Updating a Property in an Array of Objects

I have a class called WorkOrder that contains of several properties. My program brings in data from a SQL database as a Matlab table to be used as property values.. Once the data is imported, I check the height of the table and instatiate that exact amount of WorkOrder objects in a an array. I would now like to update the each of WorkOrder.properties by using the following type of statement:

[WorkOrder(1,:,1).wonbr] = listData.WONbr{:,1};

The above code works fine if the SQL datatype is a character string. However it fails if the SQL datatype is numeric with the error message: Brace indexing is not supported for variables of this type. But if I change the indexing to parentheses as below, I receive the error: Error using tabular/dotParenReference Too many output arguments.

[WorkOrder(1,:,1).nid] = listData.nid(:,1);

I could use a for loop as below, but it is too slow when the number of WorkOrder objects is high.

for i = 1:height(listData)
    WorkOrder(i).nid = listData.nid(i,1);     
end

Is there a way to make the middle statement above work for numberic data?

Answer 1

[per isakson]

The documentation doesn't tell that a statement like [WorkOrder(1,:,1).nid] = listData.nid(:,1); isn't possible. You are not the first one to try in vain. See Generate a comma-separated list from a numeric array?

I don't fully understand your code snippets. However, I made a working example.

Run

%%  Example table from the documentation
load patients
T = table(Gender,Age,Height,Weight,Smoker,Systolic,Diastolic);
%%  Create an array of WorkOrder objects 
wo = WorkOrder( height(T) );
%%  Update the properties of the WorkOrder objects 
[wo.wonbr] = T.Gender{:,1};
[wo.nid] = num2csl( T.Height );

where

function    varargout = num2csl( num )
% num2csl converts a numerical vector into a comma separated list
    assert( isnumeric(num), 'num2csl:WrongClass', 'Input must be numeric' )
    cac = num2cell( num );
    varargout = cac( 1 : nargout );
end

and

classdef    WorkOrder
    properties
        wonbr
        nid
    end
    methods
        function    this = WorkOrder( N )
            if nargin >= 1
                this(1,N) = WorkOrder;
                for jj = 1:N
                    this(jj).nid = nan;
                end
            end
        end
    end
end

[Clarke]

Thanks PI, that did the trick. Any idea why we need the function workaround for an int64 datatype, but not a string? Just curious. I am already using the function.

[Clarke]

PS. The page is not letting me accept the answer. I reload, but no joy. Will try again later today or tommorow.