how to reverse "grp2idx" back into original data

Hello, I have a categorical array of three categories: "S", "C", and "Q". I did "grp2idx()" in order to label each one of them (1,2,3) in order to do some operation, after which the new data (represented in 1,2,3) is different from the original one. I would now like to reverse the encoded vector back to a string vector. Is there any way to do so?

Answer 1

[Raghvi]

Hey Zeyad,

I am assuming your string vector was s. To get an index vector you would have run.

[g,gN,gL] = grp2idx(s); 

You can reproduce input argument s using the output gL:

gL(g(:,:)) 

You can also use gN(g) to reproduce the input argument s as a cell array of character vectors.

gN(g(:,:)) 

Checkout the examples in the documentation to know more about the conversions

https://www.mathworks.com/help/stats/grp2idx.html

[Zeyad Elreedy]

Oh, it works now. Thanks!