Error: Function definitions are not permitted in this context.

This is my function

function [ area ] = calcarea(rad )

area = pi*rad.^2

end

When I try to run it, following message shows up, "The selected section cannot be evaluated because it contains an invalid statement

Also, the command window says "Error: Function definitions are not permitted in this context"

What am I doing wrong???

[Nabin SUNAM]

It worked after I saved the file with the same filename as my function, i.e my filename was not calcarea.m before, once I renamed the filename as calcarea.m, it started functioning. I had to call the function in the command window though.

Answer 1

[Image Analyst]

You probably have that function below a script in your m-file. You can't mix a script and a function in the same file. You can have two functions though. So if your file is called test.m, you could have all this in the single file:

function test()
    area = calcarea(10)
end

function area = calcarea(rad)
    area = pi*rad.^2;
end

Or you could have them in two separate files:

A script in test.m:

area = calcarea(10)

A function in calcarea.m:

function area = calcarea(rad)
    area = pi*rad.^2;
end

[Nabin SUNAM]

My function started working after I renamed the file i.e. renamed as calcarea. So, I guess functions need to be saved with the same filename.

Thank you for the response.

[Image Analyst]

They should , but they don't have to be. For example, if you save this as test2.m, it works fine:

function test1()
fprintf('The time is %s\n', datestr(now));

even though the function is declared as test1 instead of test2. Try it if you want to double check what I said. So renaming your file was not the problem - it was something else. But whatever - as long as it's working now.

[Sanjiv Kumar]

Sir I am still getting the same problem even after saving the file same as used in the function

[Image Analyst]

Attach your m-file(s) in a new question (not here in Nabin's question).

[Walter Roberson]

Sanjiv Kumar what happened when you followed the instructions I gave in your Question to install the contents of the .zip I provided for you?

Answer 2

[Star Strider]

You have to put functions such as yours in their own separate .m-files. In your situation, you would save it as: calcarea.m, and to run it from your main script, you would call it as:

area = calcarea(rad)

[Nabin SUNAM]

Yes, my problem was I saved the file with different filename. It started working when I renamed the file. Thanks for the quick reply.

[Star Strider]

My pleasure!

Answer 3

[bahadir safak]

sigma=1;
thresh=1000;
disp=1;
radius=1
im=imread('11.jpg');

function [cim, r, c] = harris(im, sigma, thresh, radius, disp)

      error(nargchk(2,5,nargin));

      dx = [-1 0 1; -1 0 1; -1 0 1]; % Derivative masks
      dy = dx';

      Ix = conv2(im, dx, 'same');    % Image derivatives
      Iy = conv2(im, dy, 'same'); 

??? Error: File: harris1.m Line: 45 Column: 1
Function definitions are not permitted in this context.

>>

???

[Image Analyst]

You can't have a script, followed by a function in the same file. But you can have two functions, so add this to the top of the file

function harris1()

or else split those up into two different files.

[bahadir safak]

function harris1()

sigma=1;

thresh=1000;

disp=1;

radius=1;

im=imread('11.jpg');

function [cim, r, c] = harris(im, sigma, thresh, radius, disp)

      error(nargchk(2,5,nargin));
      dx = [-1 0 1; -1 0 1; -1 0 1]; % Derivative masks
      dy = dx';
      Ix = conv2(im, dx, 'same');    % Image derivatives
      Iy = conv2(im, dy, 'same');

NOT Working!!

[Image Analyst]

Of course not bahadir. You never even called harris() in your main program! Not only that, but you didn't even define what your output variables are. Try this:

function harris1()
clc;
sigma=1;
thresh=1000;
disp=1;
radius=1;
im=imread('cameraman.tif');
dblIm = double(im);
[cim, r, c] = harris(dblIm, sigma, thresh, radius, disp);

function [cim, r, c] = harris(im, sigma, thresh, radius, disp)

error(nargchk(2,5,nargin));
dx = [-1 0 1; -1 0 1; -1 0 1]; % Derivative masks
dy = dx';
Ix = conv2(im, dx, 'same');    % Image derivatives
Iy = conv2(im, dy, 'same');
% Define output variables.
cim = rand % Whatever it's supposed to be....
r = rand
c = rand

[Mohammedashraf Shaikh]

function[d] = hcompare_EMD(h1,h2)

d = sum(abs(cumsum(h1) - cumsum(h2)));
end

img = imread('C:\Users\Hp\Desktop\col\001.jpg');

function[h] = histImage(img)

% This function calculates normalized histogram of image.

% Normalized histogram is histogram h, that has at

% each i place in it, value:

% (number of picture pixels with gray level i-1) / 

% (total num of pixels in picture).

sum = 0;

[y,x] = size(img); % getting sizes of image 

h = zeros(1,256);    % creating output histogram array

for i = 1:1: y     % runing on rows

      for j = 1:1: x % running on colomns

          % gray level is addtess to cell in output histogram array

     % we add there 1 (bacause of current pixel (y,x) has this gray level

h(img(i,j)) = h(img(i,j)) + 1;

          % pay attention to fact, that we use here pixel value as index!
      end
  end

h = h./(y*x);

end
% to calculate the distance between the histograms of the two images %%
 %(histArray, histPattern):

function[dmap] = patDistMAp(histArray, histPattern)

[y,x,z] = size(histArray);

dmap = zeros(y,x);                  % output array

for i = 1:1: y       % runing on rows

      for j = 1:1: x   % running on colomns

          hist = histArray(i,j,:);

%         for k = 1:1:256             % making array 1x256 from 1x1x256
%             h1(k) = hist(1,1,k);    % there is a permute function,
%         end                         % but we will use it next time)

          h1 = permute(squeeze(hist),[2,1]);

          % Using temp variable, as MATLAB7 wants it:

          temp = hcompare_EMD(histPattern,h1);

          dmap(i,j) = temp;

      end

end

end

[Mohammedashraf Shaikh]

in above problem i am getting problem

function[d] = hcompare_EMD(h1,h2) |

Error: Function definitions are not permitted in this context.

[Stephen23]

@Mohammedashraf Shaikh: your code is badly aligned, and this makes hiding the errors easy. Once I correctly aligned your code and put each operation on its own line, then the (first) mistake is obvious, and occurs in the first five lines of code:

function[d] = hcompare_EMD(h1,h2)
d = sum(abs(cumsum(h1) - cumsum(h2)));
end
img = imread('C:\Users\Hp\Desktop\col\001.jpg');
function[h] = histImage(img)
...

You call img = ... outside of any function.

It is also possible that your first function definition occurs after some lines of code in a script. Depending on MATLAB version, this will also cause an error. See the other answers for more info on this.

Summary: Learn to align your code consistently (use the MATLAB defaults), and do not put multiple operators onto one line (especially the end for functions!). You can automatically align the code in the MATLAB Editor: select all code, then press ctrl+i.

[Image Analyst]

And learn to format your posts by watching this tutorial Click here

Answer 4

[Rwigema james]

function Iout = readAndPreprocessImage(filename)
        I=imread(filename);
        if ismatrix(I)
            I = cat(3,I,I,I);
       end
       Iout = imresize(I,[227 227]);
end

Why am I getting this error?????

Function definitions are not permitted in this context.

[Image Analyst]

You're putting the function definition in a place where it does not belong, such as below a script in release R2016a and earlier, or elsewhere.

[Abbas Khreis]

i have 2016a version and the error Function definitions are not permitted in this con

plz help me

Answer 5

[Elena MEZZAPESA]

Hello, Did you solve the issues to this problem in the end? As of 2017 I still get this error ?! I am trying to understand if it is because I am using a trial version of the software. Best regards,

Elena

[Image Analyst]

It was masked as being solved. The trial version is no different than a full version other than being time-limited to 30 days. We'd have to see your code to figure out what's going wrong with your program.

Answer 6

[Frieder Wittmann]

This is one of the main disadvantages of MATLAB notebooks over Jupyter (python) notebooks. If I can't define functions in the middle of a script, the notebook becomes hard to read.

[Walter Roberson]

Since R2016b, MATLAB has permitted functions to be defined inside script files.

[Abbas Khreis]

clc
clear all
function y=BUBBLE_SORT(x)
N= length(x);
if N<2 
    y=x;
    
    return;
end
    
for i=1:N-1 ;
    
    if(x(i)>x(i+1))
        t=x(i);
        x(i)=x(i+1);
        x(i+1)=t;
    end
    
end
y=BUBBLE_SORT(x(1:N-1));
y=[y x(N)];
end

this code giving me error

'''Error: File: BUBBLE_SORT.m Line: 3 Column: 11

Function definitions are not permitted in this context.'''

[Walter Roberson]

You are using R2016a or earlier, which did not permit functions to be mixed with scripts.

If you had been using R2016b or later, you would have seen a different error, complaining about function name conflicts. In versions that permit a function to be defined in a script file, it is not permitted for one of the functions to have the ame name as the script file.

[Frieder Wittmann]

Hi thanks for your reply. Im using R2019a. Here is an example. Filename is test.m

a = 5
b = 10

function y = multiplyNumbers(a,b)
    y = a * b;
end

y = multiplyNumbers(a,b)

Error: File: test.m Line: 8 Column: 1

Function definitions in a script must appear at the end of the file.

Move all statements after the "multiplyNumbers" function definition to before the first local function definition.

----

Moving the function defintion to the end of the script forces the reader to jump around. At first they might not even realize, that it's a costum function that they will find at the end of the script. In Jupyter the equivalent of the above script would have worked.

[Walter Roberson]

MATLAB is not Jupityr.

[Frieder Wittmann]

It isn't, it's one of the most common competitors.