rsquared计算确定系数(r2)从原始
数据(ydata)和模型不但数据(yestimation)。它还计算调整
系数(r2adj)考虑模型的参数的数量
(nparam)。

语法:
r2 = rsquared (ydata yestimation)
(r2, r2adj) = rsquared (ydata、yestimation nparam)

例子:
xdata = [1 5 14 23 25 48 49 59 73 77 99];
ydata = (-100 70 100 450 550 2200 2300 3400 5300 5906 9600];
情节(xdata ydata“ok”),等等
param_1 = polyfit (xdata ydata 1);
yestimation_1 = polyval (param_1 xdata);
[r2_1, r2adj_1] = rsquared (ydata yestimation_1,长度(param_1))
情节(xdata yestimation_1, - r)
param_2 = polyfit (xdata ydata 2);
yestimation_2 = polyval (param_2 xdata);
情节(xdata yestimation_2, - b)
[r2_2, r2adj_2] = rsquared (ydata yestimation_2,长度(param_2))
传奇({‘数据’,(r2 = ' num2str (r2_1)”,r2adj = '……
num2str (r2adj_1)], [' r2 = ' num2str (r2_2)”,r2adj = ' num2str (r2adj_2)]},…
“位置”,“最好”)

方程
ssr =总和((ydata-yestimation)。^ 2);%残差平方和
SStot =总和((ydata-mean (ydata))。^ 2);%总平方和
r2 = 1-SSres / SStot;%标准rsquared
r2adj = 1 - ssr / SStot *(长度(ydata) 1) / ((ydata) -nparam长度);%调整参数的数量

检查https://en.wikipedia.org/wiki/Coefficient_of_determination