gca — Return the handle for the current axes, or a struct describing the active axes state.

gca returns the encoded handle for the current axes. RunMat also supports a 'struct' mode that returns a small struct snapshot describing the active figure, subplot grid, and selected axes index.

How gca works

• gca() returns a scalar numeric axes handle.
• gca('struct') returns a struct with fields handle, figure, rows, cols, and index.
• The current axes reflect the active subplot when subplot has been used.
• Unsupported arguments raise gca plotting errors.

How RunMat runs gca on the GPU

gca performs no provider dispatch; it only reads the active axes state from the plotting registry.

GPU memory and residency

gca returns host-side handles or structs and does not interact with GPU residency.

Examples

Read the current axes handle

figure(1);
ax = gca()

Expected output:

% ax is a numeric axes handle

Inspect the active subplot layout

subplot(2, 2, 3);
info = gca("struct")

Expected output:

info =
  struct with fields:
    handle
    figure
    rows
    cols
    index

FAQ

What is special about gca('struct')?

It is a RunMat extension that returns a struct snapshot of the active axes state instead of just the encoded numeric handle.

Does gca reflect subplot selection?

Yes. When a subplot is active, gca reports that subplot's axes handle and metadata.

Does gca run on the GPU?

No. It only reads host-side plotting state.

Related Plotting functions

Open-source implementation

Unlike proprietary runtimes, every RunMat function is open-source. Read exactly how gca works, line by line, in Rust.

• View gca.rs on GitHub
• Learn how the runtime works
• Found a bug? Open an issue with a minimal reproduction.

About RunMat

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