Why was the name "arange" chosen for the numpy function?

Question

Is there a specific reason the numpy function arange was named so?

People habitually make the typo arrange, assuming it is spelled as the English word, so the choice seems like something of an oversight given that other less ambiguously spelled options (range etc) are unused by numpy.

Was it chosen as a portmanteau of array and range?

Disordered

Travis alludes to it in his 2006 book, web.mit.edu/dvp/Public/numpybook.pdf, Quote: "Function similar to Python’s built-in range() function except it returns an ndarray object" – Eboni

Shadowing range when importing numpy with * would a nuisance. sum and min are shadowed, but with fewer issues. For example, for i in range(10): is preferable to for i in arange(10):. – Eboni

Answer 1

NumPy derives from an older python library called Numeric (in fact, the first array object built for python). The arange function dates back to this library, and its etymology is detailed in its manual:

arrayrange()

The arrayrange() function is similar to the range() function in Python, except that it returns an array as opposed to a list.

...

arange() is a shorthand for arrayrange().

• Numeric Manual
  2001 (p. 18-19), 1999 (p.23)

Tellingly, there is another example with array(range(25)) (p.16), which is functionally the same as arrayrange().

Disordered

And linspace is for linearly space(vs geomspace and logspace)? – Softy

Answer 2

It is explicitly modelled on the Python range function. The precedent for prefixing a was that in Python 1 there was already a variant of range called xrange.

Inquest

Though I wouldn't surprised if arange preceeds xrange. Any idea when xrange was added to Py2? – Eboni

@hpaulj, Looking at python.org/doc/versions, it seems to have been added in python2.0, in October 2000. – Exceptionable

xrange was in Python 1.5.2 (1998). Maybe earlier, but that would have been before my time. – Inquest

xrange has been in python since at least as far back as 1.4 (25 October 1996) docs.python.org/release/1.4/lib/node26.html – Disordered