Masks and strings in the Engee Function

In Engee, you can add a simple user interface to a block. This is called block masking. Masks can be used to hide the internal structure of the unit from the user. This is a great technique, and let's add a mask to the Engee Function block from last post.

The EF_pdist2 function that we used has an optional parameter, the calculation mode (metric). During the project, we will give the user the opportunity to control it through a mask.

Let's remember what the module code looks like.:

How do I pass a string from a mask to an Engee Function?

Before masking the Engee Function, it is necessary to consider a functional limitation - the Engee Function cannot work with type parameters. String. But the calculation method is set by a string. Therefore, we need to encode the selected method with a certain number, pass this number as a parameter to the Engee Function, and then decode it. In other words, the mask will need not one parameter, but two. Then you can implement such a scheme:

We will decode the calculation mode using a dictionary, since the Dict data type implements a collection of key-value pairs. In this case, the key can be any base type. Therefore, it is possible to make even such a dictionary.:

mode_dict_t = Dict(1=>"euclidean",2=>"squaredeuclidean",3=>"manhattan",4=>"cosine")

It can be seen that the key here is an integer, and the value is a string. This allows us to do the following:

Now let's take a look at the code of the Engee Function block methods.:

include("/user/start/examples/base_simulation/advanced_block_masking/PDIST2.jl")

mutable struct Block <: AbstractCausalComponent
	cache::Matrix{Float64};
	modeC::Int64
	function Block()
    		c = zeros(Float64,INPUT_SIGNAL_ATTRIBUTES[1].dimensions);
    		info("Allocated $(Base.summarysize(c)) bytes for pdist2")
    		info("Selected $(PDIST2.mode_dict_t[mode])")
    		new(c,mode)
	end
end

function (c::Block)(t::Real, in1, in2)
    try
        c.cache = PDIST2.EF_pdist2(in1,in2;metric=PDIST2.mode_dict_t[c.modeC]);
    catch
        error("Matrix Dimensions should be equal!")
        stop_simulation()
    end

    return c.cache
end

modeC is a parameter that takes the value of a numeric variable from a mask (see ). Thus, we can pass the calculation method to our PDIST2 function as

PDIST2.mode_dict_t[c.modeC]

And we will get the number by calling back the "real" parameter from the drop-down list.:

if mask.parameters.mask_mode.value == "euclidean"
    mask.parameters.mask_mode_int.value = 1;
elseif mask.parameters.mask_mode.value == "squaredeuclidean"
    mask.parameters.mask_mode_int.value = 2;
elseif mask.parameters.mask_mode.value == "manhattan"
    mask.parameters.mask_mode_int.value = 3;
elseif mask.parameters.mask_mode.value == "cosine"
    mask.parameters.mask_mode_int.value = 4;
end

So the mask will look like this:

Note that the mask_mode_int parameter must be computable. And it's hidden because we don't want to let the user break anything.

Finally, we will open and run the final model in all modes.:

Conclusions

During the project, we learned how to drop string parameters into the Engee Function, and also used dictionaries in a standard, albeit unobvious way.