what does 1x8 struct mean?

what does the notation of size for struct means ? e.g. 1x8 struct with 3 fields

Answer 1

[dpb]

It's an array of structures oriented as a row vector of those structures, each entry of which has three fields. Simple example is structure returned by dir...

>> d=dir('*.csv')  % get a directory structure for local .csv files...
d = 
31x1 struct array with fields:
  name
  date
  bytes
  isdir
  datenum
>> d=d.'  % turn it from column- to row-oriented (not that it really makes much difference)
d = 
1x31 struct array with fields:
  name
  date
  bytes
  isdir
  datenum
>> d(23).name  % address a particular entry and field in the array 
ans =
long.csv
>>

Answer 2

[Orion]

You can see it as an array of structure.

if you define a structure such as

s.a = 1;
s.b = 2;

s is actually a 1x1 struct. you can access the fields either with the syntax s.a or s(1).a .

but you can create an array of structure :

s(1).a = 1;
s(1).b = 2;

s(2).a = 3;
s(2).b = 4;

Now s is a 1x2 struct. you can access the 'a' field of the ith component withe syntax s(i).a