cinu1 == - (u - v)/R1; eq1 = Cinu1 == PN - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == qin; eq4 = v(0) == z; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4);中的dsolve改为ode45

R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -15; % 定义微分方程组 f1 = @(t, y) (PN - y(1) + y(2))/Cin/R1; f2 = @(t, y) ((y(1) - y(2))/R1 - (y(2) - qout)/R2)/Cwall; % ...

你可能改变了我的代码：syms t u(t) v(t) z R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v); eq1 = Cinu1 == PN - (u - v)/R1; eq0 = Cinu1 == 0 - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == 20; eq4 = v(0) == z; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4);

params = [Cin, Cwall, PN, qout, R1, R2, qin]; zSol = vpasolve(subs(eqs, vars, [uGrid(:), vGrid(:), zGrid(:)]), params); zSol = reshape(double(zSol.z), size(uGrid)); 这里使用ndgrid函数将u、v、z和t...

matlab中以三元一次常微分方程画三维图，比如这段代码：syms t u(t) v(t) z R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v); eq1 = Cinu1 == PN - (u - v)/R1; eq0 = Cinu1 == 0 - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == 20; eq4 = v(0) == z; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4);

可以使用Matlab的plot3函数将u、v和t作为三维坐标绘制成线条图。具体步骤如下： 1. 定义t的取值范围。 t = linspace(0, 100, 1000); 2. 计算u和v的值。 u1 = subs(uSol1, t); v1 = subs(vSol1, t); ...

按这个改一下我的MATLAB程序：R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; y=dsolve('D2y+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)D2y+1/R1/R2/Cin/Cwally=(R1+R2)/R2/Cwall*x+qout/Cwall/R2','x');

R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; ySol(x) = ...

syms y(x) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; a=diff(y); cond = [eqn(0)==0, a==0]; ySol(x) = dsolve(eqn, cond);报错

syms y(x) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2...

给代码：clear clc syms t u(t) v(t) z=15; R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v); eq0 = Cinu1 == 0 - (u - v)/R1; eq1 = Cinu1 == PN - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == 20; eq4 = v(0) == z; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4); figure(1) subplot(1, 2, 1), fplot(uSol1, [0 1440]); title('开启时室内温度'); xlabel('时间'), ylabel('温度') subplot(1, 2, 2), fplot(vSol1, [0 1440]); title('开启时墙体温度'); xlabel('时间'), ylabel('温度') figure(2) subplot(1, 2, 1), fplot(uSol2, [0 1440]); title('关闭时室内温度'); xlabel('时间'), ylabel('温度') subplot(1, 2, 2), fplot(vSol2, [0 1440]); title('关闭时墙体温度'); xlabel('时间'), ylabel('温度')加入稳态解u，v

syms t u(t) v(t) z = 15; R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u_ss = PN*R2/(R1+R2) + qout*R1/(R1+R2); v_ss = (PN*R2/(R1+R2) + z*R1/(R1+R2))*R1/...

clear clc syms t u(t) v(t) z=0; R1 = 1.2e-2; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -15; u1 = diff(u); v1 = diff(v); eq0 = Cinu1 == - (u - v)/R1; eq1 = Cinu1 == PN - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == qin; eq4 = v(0) == z; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4); figure(1) subplot(2,2,1),fplot(t,uSol1,[0 60]) xlabel('时间/min'),ylabel('开启时室内温度') subplot(2,2,2),fplot(t,vSol1,[0 60]) xlabel('时间/min'),ylabel('开启时室内温度') subplot(2,2,3),fplot(t,uSol2,[0 60]) xlabel('时间/min'),ylabel('开启时室内温度') subplot(2,2,4),fplot(t,vSol2,[0 60]) xlabel('时间/min'),ylabel('开启时室内温度')

R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -15; u = y(1); v = y(2); % 定义ODE方程 du_dt = y(3); dv_dt = y(4); dudt = Cin*du_dt + (u - v)/R1; dvdt = Cwall...

有没有问题：syms y(x) R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; ySol(x) =dsolve(eqn,'y(0)=0,Dy(0)=0','x');

R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; ...

修正代码：syms y(x) R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; cond1 = y(0)==0; % 添加初始条件 cond2 = diff(y)(0) == 0.5; ySol(x) = dsolve(eqn, [cond1, cond2]);

R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; cond1 = y(0)=...

syms A(t),B(t) C=10; cin = 1; P = 2; C=10; R1 = 1.210^-3; R2 = 9.210^-3; wall = 0; eqn='cinDB = P - (B(t) - A(t))R1'; cond='wall*DA = (B(t) - A(t))/R1 - (A(t) - C)/R2'; [B(t), A(t)] = dsolve(eqn, cond, 'B(0) = 5', 'A(0) = 0', t);

syms A(t) B(t) C(t) cin = 1; P = 2; R1 = 1.2*10^-3; R2 = 9.2*10^-3; wall = 0; eqn = cin * diff(B(t)) == P - (B(t) - A(t)) * R1; cond = wall * diff(A(t)) == (B(t) - A(t)) / R1 - (A(t) - C(t)) / R2; [B...

排版一下：syms t u(t) v(t) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN =8000; qin=20; qout =0; u1=diff(u); v1=diff(v); eq1 = Cinu1==PN-(u-v)/R1; eq0 = Cinu1==0-(u-v)/R1; eq2 = Cwall*v1==(u-v)/R1-(v-qout)/R2; eq3 = u(0)==20; eq4 = v(0)==z; [uSol1(t), vSol1(t)] = dsolve(eq1,eq2,eq3,eq4); [uSol2(t), vSol2(t)] = dsolve(eq0,eq2,eq3,eq4); figure(1) subplot(1,2,1),fplot3(uSol1,[0 1440],[0 30]); title('开启时室内温度') xlabel('时间'), ylabel('z轴'), zlabel('温度') subplot(1,2,2),fplot3(vSol1,[0 1440],[0 30]); title('开启时墙体温度') xlabel('时间'), ylabel('z轴'), zlabel('温度') figure(2) subplot(1,2,1),fplot3(uSol2,[0 1440],[0 30]); title('关闭时室内温度') xlabel('时间'), ylabel('z轴'), zlabel('温度') subplot(1,2,2),fplot3(vSol2,[0 1440],[0 30]); title('关闭时墙体温度') xlabel('时间'), ylabel('z轴'), zlabel('温度')

syms t u(t) v(t) z R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v); eq1 = Cin*u1 == PN - (u - v)/R1; eq0 = Cin*u1 == 0 - (u - v)...

syms y(x) R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; cond = y(0)==0; % 添加初始条件 cond1 = diff(y)(0)==0; % 添加初始条件 ySol(x) = dsolve(eqn, [cond, cond1]);这个代码错误: 文件: MAINONE.m 行: 10 列: 9 无效的数组索引。

R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; cond = y(0)==...

代码如下：clear clc syms t u(t) v(t) z R1 = 1.2e-2; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -20; u1 = diff(u); v1 = diff(v); eq0 = Cinu1 == - (u - v)/R1; eq1 = Cinu1 == PN - (u - v)/R1; eq2 = Cwall*v1 == (u - v)/R1 - (v - qout)/R2; eq3 = u(0) == z; eq4 = v(0) == z-5; [uSol1(t), vSol1(t)] = dsolve(eq1, eq2, eq3, eq4); [uSol2(t), vSol2(t)] = dsolve(eq0, eq2, eq3, eq4); figure(1) subplot(2,2,1),fsurf(t,z,uSol1,[0 1440 -25 20]) xlabel('时间/min'),ylabel('初始室内温度'),zlabel('开启时室内温度') subplot(2,2,2),fsurf(t,z,vSol1,[0 1440 -25 20]) xlabel('时间/min'),ylabel('初始室内温度'),zlabel('开启时墙体温度') subplot(2,2,3),fsurf(t,z,uSol2,[0 1440 -25 20]) xlabel('时间/min'),ylabel('初始室内温度'),zlabel('关闭时室内温度') subplot(2,2,4),fsurf(t,z,vSol2,[0 1440 -25 20]) xlabel('时间/min'),ylabel('初始室内温度'),zlabel('关闭时墙体温度')

R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = -20; % 定义微分方程 odefun = @(t,y) [Cin*(y(2) - y(1))/R1; (y(1) - y(2))/R1 - (y(2) - qout)/R2]; % 定义初始条件 y0 = [z; z...

R1=1.210^(-3);R2=9.210^(-3);cin=1.110^6;cwall=1.8610^8; diff_equ='cwallR1cinD2x+cwallDx=x/R1-(1/R1+1/R2)(cinR1Dx-8R1+x'; dsolve(diff_equ);

syms x(t) R1 R2 cin cwall diff_equ = cwall*R1*cin*diff(x,2) + cwall*diff(x) == x/R1 - (1/R1+1/R2)*(cin*R1*diff(x)-8*R1+x); xSol(t) = dsolve(diff_equ); 其中，syms 声明符号变量，diff_equ 定义...

% 定义常数 R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; % 定义常微分方程 syms u v eq1 = Cinu == PN - (u - v)/R1; eq2 = Cwallv == (u - v)/R1 - (v - qout)/R2; % 求解稳态解 u_steadystate = solve(eq1, u); v_steadystate = solve(eq2, v); % 求解u和v对时间的导数 u1 = diff(u); v1 = diff(v); % 定义时间t和初值条件 tspan = [0 1440]; y0 = [u_steadystate, v_steadystate]; % 定义ODE函数 odefun = @(t, y) [Cin(PN - (y(1) - y(2))/R1) - qin; ... Cwall((y(1) - y(2))/R1 - (y(2) - qout)/R2)]; % 求解ODE方程 [t, y] = ode45(odefun, tspan, y0); % 绘制u和v随时间变化的图像 figure; plot(t, y(:, 1), 'r-', t, y(:, 2), 'b--', 'LineWidth', 2); xlabel('Time (s)'); ylabel('Value'); legend('u', 'v'); title('u and v vs. Time');错误使用 odearguments 输入必须为单精度或双精度浮点值。出错 ode45 (第 107 行) odearguments(odeIsFuncHandle,odeTreatAsMFile, solver_name, ode, tspan, y0, options, varargin); 出错 MAINONE (第 39 行) [t, y] = ode45(odefun, tspan, y0);

这段代码的问题在于，在调用ode45函数求解ODE方程时，y0...这样就可以将符号变量u_steadystate和v_steadystate转换为数值变量，并且将它们组合成一个数值向量作为y0的值。这样就可以顺利地调用ode45函数求解ODE方程了。

相关推荐

syms T06.rar_matlab 正解_matlab程序-正解_机器人运动学

syms-t.rar_2FSK_2FSK相干解调_syms_相干信号

syms2elf-master_syms2elf_

给出matlab程序，其中R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6/60; Cwall = 1.86e8/60; PN = 8000; qin = 20; qout = 0; u1 = diff(u); v1 = diff(v);

按这个改一下我的MATLAB程序：R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; y=dsolve('D2y+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*D2y+1/R1/R2/Cin/Cwall*y=(R1+R2)/R2/Cwall*x+qout/Cwall/R2','x');

syms y(x) R1 = 1.2e-3; R2 = 9.2e-3; Cin = 1.1e6; Cwall = 1.86e8; PN = 8; qout = 0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; a=diff(y); cond = [eqn(0)==0, a==0]; ySol(x) = dsolve(eqn, cond);报错

有没有问题：syms y(x) R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)*diff(y,x,1)+1/R1/R2/Cin/Cwall*y==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; ySol(x) =dsolve(eqn,'y(0)=0,Dy(0)=0','x');

syms A(t),B(t) C=10; cin = 1; P = 2; C=10; R1 = 1.2*10^-3; R2 = 9.2*10^-3; wall = 0; eqn='cin*DB = P - (B(t) - A(t))*R1'; cond='wall*DA = (B(t) - A(t))/R1 - (A(t) - C)/R2'; [B(t), A(t)] = dsolve(eqn, cond, 'B(0) = 5', 'A(0) = 0', t);

R1=1.2*10^(-3);R2=9.2*10^(-3);cin=1.1*10^6;cwall=1.86*10^8; diff_equ='cwall*R1*cin*D2x+cwall*Dx=x/R1-(1/R1+1/R2)*(cin*R1*Dx-8*R1+x'; dsolve(diff_equ);

最新推荐

grpcio-1.63.0-cp38-cp38-linux_armv7l.whl

SQLyog-13.1.3-0.x86Community.exe

VB自动出题题库系统设计(源代码+系统).rar

zigbee-cluster-library-specification

管理建模和仿真的文件

MATLAB柱状图在信号处理中的应用：可视化信号特征和频谱分析

用Spring boot和vue写一个登录注册界面

JSBSim Reference Manual

"互动学习：行动中的多样性与论文攻读经历"

MATLAB柱状图在数据分析中的作用：从可视化到洞察

按这个改一下我的MATLAB程序：R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; y=dsolve('D2y+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)D2y+1/R1/R2/Cin/Cwally=(R1+R2)/R2/Cwall*x+qout/Cwall/R2','x');

有没有问题：syms y(x) R1=1.2e-3; R2=9.2e-3; Cin=1.1e6; Cwall=1.86e8; PN=8; qout=0; eqn = diff(y,x,2)+(1/R1/Cin+1/Cwall/Cin+1/R2/Cwall)diff(y,x,1)+1/R1/R2/Cin/Cwally==(R1+R2)/R2/Cwall*x+qout/Cwall/R2; ySol(x) =dsolve(eqn,'y(0)=0,Dy(0)=0','x');

syms A(t),B(t) C=10; cin = 1; P = 2; C=10; R1 = 1.210^-3; R2 = 9.210^-3; wall = 0; eqn='cinDB = P - (B(t) - A(t))R1'; cond='wall*DA = (B(t) - A(t))/R1 - (A(t) - C)/R2'; [B(t), A(t)] = dsolve(eqn, cond, 'B(0) = 5', 'A(0) = 0', t);

R1=1.210^(-3);R2=9.210^(-3);cin=1.110^6;cwall=1.8610^8; diff_equ='cwallR1cinD2x+cwallDx=x/R1-(1/R1+1/R2)(cinR1Dx-8R1+x'; dsolve(diff_equ);