Power Law, Exponential and Logarithmic Fit软件

Finds and plots the linear fit to some data points when plotted on a log scale.

软件应用简介

logfit(X,Y,graphType), where X is a vector and Y is a vector or a 

matrix will plot the data with the axis scaling determined 

by graphType as follows: graphType-> xscale, yscale 

loglog-> log, log 

logx -> log, linear 

logy -> linear, log 

linear -> linear, linear 

A line is then fit to the scaled data in a least squares 

sense. 

See the ‘notes’ section below for help choosing a method. 

logfit(X,Y), will search through all the possible axis scalings and 

finish with the one that incurs the least error (with error 

measured as least squares on the linear-linear data.)

Notes: 

A power law relationship 

[slope, intercept] = logfit(x,y,’loglog’); 

yApprox = (10^intercept)*x.^(slope);

An exponential relationship 

[slope, intercept] = logfit(x,y,’logy’); 

yApprox = (10^intercept)*(10^slope).^x;

A logarithmic relationship 

[slope, intercept] = logfit(x,y,’logx’); 

yApprox = (intercept)+(slope)*log10(x);

A linear relationship 

[slope, intercept] = logfit(x,y,’linear’); 

yApprox = (intercept)+(slope)*x;

界面展示

结果示意

规格 价