"matfile" function does not fetch variables with multiple fields?

I have a very big mat file(about 2 GB),in which there are several hierarchical relationships, there is an array of variables occupy a lot of memory, such as matObj.field.sub1.sub2.var, in the "var" occupies a lot of space, it is not convenient to import into matlab at once, so I use the matfile function to parse, size function to determine the size of var, I tried to use size( matObj,'field.sub1.sub2.var') to judge, but it will report an error, field.sub1.sub2.var is not a variable of matObj. How can I solve the problem efficiently? I'd appreciate your answer!

Answer 1

[Walter Roberson]

You cannot. Only entire variables can be inquired about. You would have to load the variable to determine the size of the field.

I suggest that you store the sizes into a variable at the time you write the data into the file.

[xingxingcui]

Not the best way, but thanks for your answer.