Making a table with different column widths and autofit contents

I am trying to make a table with three different column widths and I just can't seem to get it right.

When I use ColWidth in any of the following formats:

Alltb(1,1)=ColWidth('1in');

Alltb.ColWidth='1in';

Alltb.entry(1,1).Style = {ColWidth('1in')};

Alltb.Children.entry(1,1).Style = {ColWidth('1in')};

Alltb.Children.Entries(1,1).Style = {ColWidth('1in')};

I get an error that that doesn't exist, some variation of:

Unrecognized property 'ColWidth' for class 'mlreportgen.dom.TableEntry'.

I don't understand what mistake I'm making. Alltb is defined as a "Table()". I have tried defining a table entry and then applying colwidth to that with the same problem. I am using Matlab2017b.

[Meggo]

I found ColSpecGroups which may be the correct one to use for a document whereas colwidth is used for a ppt, but I can't find a single example of how to use it. I've been looking for hours. I'm so frustrated just trying to format this stupid table.

Alltb.ColSpecGroups(1) = Width('.75in');

returns:

The following error occurred converting from mlreportgen.dom.Width to double:
Conversion to double from mlreportgen.dom.Width is not possible.

When I make the table with Alltb=Table(3) There is a ColSpecGroups argument. I just can't find any examples of how to enter in the information.

Alltb.ColSpecGroups(1) = TableColSpecGroup('0.75in');

and

Alltb.ColSpecGroups(1) = TableColSpec('0.75in');

return the same error:

No constructor 'mlreportgen.dom.TableColSpecGroup' with matching signature found.

This line:

Alltb.ColSpecGroups(1) = '0.75in';
returns: 

Subscripted assignment dimension mismatch.

This liine:

Alltb.ColSpecGroups{1} = '0.75in';
returns: 

Invalid Table column spec group.

Which is weird, because

Alltb.ColSpecGroups

ans =

       []

Answer 1

[Meggo]

I found the answer. It's stupid and unintuitive. Here is the code that worked:

        grps(1)=TableColSpecGroup;
        grps(1).Span=1;
        grps(1).Style={Width('1in')};
        grps(2)=TableColSpecGroup;
        grps(2).Span=2;
        grps(2).Style={Width('2.75')};

       Alltb.ColSpecGroups = grps;

Where Span sets the number of columns that the spec applies to.