Calculating Mean Square Error

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Maria 2014-4-19

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https://ww2.mathworks.cn/matlabcentral/answers/126373-calculating-mean-square-error

评论： Image Analyst 2017-2-28

采纳的回答： Image Analyst

What will be the code of the function for calculating Mean Square Error

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Christy Lentz 2017-2-27

What happens when the returned value is NaN? I'm using 2 arrays of observational measurements and then simulation measurements and trying to find the MSE, but upon using this algorithm I get a NaN back.

Image Analyst 2017-2-28

What do you want to do when there's a nan. You know there is a 'omitnans' option to mean() don't you?

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Answer 1

Image Analyst 2014-4-20

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在 MATLAB Online 中打开

OK so we know the desired signal, at least you could if you made up the equation for it. But what is the actual signal? Do you have that in some array, perhaps that you read in from some kind of position sensor or image analysis? To calculate MSE you need to have two signals - the desired/true signal, and your actual/test signal. Then just do

MSE = mean((desired - mean).^2);

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Image Analyst 2014-4-20

在 MATLAB Online 中打开

OK, looks like you need a full blown demo.

% Demo to plot a point's height as it revolves around a circle.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 22;
xCenter = 12;
yCenter = 10;
% Make a timeline of 40 seconds with samples every 0.01 second.
t = 0 : 0.01 : 40;
% Let's say that there is 8 revolutions in that time.
numberOfRevolutions = 8;
% Produce the angles.  They will go from 0 to numberOfRevolutions * 2*pi.
theta = linspace(0, numberOfRevolutions * 2 * pi, length(t));
radius = 5;
x = radius * cos(theta) + xCenter;
y = radius * sin(theta) + yCenter;
subplot(1,2,1);
plot(x, y, 'LineWidth', 3);
axis square;
xlim([0 20]);
ylim([0 20]);
grid on;
title('The circlular path it revolves around', 'FontSize', fontSize);
xlabel('X', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);
% m = -40;
% velocity = 0.25;
% ft = t;
% azimuth = 2 * 3.14 * ft/m;
% Plot azimuth (the y coordinate) as a function of time.
subplot(1,2,2);
plot(t, y, 'b-', 'LineWidth', 3);
grid on;
ylim([0, yCenter+radius]);
title('Height of a point as it revolves around', 'FontSize', fontSize);
xlabel('time', 'FontSize', fontSize);
ylabel('Y, or Azimuth', 'FontSize', fontSize);
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);