matlab里预测函数怎么编程

时间:2025-01-25 20:19:31 网络游戏

在MATLAB中,可以使用多种方法进行预测编程。以下是一些常见的方法和示例代码:

1. 使用MATLAB自带的神经网络工具箱

```matlab

% 加载数据

p = load('shuru.txt');

t = load('shuchu.txt');

% 数据归一化

[pn, minp, maxp, tn, mint, maxt] = premnmx(p, t);

% BP网络训练

net = newff([-1, 1], [5, 1], {'tansig', 'tansig', 'purelin'}, 'traingdx');

net.trainParam.show = 1000;

net.trainParam.Lr = 0.05;

net.trainParam.epochs = 3000;

net.trainParam.goal = 1e-5;

net = train(net, pn, tn);

% 对原数据进行仿真

an = sim(net, pn);

```

2. 灰色预测函数

```matlab

function yc = gm(x0, m)

n = length(x0);

x1 = zeros(1, n);

x1(1) = x0(1);

for i = 2:n

x1(i) = x1(i-1) + x0(i);

end

i = 2:n;

y = zeros(1, n);

y(i-1) = x0(i);

for i = 1:n-1

y(i+1) = y(i) + x0(i);

end

B = [-0.5*(x1(i)+x1(i+1)), ones(n-1,1)];

au = inv(B*B)*B*y;

for i = 1:n+1+m

ago(i) = (x0(1)-au(2)/au(1))*exp(-au(1)*(i-1)) + au(2)/au(1);

end

yc(1) = ago(1);

for i = 1:n-1

yc(i+1) = ago(i+1) - ago(i);

end

end

```

3. 粒子群算法优化BP神经网络预测

```matlab

% 读取数据

data = xlsread('data.xlsx', 'Sheet1', 'A1:N252');

input = data(:, 1:end-1);

output = data(:, end);

% 划分训练集和测试集

% 归一化

% 确定BP神经网络的隐含层最优节点数量

% 使用粒子群算法优化BP的神经网络权重和阈值

% 利用优化后的参数训练BP神经网络

% 计算BP和PSO-BP的测试集预测误差

```

4. 状态空间模型和MPC控制器

```matlab

% 创建一个简单的状态空间模型

A = [1 1; 0 1];

B = [0.5; 1];

C = [1 0];

D = 0;

sys = ss(A, B, C, D);

% 构建MPC控制器

mpcobj = mpc(sys);

mpcobj.PredictionHorizon = 10;

mpcobj.ControlHorizon = 3;

% 设置输入输出约束

mpcobj.MV.Min = -2;

mpcobj.MV.Max = 2;

mpcobj.OV.Min = -1;

mpcobj.OV.Max = 1;

% 设置权重

mpcobj.Weights.MV = 0.1;

mpcobj.Weights.MVRate = 0.1;

mpcobj.Weights.OV = 1;

% 仿真跑起来

t = 0:50;

r = 0.5*square(0.1*t);

[y, t, u] = sim(mpcobj, 51, r);

```

5. 使用拟合工具箱