2楼: Originally posted by 独孤神宇 at 2015-07-15 19:48:46
用cftool工具箱 拟合就是了 界面操作 简单快捷

4楼: Originally posted by dingd at 2015-07-16 09:30:25
考虑试试1stOpt，可以批量处理数据，关键是不需要初值，省事不少。

function [fitresult, gof] = createFit(x, y)

[xData, yData] = prepareCurveData( x, y );

% Set up fittype and options.
ft = fittype( 'a-b*exp(x)', 'independent', 'x', 'dependent', 'y' );
opts = fitoptions( 'Method', 'NonlinearLeastSquares' );
opts.Display = 'off';
% opts.StartPoint = [0.867276403277854 0.0574539084707549];

% Fit model to data.
[fitresult, gof] = fit( xData, yData, ft, opts );

% Create a figure for the plots.
figure( 'Name', 'untitled fit 1' );

% Plot fit with data.
subplot( 2, 1, 1 );
h = plot( fitresult, xData, yData );
legend( h, 'y vs. x', 'untitled fit 1', 'Location', 'NorthEast' );
% Label axes
xlabel x
ylabel y
grid on

% Plot residuals.
subplot( 2, 1, 2 );
h = plot( fitresult, xData, yData, 'residuals' );
legend( h, 'untitled fit 1 - residuals', 'Zero Line', 'Location', 'NorthEast' );
% Label axes
xlabel x
ylabel y
grid on

6楼: Originally posted by guo_zy_123 at 2015-07-16 10:40:33
function  = createFit(x, y)

= prepareCurveData( x, y );

% Set up fittype and options.
ft = fittype( 'a-b*exp(x)', 'independent', 'x', 'dependent', 'y' );
opts = fitoptions( 'Method', 'Nonlin ...

7楼: Originally posted by guo_zy_123 at 2015-07-16 10:43:51
忘了说了，公式写成了a-b*exp(x)...

5楼: Originally posted by 刘小嵩321 at 2015-07-16 09:47:40
matlab里面没有1stOpt...

8楼: Originally posted by 刘小嵩321 at 2015-07-16 11:29:42
我想把数据load（‘NM.dat')进去，然后把这个load的数据的第一列作为x轴，第一行作为y轴，应该如何做...