matlab分段拟合程序,如何在Matlab中通过一系列分段线拟合曲线？

首先,您的问题不称为曲线拟合.曲线拟合就是在您拥有数据时,从某种意义上说,您可以找到描述它的最佳函数.另一方面,您希望创建函数的分段线性逼近.

我建议采取以下策略：

>手动拆分为部分.截面尺寸应取决于导数,大导数 – >小节

>在节之间的节点处对函数进行采样

>找到通过上述点的线性插值.

以下是执行此操作的代码示例.您可以看到红线(插值)非常接近原始函数,尽管部分数量很少.这是由于自适应部分大小而发生的.

function fitLogLog()

x = 2:1000;

y = log(log(x));

%# Find section sizes, by using an inverse of the approximation of the derivative

numOfSections = 20;

indexes = round(linspace(1,numel(y),numOfSections));

derivativeApprox = diff(y(indexes));

inverseDerivative = 1./derivativeApprox;

weightOfSection = inverseDerivative/sum(inverseDerivative);

totalRange = max(x(:))-min(x(:));

sectionSize = weightOfSection.* totalRange;

%# The relevant nodes

xNodes = x(1) + [ 0 cumsum(sectionSize)];

yNodes = log(log(xNodes));

figure;plot(x,y);

hold on;

plot (xNodes,yNodes,'r');

scatter (xNodes,yNodes,'r');

legend('log(log(x))','adaptive linear interpolation');

end