Display API naming standard

Display API naming standard#

Use the same words for the same display choices across QuantEM, quantem.gpu, quantem.widget, and their tutorials. Scientists should choose image size and layout without having to calculate figure dimensions or know the renderer. This is the target contract for new APIs and reviewed migrations; it does not mean that every existing function already accepts these keywords.

Common options#

Option	Meaning	Convention
`size`	Display size of each image panel	`"medium"` by default; `"small"`, `"medium"`, `"large"`, `"xlarge"`
`columns`	Images across a gallery	Usually specify this alone; derive rows automatically
`rows`	Images down a gallery	Optional alternative when row layout matters
`cmap`	Colormap	Use the existing scientific plotting name
`norm`	Display intensity transformation	Reuse the viewer’s supported normalization choices
`vmin`, `vmax`	Display contrast limits	In the documented image-value units; do not modify the data
`title`	Image or panel label	Preserve meaningful labels in saved images
`save`	Path for a static figure export	Optional convenience on APIs that support static export

These are shared names, not a requirement to add every option to every method. Only expose a control when the operation supports it. Keep scientific data saving distinct from exporting a display. Reuse existing viewers and return types; a naming cleanup does not justify a new wrapper or result class.

Size means one panel#

For Show2D and Show3D, the image-panel width targets are:

`size`	Panel width
`"small"`	300 CSS px
`"medium"`	450 CSS px
`"large"`	600 CSS px
`"xlarge"`	900 CSS px

The shared source is src/quantem/widget/panel_sizes.json, resolved by resolve_panel_width in src/quantem/widget/utils/ui.py. Use this resolver inside the widget package rather than adding a separate map to each viewer. Other packages should use their existing visualization layer; do not introduce a widget dependency into a computational backend just to import size constants.

Preserve aspect ratio. Two medium panels request two panel widths, plus their controls and spacing; medium does not mean 450 px for the entire gallery. Responsive layouts may shrink or wrap to fit the container. Keep font and control dimensions on the shared UI tokens rather than inventing proportional font sizes for each image preset.

Static views should use the same nominal per-panel targets through their visualization layer. Figure inches and DPI are renderer details: at a 100-DPI reference, 450 px corresponds to 4.5 inches. Titles, margins, export DPI and notebook scaling mean that figure dimensions alone do not guarantee a 450-px visible image. Check the rendered panel before claiming visual parity.

Beginner examples use size="medium", never require axsize=(6, 8) or figsize=(6, 8), and do not calculate inches, pixels or DPI in notebook cells. Existing precise publication-layout overrides can remain advanced options. Reject conflicting explicit overrides during a migration rather than silently discarding one; retain previously documented behavior until that migration.

Display size must not change the source data, reconstruction sampling, precision, fitting, or exported scientific arrays. Do not trade scientific quality for a smaller display. This standard does not change Show3DSlices, Show4DSTEM or ShowPtycho’s existing size behavior; those need separate review.

Rows and columns#

Use complete words, rows and columns, for new public layout controls. Avoid introducing nrows, ncols, num_cols or max_cols as another naming scheme for the same gallery operation. This does not rename scientific coordinates: array coordinates remain (row, col).

With columns=2, place up to two images across and calculate the required rows. Five images produce three rows, with one image in the last row.
With only rows=2, calculate the columns needed. Five images produce a two-row, three-column layout. Do not add rows to a simple helper unless users actually need this alternative.
With both explicitly supplied, validate that rows * columns can hold all images. Raise a helpful error if it cannot; never drop images silently.
Use row-major order. Do not create extra image panels just to fill unused slots. For a one-direction request, a smaller image count can use fewer rows or columns than requested.
Accept positive integers; reject booleans, zero, negatives and fractions. Invalid values should say how to correct the call, for example columns must be a positive integer; use columns=2.

New comparison galleries default to two columns with automatic rows. When an API supports both directions, distinguish omitted layout arguments from explicit ones internally so a default column count cannot conflict with an explicit rows request. Preserve legacy layout defaults during a naming-only migration unless a behavior change is separately approved.

Short calls first, detailed control when needed#

The detector helper supports this short call:

detector.show(data, size="medium", columns=2)

Its export options remain on the same method:

detector.show(
    data,
    size="large",
    columns=2,
    cmap="inferno",
    save="detector-images.png",
)

Advanced users can retain arrays with detector.bf, detector.df, detector.adf and detector.mean, then use the existing static or interactive viewer. Per-image colormaps and histogram limits belong to that viewer’s existing panel controls. Document whether contrast is linked across panels; do not add a parallel detector-specific histogram API.

Migration and review#

The library migration currently covers these entry points. Core QuantEM and tutorial updates remain separate work:

API	Existing surface	Migration direction
`detector.show`	`size`, `rows`, `columns`, `cmap`, `save`	Two columns by default
`detector_fit.show`	`size`, `cmap`, `save`; advanced `figsize`	Single plot; medium by default
`Show2D`	`size`, `columns`, `rows`; deprecated `ncols`	Preserve three-column default and saved state
`Show3D`	`size`, `columns`, `rows`; deprecated `max_cols`	Preserve four-column default, legacy zero and saved state
Core `show_2d`	Nested arrays, `axsize`, optional `figsize`	Add named size and optional layout through the existing function
SSB focus and trial galleries	`size`, `columns`, `rows`; focus retains deprecated `max_cols`	Named per-panel size; keep fitted arrays unchanged
SSB result and rotation views	`size`, `cmap`, `save`; advanced `axsize`	Rows/columns for galleries; fixed rotation/comparison layout

For a published API, support old keywords for a documented transition, emit deprecation warnings, and reject calls supplying both old and new aliases. Keep both paths on one implementation. Unreleased APIs without external users can be renamed directly. Do not change a serialized recipe without a migration path.

Before updating a tutorial, verify the installed signature supports its calls. Update docstrings, examples, errors and relevant agent guidance together. Test old/new keyword parity, defaults, invalid values, partial last rows and saved output. Verify representative static and interactive layouts, including a narrow viewport, and confirm display options leave scientific arrays intact. Keep design documentation distinct from evidence of a completed runtime change.

Detector and SSB display options#

Use detector_fit.show(size="medium", cmap="inferno", save="detector-fit.png") for the fitted detector disk. It has one panel, so no rows/columns controls. Use the same keywords on detector.show(data, columns=2) for the detector gallery.

ssb.show("parameters", rows=2, cmap="viridis", save="fit.png") lays out the two static fit landscapes. Focus views accept size, rows, columns and cmap in both Show2D/Show3D and static mode. Export with ssb.show("focus", mode="static", save="focus.png"); native image density is retained. save exports the figure, while ShowPtycho save_dir stores scientific calibration. Plain ssb.show() retains ShowPtycho’s responsive layout and its existing Color control.

Automatic output sampling#

Auto chooses 1×, 2×, 3× or 4× from the acquisition calibration, with a maximum of 4×. Select 8× explicitly with ssb.show(upsampling=8) or the ShowPtycho Upsampling menu. For a standalone reconstruction, use ssb.reconstruct(fit, upsampling_factor=8).

The nominal bandwidth requirement remains separate from the selected grid. When Auto is capped, the fit report and viewer settings identify the larger requirement; a 4× grid does not imply full nominal bandwidth. Fitting and source data are unchanged. Saved Auto fits reopen under the current cap; saved explicit 8× choices retain 8×.