stdlib. Add optional arguments to savetxt

[fiolj]

Hello, I've been away from the project for a long time, and could not find discussions over some features of savetxt that I find useful, following mostly numpy savetxt behavior. I'd like to change the interface to something like. Please let me know
if there is any interest. As I said I could not find if it already was discussed and discarded.

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savetxt - save a 2D array into a text file

Status

Experimental

Description

Saves a rank-2 array into a text file.

Syntax

call [[stdlib_io(module):savetxt(interface)]] (array [, filename | unit] [, delimiter] [, fmt] [, comments] [, header])

Arguments

array: Shall be a rank-2 array of type real, complex or integer.

filename or unit: Shall be either a character expression containing the name of the file or an integer containing the unit of an already open file, that will contain the 2D array. Setting the two of them shall give an error

delimiter (optional): Shall be a character expression of any length that contains the delimiter used to separate the columns. The default is a single space ' '.

fmt: (optional): Fortran format specifier for the text save. Defaults to the write format for the data type.

header: (optional) Shall be a character expression that will be written at the beginning of the file.

footer: (optional) Shall be a character expression that will be written at the end of the file.

comments: (optional) : Shall be a character expression of(length 1 that will be prepended to the header and footer strings to mark them as comments. Default: # .

Output

Provides a text file called filename that contains the rank-2 array.

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Rationale

Antecedents

• Python's Numpy

• I have a similar function

Discussion

1. Adding the possibility of providing a unit number in place of a filename gives flexibility to add partial tables to a file.
2. fmt Gives the possibility of customize the output. In many cases complex calculations give only a few significant figures and I would like the number saved to express that.
3. header and footer give the possibility to add information to the data files (column names, information on parameters used in calculations or measurements, etc).
4. Following numpy I find extremely useful if non-data information is commented or signaled in some form. This would be the use of the argument comment.