what this matlab syntax var1= input.var2 corresponds to ?

Hello, i'm beginner in matlab and i'm asking for help, can someone tell me the signification of this matlab syntax ?

function [output1, output2] = BagOfWords(input, mode, geneIndex, dataForCurrentGene)
switch mode
    case 'init'
        data              = input.data;
        nGenesOverall     = input.nGenes;
        nFeatures         = input.nFeatures;
        maxNumberOfComponents = input.maxNumberOfComponents;
        sparseMatrix      = zeros(nGenesOverall,nFeatures);
        sparseVector      = false(1,nGenesOverall);
        
        % Define the cluster structure
        clusterStruct(1,maxNumberOfComponents) = struct(...
            'nFeatures', [], ...
            'nGenesOverall', [], ...
            'beta', [], ...
            'sumBeta',[],...
            'nGenes', [], ...
            'logMarginalLikelihood', [],...
            'dataCounts', [], ...
            'logicalGeneIDs', [], ...
            'N', []);
  

I didn't understand if input is a simple argument of the function BagOfWords or it refers to requesting user input? Else, what do these instructions (example: nGenesOverall = input.nGenes ) mean ?

[Stephen23]

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-structure-array.html

Answer 1

[Brent Kostich]

Regarding this segment of code

BagOfWords(input, mode, geneIndex, dataForCurrentGene)

Everything inside the parenthesis is an input argument to the function BagOfWords. In the case of this funtion, input is a structure array. The dot notation references data in different fields of that array. For example:

input.nGenes follows the form struct.field

Since you are new to MATLAB, the above example is just a primer. I would encouage you to read through some of the documentation or look into Onramp to learn more about the syntax.

https://www.mathworks.com/help/matlab/ref/function.html

https://www.mathworks.com/help/matlab/ref/struct.html

https://www.mathworks.com/learn/tutorials/matlab-onramp.html

Answer 2

[Fangjun Jiang]

It is called struct. Follow the link to see the document and you can try youself.

input.var2=2;
input.var3=rand(3);
MyVar=input.var3