Index exceeds number of array elements (1)?

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Riley Vargas
Riley Vargas 2018 年 11 月 6 日
コメント済み: Mark Linne 2021 年 7 月 30 日
dt = 0.005; N = 200; %(s)
P3s = 2; P3d = 23.5; %(mmHg)
V2(1) = .475; %(L)
V0 = .06; %(L)
C2 = 0.05; %(L/mmHg)
R1 = 30; R2 = 30; %(mmHg*s/L)
P1 = 11; %(mmHg)
P3(1:120) = P3s;
P3(121:200) = P3d;
t = 0:dt:(N-1)*dt;
plot(t, P3)
xlabel('Time (s)'), ylabel('Pressure (mmHg)')
for i = 1:N
P2(i) = (V2(i) - V0) / C2;
if P2(i) > P3(i); Q3(i) = (P2(i) - P3(i)) / R2;
else Q3(i) = 0;
end
Q1(i) = (P1 - P2(i)) / R1;
Q2(i) = Q1(i) - Q3(i);
P2(i+1) = P2(i) + Q2(i)*dt;
end
tp = 0:dt:N*dt;
figure
plot(tp, P2)
xlabel('Time (s)'), ylabel('P2 (mmHg)')
Error is in line 12 " P2(i) = (V2(i) - V0) / C2;"
What is strange about this problem is that the code runs perfectly on my computer, but when transferred to another and ran, it gives the error message. Any ideas?
  1 件のコメント
Mark Linne
Mark Linne 2021 年 7 月 30 日
I have two nested loops:
for i=1:1:NJ
for f=1:1:NJ
Later in the script I need to do a for loop using:
for L=abs(i-f):1:(i+f)
For obvious reasons, the (i+f) generates the error under discussion. Is there a known way to work around this issue (written by a dinosaur who learned Fortran in 1970, still thinks that way, and would prefer to be able to set array sizes myself at the start of the code)?

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採用された回答

Aquatris
Aquatris 2018 年 11 月 6 日
編集済み: Aquatris 2018 年 11 月 6 日
You only define V2(1) in your code and do not increase the size of the V2 variable. So I think you are missing a code in your for loop which assigns values to V2(i+1).
It probably runs in your computer because your workspace includes a V2 variable with correct size from another script so the code does not yell at you.
  4 件のコメント
Aquatris
Aquatris 2019 年 3 月 13 日
In his code he never defined V2(2) so he added a line in his for loop, something like;
for i = 1:N
...
V2(i+1) = *equation*
end

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その他の回答 (7 件)

sura naji
sura naji 2020 年 2 月 18 日
clc
clear
close all
% Problem Statement
Npar = 17;
VarLow=0.1;
VarHigh = 35;
%BBBC parameters
N=50; %number of candidates
MaxIter=100; %number of iterations
% initialize a random value as best value
XBest = rand(1,Npar).* (VarHigh - VarLow) + VarLow;
FBest=fitnessFunc(XBest);
GB=FBest;
t = cputime;
%intialize solutions and memory
X = zeros(N, Npar);
F = zeros(N, 1);
for ii = 1:N
X(ii,:) = rand(1,Npar).* (VarHigh - VarLow) + VarLow;
% calculate the fitness of solutions
F(ii) = fitnessFunc(X(ii,:));
end
%Main Loop
for it=1:MaxIter
%Find the centre of mass
%-----------------------
%numerator term
num=zeros(1,Npar);
for ii=1:N
for jj=1:Npar
num(jj)=num(jj)+(X(ii,jj)/F(ii));
end
end
%denominator term
den=sum(1./F);
%centre of mass
Xc=num/den;
%generate new solutions
%----------------------
for ii=1:N
%new solution from centre of mass
for jj=2:Npar
New=X(ii,:);
New(jj)=Xc(jj)+((VarHigh(jj)*rand)/it^2);
end
%boundary constraints
New=limiter(New,VarHigh,VarLow);
%new fitness
newFit=fitnessFunc(New);
%check whether the solution is better than previous solution
if newFit<F(ii)
X(ii,:)=New;
F(ii)=newFit;
if F(ii)<FBest
XBest=X(ii,:);
FBest=F(ii);
end
end
end
% store the best value in each iteration
GB=[GB FBest];
end
%Main Loop
for it=1:MaxIter
%Find the centre of mass
%-----------------------
%numerator term
num=zeros(1,Npar);
for ii=1:N
for jj=1:Npar
num(jj)=num(jj)+(X(ii,jj)/F(ii));
end
end
%denominator term
den=sum(1./F);
%centre of mass
Xc=num/den;
%generate new solutions
%----------------------
for ii=1:N
%new solution from centre of mass
for jj=2:Npar
New=X(ii,:);
New(jj)=Xc(jj)+((VarHigh(jj)*rand)/it^2);
end
hi please can you help me because l have the same problem and the message related to [ New(jj)=Xc(jj)+((VarHigh(jj)*rand)/it^2);] [index exceeds number of array element(1)]?
  1 件のコメント
Aquatris
Aquatris 2020 年 5 月 31 日
VarHigh variable is a scalar not vector since you only defined it with "VarHigh = 35;" line.
And in the part that gives you the error, you are trying to reach "VarHigh(2)" which does not exist.

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BAMIDELE JEGEDE
BAMIDELE JEGEDE 2020 年 5 月 31 日
編集済み: Walter Roberson 2021 年 6 月 4 日
I have the issue with my code
clear, clc
x = 0:0.01:pi
y = myfunc(x)
plot(x,y)
avg_y = y(1:length(x)-1) + diff(y)/2;
A = sum(diff(x).*avg_yin )
at
avg_y = y(1:length(x)-1) + diff(y)/2;
I honestly don't know what I am doing wrong and it's becoming frustrating
  3 件のコメント
Walter Roberson
Walter Roberson 2021 年 2 月 12 日
v1(1)=u1(1);
You initialize one v1 value
for i=2:n
x1(i)=h*cos(z1(i-1))*v1(i-1) - memo(x1, c1, i);
When i = 3, you access v1(3-1) -> v1(2) . But that does not exist.
y1(i)=h*sin(z1(i-1))*v1(i-1)-memo(y1, c2, i);
z1(i)=h*w1(i-1)-memo(z1, c3, i) ;
end
You keep extending x1 and y1 and z1 in that loop, but you do not extend v1 or w1

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Sara Babaie
Sara Babaie 2021 年 2 月 12 日
I need some help with my code...I am getting the same error:
format long
ep=0.8; %Radiative emissivity of the pipe surface
stfb=5.67e-08; %Stefan-Boltzmann constant
q=500; %heat rate
tair=270; %air temperature
tsurr=270; %surrounding temperature
h=10; %convective heat coefficient
d=0.1; %diameter of the pipe
L=0.5; %length of pipe
p=pi;
ft=@(t84)q-(p*d*L(h*(t84-tair)+(ep*stfb(t84^4-tsurr^4))))
a=ft(334)
  3 件のコメント
Walter Roberson
Walter Roberson 2021 年 2 月 12 日
In this case, Sara's error is in forgetting a multiplication symbol. stfb*(t84^4-tsurr^4)

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Simon Hudon-Labonté
Simon Hudon-Labonté 2021 年 3 月 9 日
function [xsol]=NewtonRaphson(Fon,DerFon,SolEst,Erreur,jmax)
iflag=0;
for j=1:jmax
xsoli=SolEst-(Fon(SolEst)/DerFon(SolEst));
if abs((xsoli-SolEst)/SolEst)<Erreur
xsol=xsoli;
iflag=1;
break
end
SolEst=xsoli;
end
if j==jmax && iflag~=1
fprintf('Aucune solution après %i itérations.\n',jmax)
xsol=('Aucune réponse');
end
Hello i am getting the same error as the others in the comment but even with the different answers I cannot find my error. Thank you!
Simon
  4 件のコメント
Walter Roberson
Walter Roberson 2021 年 6 月 3 日
sum =sum +freq(i);
You do not define freq() in the code.

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Wu Changjin Wu
Wu Changjin Wu 2021 年 6 月 4 日
can some one help me, I got the same error !
% Read in image.
grayImage = imread('FFT.JPG');
[rows, columns, numberOfColorChannels] = size(grayImage)
if numberOfColorChannels > 1
grayImage = rgb2gray(grayImage);
end
% Display original grayscale image.
subplot(2, 3, 1);
imshow(grayImage)
axis on;
title('Original Gray Scale Image', 'FontSize', fontSize)
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Perform 2D FFTs
fftOriginal = fft2(double(grayImage));
% Move center from (1,1) to (129, 129) (the middle of the matrix).
shiftedFFT = fftshift(fftOriginal);
subplot(2, 3, 2);
scaledFFTr = 255 * mat2gray(real(shiftedFFT));
imshow(log(scaledFFTr), []);
title('Log of Real Part of Spectrum', 'FontSize', fontSize)
subplot(2, 3, 3);
scaledFFTi = mat2gray(imag(shiftedFFT));
imshow(log(scaledFFTi), []);
axis on;
title('Log of Imaginary Part of Spectrum', 'FontSize', fontSize)
% Display magnitude and phase of 2D FFTs
subplot(2, 3, 4);
shiftedFFTMagnitude = abs(shiftedFFT);
imshow(log(abs(shiftedFFTMagnitude)),[]);
axis on;
colormap gray
title('Log Magnitude of Spectrum', 'FontSize', fontSize)
% Get average
midRow = rows/2+1
midCol = columns/2+1
maxRadius = ceil(sqrt(129^2 + 129^2))
radialProfile = zeros(maxRadius, 1);
count = zeros(maxRadius, 1);
for col = 1 : columns
for row = 1 : rows
radius = sqrt((row - midRow) ^ 2 + (col - midCol) ^ 2);
thisIndex = ceil(radius) + 1;
radialProfile(thisIndex) = radialProfile(thisIndex) + shiftedFFTMagnitude(row, col);
count(thisIndex) = count(thisIndex) + 1;
end
end
radialProfile = radialProfile./ count;
subplot(2, 3, 5:6);
plot(radialProfile, 'b-', 'LineWidth', 2);
grid on;
title('Average Radial Profile of Spectrum', 'FontSize', fontSize)
  1 件のコメント
Walter Roberson
Walter Roberson 2021 年 6 月 4 日
fontSize = 12;
% Read in image.
filename = 'FFT.JPG';
if isunix()
filename = 'flamingos.jpg';
end
grayImage = imread(filename);
[rows, columns, numberOfColorChannels] = size(grayImage);
if numberOfColorChannels > 1
grayImage = rgb2gray(grayImage);
end
% Display original grayscale image.
subplot(2, 3, 1);
imshow(grayImage)
axis on;
title('Original Gray Scale Image', 'FontSize', fontSize)
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);
% Perform 2D FFTs
fftOriginal = fft2(double(grayImage));
% Move center from (1,1) to (129, 129) (the middle of the matrix).
shiftedFFT = fftshift(fftOriginal);
subplot(2, 3, 2);
scaledFFTr = 255 * mat2gray(real(shiftedFFT));
imshow(log(scaledFFTr), []);
title('Log of Real Part of Spectrum', 'FontSize', fontSize)
subplot(2, 3, 3);
scaledFFTi = mat2gray(imag(shiftedFFT));
imshow(log(scaledFFTi), []);
axis on;
title('Log of Imaginary Part of Spectrum', 'FontSize', fontSize)
% Display magnitude and phase of 2D FFTs
subplot(2, 3, 4);
shiftedFFTMagnitude = abs(shiftedFFT);
imshow(log(abs(shiftedFFTMagnitude)),[]);
axis on;
colormap gray
title('Log Magnitude of Spectrum', 'FontSize', fontSize)
% Get average
midRow = rows/2+1;
midCol = columns/2+1;
%maxRadius = ceil(sqrt(129^2 + 129^2))
maxRadius = ceil(sqrt(midRow.^2 + midCol.^2));
radialProfile = zeros(maxRadius, 1);
count = zeros(maxRadius, 1);
for col = 1 : columns
for row = 1 : rows
radius = sqrt((row - midRow) ^ 2 + (col - midCol) ^ 2);
thisIndex = ceil(radius) + 1;
radialProfile(thisIndex) = radialProfile(thisIndex) + shiftedFFTMagnitude(row, col);
count(thisIndex) = count(thisIndex) + 1;
end
end
radialProfile = radialProfile./ count;
subplot(2, 3, 5:6);
plot(radialProfile, 'b-', 'LineWidth', 2);
grid on;
title('Average Radial Profile of Spectrum', 'FontSize', fontSize)

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ELIZABETH ESPARZA
ELIZABETH ESPARZA 2021 年 6 月 5 日
Hi, i have the same error, i need help :(
clear all
%incremento en x
h=0.1;
%funcion 1
f = @(t,a,b,u,v,w) -5*a*u+2*a-4*b;
%funcion 2
g = @(t,a,b,u,v,w) -a*b*v-a+6*b;
%funcion 3
d = @(t,a,b,u,v,w) b*w-a;
%Condiciones Iniciales
ti = 0;
ai = 0;
bi = 0;
ui = 0;
vi = 0;
wi = 00;
%Iteraciones
n = 5;
%Función
[t,a,b,u,v,w] =RungeFG3(f,g,d,n,h,ti,ai,bi,ui,vi,wi)
%Graficación
plot3(t,a,b);grid on;
legend('Runge K4')
title('Gráfica')
xlabel('t')
ylabel('a')
zlabel('b')
tabla1= table (t',a',b');
tabla1.Properties.VariableNames = {'t','a','b'}
function [t,a,b,u,v,w] =RungeFG3(f,g,d,n,h,t0,a0,b0,u0,v0,w0)
t(1) = t0;
a(1) = a0;
b(1) = b0;
u(1) = u0;
v(1) = v0;
w(1) = w0;
for i=1:1:n
t(i+1) = t(i) + h;
k1 = h*f(t(i),a(i),b(i),u(i),v(i),w(i));
l1 = h*g(t(i),a(i),b(i),u(i),v(i),w(i));
e1 = h*d(t(i),a(i),b(i),u(i),v(i),w(i));
m1 = h*u(i);
n1 = h*v(i);
p1 = h*w(i);
k2 = h*f(t(i)+h/2,a(i)+m1/2,b(i)+n1/2,u(1)+k1/2,v(i)+l1/2,w(i)+l1/2);
l2 = h*g(t(i)+h/2,a(i)+m1/2,b(i)+n1/2,u(1)+k1/2,v(i)+l1/2,w(i)+l1/2);
e2 = h*d(t(i)+h/2,a(i)+m1/2,b(i)m2 = h*(u(i)+k1/2);
n2 = h*(v(i)+l1/2);
p2 = h*(w(i)+p1/2);
k3 = h*f(t(i)+h/2,a(i)+m2/2,b(i)+n2/2,u(1)+k2/2,v(i)+l2/2,w(i)+l2/2);
l3 = h*g(t(i)+h/2,a(i)+m2/2,b(i)+n2/2,u(1)+k2/2,v(i)+l2/2,w(i)+l2/2);
e3 = h*d(t(i)+h/2,a(i)+m2/2,b(i)+n2/2,u(1)+k2/2,v(i)+l2/2,w(i)+l2/2);
m3 = h*(u(i)+k2/2);
n3 = h*(v(i)+l2/2);
p3 = h*(w(i)+p2/2);
k4 = h*f(t(i)+h,a(i)+m3,b(i)+n3,u(1)+k3,v(i)+l3,w(i)+l3);
l4 = h*g(t(i)+h,a(i)+m3,b(i)+n3,u(1)+k3,v(i)+l3,w(i)+l3);
e4 = h*d(t(i)+h,a(i)+m3,b(i)+n3,u(1)+k3,v(i)+l3,w(i)+l3);
m4 = h*(u(i)+k3);
n4 = h*(v(i)+l3);
p4 = h*(w(i)+p3);
u(i+1) = u(i)+(k1+2*k2+2*k3+k4)/6;
v(i+1) = v(i)+(l1+2*l2+2*l3+l4)/6;
p(i+1) = w(i)+(p1+2*p2+2*p3+p4)/6;+n1/2,u(1)+k1/2,v(i)+l1/2,w(i)+l1/2);
a(i+1) = a(i)+(m1+2*m2+2*m3+m4)/6;
b(i+1) = b(i)+(n1+2*n2+2*n3+n4)/6;
end
end
  5 件のコメント
Aquatris
Aquatris 2021 年 6 月 6 日
That index problem happens because of variable w. You never assigned values to w(i+1) in your code.

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emre bahçeci
emre bahçeci 2021 年 6 月 15 日
Hello,i am trying to face same error.Here is my code:
T=1.5
t=0:0.001:T
m=1;b=10;k=100;
K=[1 0 0 0 0 0;
0 1 0 0 0 0;
0 0 2 0 0 0;
1 T T^2 T^3 T^4 T^5;
0 1 2*T 3*T^2 4*T^3 5*T^4;
0 0 2 6*T 12*T^2 20*T^3]
A=inv(K)*[pi/3;0;0;5*pi/3;0;0]
syms theta(x)
theta_dot=diff(theta,x)
theta_dot_dot=diff(theta_dot,x)
Q=m*theta_dot_dot+b*theta_dot+k*theta
for i=1:length(t)
teta(i)=A(1)+A(2)*t(i)+A(3)*t(i)^2+A(4)*t(i)^3+A(5)*t(i)^4+A(6)*t(i)^5
tetah(i)=A(2)+2*A(3)*t(i)+3*A(4)*t(i)^2+4*A(5)*t(i)^3+5*A(6)*t(i)^4
tetai(i)=2*A(3)+6*A(4)*t(i)+12*A(5)*t(i)^2+20*A(6)*t(i)^3
Q_new(i)=subs(Q,[theta_dot_dot theta_dot theta],[tetai tetah teta])
end
After that i have encountered same error:
Index exceeds the number of array elements (1).
Error in sym/subs>normalize (line 212)
Y{i} = fun2sym(Y{i},argnames(X{i}));
Error in sym/subs>mupadsubs (line 166)
[X2,Y2,symX,symY] = normalize(X,Y); %#ok
Error in sym/subs (line 154)
G = mupadsubs(F,X,Y);
Error in symbolic_in_for_loop (line 19)
Q_new(i)=subs(Q,[theta_dot_dot theta_dot theta],[tetai tetah teta])
Can anybody help me?
Thanks
  2 件のコメント
emre bahçeci
emre bahçeci 2021 年 6 月 16 日
Thanks a lot

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