All functions in a script must be closed with an 'end'.

hello~

I'm having trouble calculating the prediction ellipse

Can someone help me?

this message error :

Error: File: PEA.m Line: 67 Column: 24
All functions in a script must be closed with an 'end'. 

the script such as

chisquare = chi2inv(0.95,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P = 0.95 
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues 
PEA = pi*chisquare*prod(sqrt(svd(val))) %area calculation


function a = PEA(x,y,P)
%
%a = PEA(x,y,P): plots a prediction ellipse of the center of 
%pressure (COP) data separated into x and y components with probability 
%value P and calculates the prediction ellipse area (PEA)
%
%inputs: 
% x,y: data (column vectors)
% P  : a value of the interval (0,1)
%
%output:
% a  : represents the area of the ellipse
%
%type PEA without inputs to plot 95% prediction ellipse of exemplary data
 
%%
%exemplary data illustration
if nargin==0 %case of no input arguments 
    x = [2,4,6,2,3,4,2,3,3,4,5,5,0,8,3,7]; %exemplary x component
    y = [1,2,3,4,3,3,1,1,2,1,4,5,0,0,1,1]; %exemplary y component
    a = PEA(x,y,0.95);
    axis([-4 11 -3 7])
    title('95% PEA of exemplary data')
    text(-3,6,'blue points = data')
    text(5.5,2,'major axis')
    text(4.3,0,'minor axis')
    text(7,-2,['PEA: ' num2str(a)])
    return %end of function
end 
%%
 
%begin of function
 
chisquare = chi2inv(P,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P
x = x(isfinite(x));
y = y(isfinite(y));
mx = mean(x);
my = mean(y);
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues
a = pi*chisquare*prod(sqrt(svd(val))); %area calculation
 
hold on
 
%COP data
plot(x,y,'b.'); 
 
%ellipse
N = 100; %fixed value (the higher the smoother the ellipse)
t = linspace(0,2*pi,N);
elip = sqrt(chisquare)*vec*sqrt(val)*[cos(t); sin(t)] + repmat([mx; my],1,N);
elip = elip';
line(elip(:,1),elip(:,2),'Color', [0 0 0], 'LineWidth', 1);
 
%major and minor axes
ax1 = sqrt(chisquare)*vec*sqrt(val)*[-1,1; 0,0] + repmat([mx; my],1,2);
ax2 = sqrt(chisquare)*vec*sqrt(val)*[0,0; -1,1] + repmat([mx; my],1,2);
ax_dat = [ax1'; NaN,NaN; ax2'];
line(ax_dat(:,1),ax_dat(:,2),'Color',[0 0 0],'LineWidth', 1);
 
axis equal
 
return %end of function

Answer 1

[Matt J]

Replace "return" by "end"

[Tsu Ming Chang]

you mean like that?

 end of function %return

[Matt J]

Like this:

t=add_one(5)

t = 6

function y=add_one(x)

  y=x+1;

end

[Tsu Ming Chang]

but it still wrong

[Matt J]

It's certainly possible that you still have mistakes in your code, but I've demonstrated that my answer fixes the particular mistake that you asked about in your post. Therefore, you should Accept-click the answer and raise other problems you are having in a different thread.

Answer 2

[Walter Roberson]

Delete or comment out everything from the "function" line.

• Your script never invokes the function
• functions inside a script cannot be reached from outside the script (unless somehow the outside gets a handle to it)
• your function is named PEA but your script is also named PEA and you assign to a variable named PEA. Once you execute the script PEA the calling context would have a variable PEA and variables with a name have a higher priority than scripts or functions with the same name, so the function would be unreachable anyhow.

[Tsu Ming Chang]

I change it but still wrong

chisquare = chi2inv(0.95,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P = 0.95 
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues 
pea = pi*chisquare*prod(sqrt(svd(val))) %area calculation
% End of script part of m-file

%====================================================================================
% Now define a function.
function a = ComputePEA(x,y,P)
%
%a = PEA(x,y,P): plots a prediction ellipse of the center of 
%pressure (COP) data separated into x and y components with probability 
%value P and calculates the prediction ellipse area (PEA)
%
%inputs: 
% x,y: data (column vectors)
% P  : a value of the interval (0,1)
%
%output:
% a  : represents the area of the ellipse
%
%type PEA without inputs to plot 95% prediction ellipse of exemplary data

%%
%exemplary data illustration
if nargin==0 %case of no input arguments 
    x = [2,4,6,2,3,4,2,3,3,4,5,5,0,8,3,7]; %exemplary x component
    y = [1,2,3,4,3,3,1,1,2,1,4,5,0,0,1,1]; %exemplary y component
    a = ComputePEA(x,y,0.95);
    axis([-4 11 -3 7])
    title('95% PEA of exemplary data')
    text(-3,6,'blue points = data')
    text(5.5,2,'major axis')
    text(4.3,0,'minor axis')
    text(7,-2,['PEA: ' num2str(a)])
    return %end of function
end 
%%

%begin of function

chisquare = chi2inv(P,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P
x = x(isfinite(x));
y = y(isfinite(y));
mx = mean(x);
my = mean(y);
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues
a = pi*chisquare*prod(sqrt(svd(val))); %area calculation

hold on

%COP data
plot(x,y,'b.'); 

%ellipse
N = 100; %fixed value (the higher the smoother the ellipse)
t = linspace(0,2*pi,N);
elip = sqrt(chisquare)*vec*sqrt(val)*[cos(t); sin(t)] + repmat([mx; my],1,N);
elip = elip';
line(elip(:,1),elip(:,2),'Color', [0 0 0], 'LineWidth', 1);

%major and minor axes
ax1 = sqrt(chisquare)*vec*sqrt(val)*[-1,1; 0,0] + repmat([mx; my],1,2);
ax2 = sqrt(chisquare)*vec*sqrt(val)*[0,0; -1,1] + repmat([mx; my],1,2);
ax_dat = [ax1'; NaN,NaN; ax2'];
line(ax_dat(:,1),ax_dat(:,2),'Color',[0 0 0],'LineWidth', 1);

axis equal

end % end of function

and

Unrecognized function or variable 'x'.

Error in pea_test (line 2)
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues

[Walter Roberson]

Where are you defining x?

Answer 3

[Image Analyst]

Try this:

chisquare = chi2inv(0.95,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P = 0.95 
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues 
P = whateverItIs;
a = PEA(x,y,P)
% End of script part of m-file

%====================================================================================
% Now define a function.
function a = PEA(x,y,P)
%
%a = PEA(x,y,P): plots a prediction ellipse of the center of 
%pressure (COP) data separated into x and y components with probability 
%value P and calculates the prediction ellipse area (PEA)
%
%inputs: 
% x,y: data (column vectors)
% P  : a value of the interval (0,1)
%
%output:
% a  : represents the area of the ellipse
%
%type PEA without inputs to plot 95% prediction ellipse of exemplary data

%%
%exemplary data illustration
if nargin==0 %case of no input arguments 
    x = [2,4,6,2,3,4,2,3,3,4,5,5,0,8,3,7]; %exemplary x component
    y = [1,2,3,4,3,3,1,1,2,1,4,5,0,0,1,1]; %exemplary y component
    a = PEA(x,y,0.95);
    axis([-4 11 -3 7])
    title('95% PEA of exemplary data')
    text(-3,6,'blue points = data')
    text(5.5,2,'major axis')
    text(4.3,0,'minor axis')
    text(7,-2,['PEA: ' num2str(a)])
    return %end of function
end 
%%

%begin of function

chisquare = chi2inv(P,2); %inverse of the chi-square cumulative distribution function with 2 degrees of freedom at P
x = x(isfinite(x));
y = y(isfinite(y));
mx = mean(x);
my = mean(y);
[vec,val] = eig(cov(x,y)); %calculation of eigenvalues
a = pi*chisquare*prod(sqrt(svd(val))); %area calculation

hold on

%COP data
plot(x,y,'b.'); 

%ellipse
N = 100; %fixed value (the higher the smoother the ellipse)
t = linspace(0,2*pi,N);
elip = sqrt(chisquare)*vec*sqrt(val)*[cos(t); sin(t)] + repmat([mx; my],1,N);
elip = elip';
line(elip(:,1),elip(:,2),'Color', [0 0 0], 'LineWidth', 1);

%major and minor axes
ax1 = sqrt(chisquare)*vec*sqrt(val)*[-1,1; 0,0] + repmat([mx; my],1,2);
ax2 = sqrt(chisquare)*vec*sqrt(val)*[0,0; -1,1] + repmat([mx; my],1,2);
ax_dat = [ax1'; NaN,NaN; ax2'];
line(ax_dat(:,1),ax_dat(:,2),'Color',[0 0 0],'LineWidth', 1);

axis equal

end % end of function

[Tsu Ming Chang]

I tried it and it gives this error

Error: File: PEA.m Line: 8 Column: 14
Local function name must be different from the script name.

[Image Analyst]

You can't call the function PEA, like it says. You can either

1. Call the m-file "pea_test.m" and leave the function called "PEA", or
2. Call the function "ComputePEA" and leave the file called PEA.m

[Tsu Ming Chang]

I change my file name call "pea_test.m" but it said this

Error: File: pea_test.m Line: 3 Column: 1
Declaring a variable with the same name as the local function "PEA" is not supported in
scripts.

[Image Analyst]

You didn't notice these lines of code:

a = PEA(x,y,P)
% End of script part of m-file
%====================================================================================
% Now define a function.
function a = PEA(x,y,P)

Note how I took the result of calling PEA and put it into "a"? You didn't do that. You still have

PEA = pi*chisquare*prod(sqrt(svd(val))) %area calculation

You can't define a new variable called PEA when you already have a function of that name. And, as with all computer languages that I know of, the function is on the right side of the = sign, and the result gets put into the variable on the left side of the = sign.