How to convert mxarray datatype in simulink

I have to remove small objects from binary image and Im trying to use bwareaopen in simulink by using following code:

function y = fcn(u)
x = zeros(size(u));
coder.extrinsic('bwareaopen');
x = bwareaopen(u, 50);
y = double(x);

and getting error:

Class mismatch for variable 'bwareaopen'. Expected 'double', Actual 'logical'. Block MATLAB Function (#24) While executing: none

Model is as follows:

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Answer 1

[Ryan Livingston]

For allocating logical data use either of the functions true or false:

x = true(size(u));
x = false(size(u));

[Nazim Badar]

Thanks 4 your support.... Its working Now.

[Sayed Rizban Hussain]

I have done the same thing but getting an error. I am using matlab2016a.

"The extrinsic function 'xor' is not available for standalone code generation. It must be eliminated for stand-alone code to be generated. It could not be eliminated because its outputs appear to influence the calling function. Fix this error by not using 'xor' or by ensuring that its outputs are unused."

"The extrinsic function 'bwareaopen' is not available for standalone code generation. It must be eliminated for stand-alone code to be generated. It could not be eliminated because its outputs appear to influence the calling function. Fix this error by not using 'bwareaopen' or by ensuring that its outputs are unused."

this is my code:

    function y = fcn(u)

    coder.extrinsic('bwareaopen');
    coder.extrinsic('xor');
    noSmallStructure = false(size(u));

    noSmallStructure = xor(bwareaopen(u, 15),bwareaopen(u, 862));;
    y = double(noSmallStructure);
    end

i really need help to get rid of this errors. Thanks in advance

%

[Walter Roberson]

xor can be replaced by ~=

In R2016a bwareaopen is supported for code generation, but there is a notation about "MATLAB Function Block support: No". I am not sure what that implies at the moment. It might mean that it is supported by MATLAB Coder but not by Simulink Coder -- since Simulink Coder is for deploying to targets, there could be a difference in support.

[Sayed Rizban Hussain]

yes bwareaopen is supported in matlab coder as I have used it previously. Now my target machine is raspberry pi. Can you suggest me any function that can replace bwareaopen? As for my application I only need objects of a specific area range.

[Walter Roberson]

bwlabel and count the number of matches of each label?

Answer 2

[Kaustubha Govind]

It looks like bwareaopen returns an output of type logical. You need to pre-declare 'x' as follows:

x = zeros(size(u), 'logical');

[Nazim Badar]

Thanks Kaustubha for your response, I tried declaring as you suggested but get following error:

Invalid value 'logical' for the trailing string argument. This argument must be a valid numeric class name: 'double', 'single', 'int8', 'uint8', 'int16', 'uint16', 'int32', or 'uint32'.

Function 'MATLAB Function' (#34.34.58), line 3, column 5:
"zeros(size(u),'logical')"
Launch diagnostic report.

Still not able to declare correctly.