Indexing and slicing in QMCL problem strings

[JosepVirgili]

Is there a way to slice and perform operations on the variables on the problem string.

I am looking for something similar to what is possible in CVXPY:
http://www.cvxpy.org/en/latest/tutorial/functions/index.html?highlight=slicing#indexing-and-slicing

I would like to add constraints that contain a norm of a subset of a variable. Something like:
norm(x[4:5],2)<=2

[echu]

I don't think there is, and that may have been a function of the ambiguity involved when a function is applied to, say, a sliced data matrix (sliced variables are straightforward). In the meantime, there's two approaches: If you need slicing, you have to declare a second variable and expand all the equations manually. For instance, Ax might become A1 x1 + A2 x2, where A = [A1 A2] and x = [x1; x2]. Another possibility is to declare a data matrix that does the slicing for you ( S=[0, 0; 0, 1] ) and use Sx where you need the slicing. Hope that helps!

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On Thu, Jun 29, 2017 at 11:40 AM Josep Virgili ***@***.***> wrote: Is there a way to slice and perform operations on the variables on the problem string. I am looking for something similar to what is possible in CVXPY: http://www.cvxpy.org/en/latest/tutorial/functions/index.html?highlight=slicing#indexing-and-slicing I would like to add constraints that contain a norm of a subset of a variable. Something like: norm(x[4:5],2)<=2 — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#56>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AADN0SyMo14OQgy8pEwDsum6agxmFxdRks5sI--2gaJpZM4OJtdX> .