Why do I get "Array indices must be positive integers or logical values"

1 vue (au cours des 30 derniers jours)
Very new at matlab, i'm trying to fit linear function to a set of values. I keep getting "Array indices must be positive integers or logical values"
Please advise.
x = [62857 63320 63202 64754 64109 64298]'; % Population
y = [16366669 16864938 17087795 17224537 17301839 17095073]'; % Ridership
n = numel(y); % number of points being fitted
plot(x,y, '+')
A = [ones(6,1), x]; % design matrix
m = size(A,2); % parameters that we want fitted
b = A \ y;
f(x) = b(1) + b(2) *x;
xi = linspace(0,100);
fxi = f(xi);
plot(x, y, '+', xi, fxi)

Réponse acceptée

Mauro Fusco
Mauro Fusco le 25 Avr 2019
Arrays in Matlab are indexed starting from 1. Just replace xi = linspace(0,100); with
xi = linspace(1,100);
and it will not give error.
  2 commentaires
maria serey-roman
maria serey-roman le 25 Avr 2019
Thank you, that worked!
Walter Roberson
Walter Roberson le 25 Avr 2019
This deals with the problem accidentally, and does not solve the real issue.

Connectez-vous pour commenter.

Plus de réponses (1)

Walter Roberson
Walter Roberson le 25 Avr 2019
Modifié(e) : Walter Roberson le 25 Avr 2019
Also, your x range is about 60000, but the range over which you plot the projected line is 0 to 100.
plot(x, y, '+', x, polyval(flipud(b), x))

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by