Why does struct2table not work if you don't have more than 1 entry per field?

If I have a 1 x n struct with m fields, where n > 1, I have no issues with this function. If I have a 1 x 1 struct with m fields, I get this error:

Error using table.fromScalarStruct (line 480)
Fields in a scalar structure must have the same number of rows.

This function should not have this error. It should work exactly the same and produce a table with m columns and 1 row. Why is this not happening?

[Jan]

Could you please add some lines of code, which reproduce this error?

Answer 1

[Walter Roberson]

If you look at https://www.mathworks.com/help/matlab/ref/struct2table.html#examples you can see that the expectation for a scalar structure is that multiple rows are created.

[Alex]

Right. Thank you, but that wasn't my question. My question was, why is it designed that way?

[Walter Roberson]

That was not your question. You wrote,

"This function should not have this error. It should work exactly the same and produce a table with m columns and 1 row. "

Which is contrary to the documented behavior of the function. You want to impose behavior upon the function designers instead of reading the documentation to find out what the function does.

See in particular https://www.mathworks.com/help/matlab/ref/struct2table.html#input_argument_namevalue_AsArray

'AsArray' — Indicator for how to treat scalar structure

false (default) | true | 0 | 1

true struct2table converts S to a table with one row and n variables. The variables can be different sizes.

false struct2table converts a scalar structure array with n fields into an m-by-n table. Each field must have m rows. This is the default behavior

[Peter Perkins]

The answer to "why is it designed that way" is that the majority of cases that involve converting a scalar struct to a table are cases where each field should be converted to a table variable. But you don't have a "scalar struct" in that sense, you have a "1x1 struct array". As Walter says, that's what the AsArray parameter is for.