Problem with using isfield

Dear all,

I have one structure with 4 fields and I would like to use function isfield for other work.

I have this part of code:

if isfield(shape,'leftLung',shape,'rightLung',shape,'spine');
    tmp2 = shape.spine{1};
    tmp3 = shape.leftLung{1};
    tmp4 = shape.rightLung{1};

and I have this error:

Error using isfield
Too many input arguments.

Error in Newmodel (line 115)
if isfield(shape,'leftLung',shape,'rightLung',shape,'spine');

Can you please advise me, how to change this part of code for good function? Thank you for your answers.

[Jan]

The shown code has no valid Matlab syntax. Therefore the readers cannot know its intention. Suggesting a wrong idea might be more confusing then useful for you.

Answer 1

[Thorsten]

if isfield(shape,'leftLung')
  tmp3 = shape.leftLung{1};
end
if isfield(shape, 'rightLung')
  tmp4 = shape.rightLung{1};
end
if isfield(shape,'spine');
  tmp2 = shape.spine{1};
end

[Steven Lord]

You're probably going to want to add else blocks to each of those if statements, to assign default values to tmp3, tmp4, and tmp2 if the shape struct doesn't contain fields by those names.

Answer 2

[Jan]

If you have a structure with 4 fields, checking the existing of fields is not necessary. I guess:

if isfield(shape,'leftLung') && isfield(shape,'rightLung') && isfield(shape,'spine')
  tmp2 = shape.spine{1};
  tmp3 = shape.leftLung{1};
  tmp4 = shape.rightLung{1};
end