# showing error " Array indices must be positive or logical values"

2 vues (au cours des 30 derniers jours)
Prasannakumar reddy le 4 Avr 2024
Déplacé(e) : VBBV le 5 Avr 2024
clc
clear all
N=2;
c=linspace(0.035,0.010,21)
r=linspace(0.0001,1,21)
thetaroot=15;
thetatip=4;
a=5.7
R=0.35;
theta=(thetaroot+(r.*(thetatip-thetaroot)))./57.3
sigma=(N.*c(i))./(pi.*R)
lambda=sigma.*a((sqrt(1+32.*theta.*r)./(sigma(i).*a))-1)
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VBBV le 4 Avr 2024
Déplacé(e) : VBBV le 5 Avr 2024
i & j are complex quantities in Matlab, if you use it as index without assigning any value to them would give such error, since Matlab uses 1 based positive integer indexing
clc
clear all
N=2;
c=linspace(0.035,0.010,21);
r=linspace(0.0001,1,21);
thetaroot=15;
thetatip=4;
a=5.7;
R=0.35;
theta=(thetaroot+(r.*(thetatip-thetaroot)))./57.3;
sigma=(N.*c)./(pi.*R) % i & j are complex quantities in Matlab
sigma = 1x21
0.0637 0.0614 0.0591 0.0568 0.0546 0.0523 0.0500 0.0477 0.0455 0.0432 0.0409 0.0387 0.0364 0.0341 0.0318 0.0296 0.0273 0.0250 0.0227 0.0205 0.0182
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lambda=sigma.*a((sqrt(1+32.*theta.*r)./(sigma.*a))-1) % same in this line
Array indices must be positive integers or logical values.

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### Réponses (2)

Torsten le 4 Avr 2024
Modifié(e) : Torsten le 4 Avr 2024
lambda=sigma.*a.*((sqrt(1+32.*theta.*r)./(sigma(i).*a))-1)
lambda=sigma.*a((sqrt(1+32.*theta.*r)./(sigma(i).*a))-1)
And since "i" is undefined, c(i) and thus sigma(i) are empty.
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Prasannakumar reddy le 4 Avr 2024
thanks it's working.
Image Analyst le 4 Avr 2024
If this Answer solves your original question, then could you please click the "Accept this answer" link to award the answerer with "reputation points" for their efforts in helping you? They'd appreciate it. Thanks in advance. 🙂 Note: you can only accept one answer (so pick the best one) but you can click the "Vote" icon for as many Answers as you want. Voting for an answer will also award reputation points.

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Image Analyst le 4 Avr 2024
Déplacé(e) : VBBV le 5 Avr 2024
See the FAQ for a thorough discussion of the error:
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