Loading variables to a specifc workspace

I am trying to use the load command to load some variables into my workspace.

because the load command is used inside a function call, it is loading the data to the workspace of the function and not loading it to my base for example.

How can i use the load command to load variables to a specific workspace

Answer 1

[Star Strider]

One option to transfer specific variables to your script (calling) workspace would be to include them as outputs of your function.

You could of course load them into your workspace with a separate load call.

[Robert Scott]

I dont know why you always answer a question that is not asked.

There is a reason im loading a workspace because it contains hundreds of variables.

You did this on my last quesiton also.

[Star Strider]

The impression I got initially (and on re-reading your question now) is that you are loading data within a function (so they load only into the function workspace) and want to load some or all of those variables into your base workspace as well. Incluidng those variables (as a structure, cell array, or individually) as outputs of your function would transfer them to your base workspace.

If that is not the question you are actually asking, please clarify it.

[Robert Scott]

That is correct, however, i cannot make 500 variables all output arguments of a function.

[Star Strider]

Creating them as one argument involves putting them in a structure or cell array or a numeric array, depending on what they are. (Structures and cell arrays can hold different classes of variables.) Then evaluate them in your base workspace by referring to them as parts of that one variable, using the usual structure or cell array or numeric array indexing or structure references. I do this frequently, with both input arguments and outputs of functions. It is easier and more efficient than passing long lists of individual variables.

With respect to using load, for example with a .mat file, if you load into a variable, that variable becomes a structure with all the variables in the .mat file referred to within it. So all that is necessary is to pass that structure as an output. All its contents will be available in your base workspace, providing the call to your function includes that element of the outputs as a requested output.

[Steven Lord]

I'm not 100% certain off the top of my head what the upper limit on the number of output arguments you can return from a function, but even if that limit is greater than 500 I agree with your premise that you should not return 500 outputs from a function.

Instead, pack the pieces of data that you want to return from the function into a container: a struct array, a table, a cell array, an object, or even a dictionary array. Then return that container, with the data organized inside it, from your function.

[Walter Roberson]

Assign the result of load() to a variable; the result will be a struct with one field for each variable name. Pass out the struct.

If you are loading multiple files in the same routine, then I start to be concerned about the possibility that the same variable might exist in more than one file, and what the desired behaviour is in that situation.

Answer 2

[Walter Roberson]

How can i use the load command to load variables to a specific workspace

MATLAB does not provide any way to do that.

I would provide work-arounds, but you made it clear to Star Strider that you only want answers to questions that you actually asked, rather than solutions that would solve the challenge you are facing.

Answer 3

[Steven Lord]

How can i use the load command to load variables to a specific workspace

In general, you cannot do exactly what you asked. There's no functionality to say "load variables into the workspace of the function call at level 3 of the current calling stack", for instance.

You could do what you described actually wanting to do in your comment on Star Strider's answer, but I strongly discourage it. The assignin function allows you to assign values to variables in the workspace of the current stack frame's caller or in the base workspace.

However, it sounds like you're planning to load an arbitrary number of arbitrarily named variables into that workspace and "poofing" variables like that is a Bad Idea. If you do that there is no safeguard against overwriting existing variables with the same name as variables in your base workspace. If your program then "reaches" into that workspace to access that data and the data isn't what you expected, trying to debug whatever happens could be difficult and/or time consuming to diagnose where the bug in your code originated. This is especially true if you were to load multiple files that way -- which of those files had the variable with the errant value?

Creating hundreds of variables in the base workspace also makes it more difficult to find the data you actually need or want to access.