How to avoid repeating load data from a function

dear all,

I have a function that will be call 1000 times. In that function, there are several "load" sentence to load some data. And I have another function to call this function 1000times. The data will be loaded 1000 times. If I put the load to the outside function, actually the data will not go into the inside function. How can I just load once and loop the function 1000 times?

Answer 1

[Walter Roberson]

Shared variables with a nested routine; or pass the values in to the routine.

Note that shared variables must be initialized (to any value) before the nested routine is declared.

function ndemo
  foo = [];  %okay to share
  bar = [];  %okay to share
  function nested
    biz = foo + bar;  %okay, references previously-declared vars
    baz = biff;       %not okay, this will not exist until run time
  end
  biff = [];          %not okay to share with "nested"
  load fingle.mat;    %load values for foo and bar and biff
  [foo, bar, biff]    %will show the loaded values
  nested();           %will error saying biff was unknown
end

To emphasize: it isn't enough for the value of a variable to be known at execution time in order for it to be shared with a nested function: the variable has to have been given some visible value before the nested routine was declared, not before it was executed.

[Yang]

Thanks for suggestions. But my function is an outside standalone function and I'm not going to add it as a nested function inside another function.

This is my function that to be looped:

function select = recognition( f )

%RECONGNITE Summary of this function goes here

% Detailed explanation goes here

load characters.mat;

load cluster_record2.mat;

load space_variance.mat;

load feature.mat;

load mean_variance.mat;

load level_number.mat;

......

end

and another function to call this function. If I put load sentences in the outside function, data will not pass into the called function.

[Walter Roberson]

Then I suggest using "persistent".

persistent characters

persistent space_variance

and so on. Then have a test such as

if isempty(characters)

load characters.mat;

load cluster_record2.mat;

load space_variance.mat;

%etc

end

This will only do the load if the data has not already been loaded.