Description for the "columns" arguments is missing

[michaelgrund]

Please describe what could be improved about this page or the typo/mistake that you found:

I would suggest to add a short note regarding the supported syntax for the columns option when using e.g. a data file as input, something like

• data (str or 2d array) – Either a data file name or a 2d numpy array with the tabular data. Use option columns (i) to choose which columns are x, y, color, and size, respectively (e.g. columns = [0, 1] if the x values are stored in the first column and y values in the second one, note: zero-based indexing is used).

I tried to fix that suggestion by my own following the instructions given in the Contributing Guidelines under Editing the Documentation, however, the corresponding .rst file is not available in the doc folder.

[seisman]

the corresponding .rst file is not available in the doc folder.

The documentation is automatically generated from the docstrings in the Python codes, see
https://github.com/GenericMappingTools/pygmt/blob/master/pygmt/base_plotting.py#L649

I would suggest to add a short note regarding the supported syntax for the columns option when using e.g. a data file as input, something like

data (str or 2d array) – Either a data file name or a 2d numpy array with the tabular data. Use option columns (i) to choose which columns are x, y, color, and size, respectively (e.g. columns = [0, 1] if the x values are stored in the first column and y values in the second one, note: zero-based indexing is used).

The description of the columns argument is missing. I think we should add an entry for the "columns" argument (like what for already have for zvalue, intensity), instead of explaining columns in the description of the data argument.

[michaelgrund]

opened a pull request with the suggested changes (according to your comment @seisman ).

[weiji14]

Reopening this because the "columns" description is missing for plot3d at https://www.pygmt.org/dev/api/generated/pygmt.Figure.plot3d.html.

I'm marking this as a good first issue as it should be easy enough to just copy and paste the "columns" description from https://github.com/GenericMappingTools/pygmt/blob/v0.3.0/pygmt/src/plot.py to https://github.com/GenericMappingTools/pygmt/blob/v0.3.0/pygmt/src/plot3d.py.

[seisman]

I'm not sure if we discussed it before (github search shows nothing). Is "columns" a good alias for -i option?

GMT provides both -i and -o, for selecting columns of input and output, respectively (see https://docs.generic-mapping-tools.org/latest/std-opts.html).

GMT uses incols and outcols for their long options (see https://github.com/GenericMappingTools/gmt/blob/master/src/gmt_common_longoptions.h).

Should we follow the GMT convention? If we choose columns for -i, what can we use for -o?

[weiji14]

I think the comment you're looking for is this:

Have we used the columns alias for -i elsewhere? It may be a bad choice, because GMT also has -o which controls columns of output.

In GenericMappingTools/gmt#230, GMT uses read-columns for -i and write-columns for -o.

GMT.jl uses incol for -i and outcol for -o.

Originally posted by @seisman in #666 (comment)

We kept columns as the alias for i because contour uses it too:

It is used in contour:

pygmt/pygmt/base_plotting.py

Line 576 in d3e131a

i="columns",

I can take this out though, since it's not as useful in the Python world where we can select columns using indexing.

Originally posted by @weiji14 in #666 (comment)

Since renaming the alias for i will be a backwards incompatible break, I would suggest holding #1040 off until v0.4.0 (or we can go ahead with it since the alias already exists, just that it's undocumented in the API docstring).

[seisman]

Great searching skills! 😃

Since renaming the alias for i will be a backwards incompatible break, I would suggest holding #1040 off until v0.4.0

Yes to me.

[willschlitzer]

Great searching skills! smiley

Since renaming the alias for i will be a backwards incompatible break, I would suggest holding #1040 off until v0.4.0

Yes to me.

Sounds good. I'll update the milestone on it.