Feature #1008: square function - CoCoALib - CoCoA Project

Feature #1008

square function

Added by John Abbott about 7 years ago. Updated almost 7 years ago.

Status:

Closed

Priority:

Normal

Assignee:

John Abbott

Category:

New Function

Target version:

CoCoALib-0.99550 spring 2017

Start date:

12 Feb 2017

Due date:

% Done:

100%

Estimated time:

1.01 h

Spent time:

0.75 h

Description

In utils.H there is a fn called square defined only for double. It used only in ApproxPts.C.

I am sure that it is inappropriate to have that fn, so have moved it to ApproxPts.C.

Do we want to have a square function?

Related issues

History

#1 Updated by John Abbott about 7 years ago

A search for square showed that there had been a square function for RingElem, but that it was removed (presumably with the idea that a user should call power with second arg equal to 2). I note that the fn square for RingElem called a special member fn mySquare (which may sometimes be faster than myMul on two copies of the arg).

If we do put a general square fn somewhere, it should probably be a template fn:

template <typename T>
T square(const T& a)
{ return a*a; }

However, this defn would not use the mem fn RingBase::mySquare.

#2 Updated by John Abbott about 7 years ago

Status changed from New to In Progress
% Done changed from 0 to 10

So far we have not really felt the need for a square function in CoCoALib (presumably).

So maybe it does not make much sense to create one... yet another function for the user to learn!

Is square(x) that much easier to read/comprehend than power(x,2)?

#3 Updated by Anna Maria Bigatti about 7 years ago

If we had a square we should document how it differs from power(x,2). So I think we'd better not.
If we have mySquare, that should be called by power(x,2).

In short: mySquare make sense, square does not (IMHO)