@fxpineau/moc-wasm NPM

`moc-wasm`

WebAssembly Library to read/write/create/manipulate HEALPix Multi-Order Coverage maps (MOCs) in a web page.

About

This wasm library is made from the Rust MOC library. It implements the v2.0 of the MOC standard, including (S-)MOCs, T-MOCs and ST-MOCs.

If you are developing a web page using:

JavaScript: you can use this library (see next section for the list of available JS functions);
Rust --> wasm: the code can be an example of how to directly use the Rust MOC library.

Technically, this project relies on wasm-bindgen: a big thank you to the developers.

For tools able to display MOCs, see:

the Aladin Desktop sky atlas in Java (also supports MOC operations)
the Aladin Lite, "a lightweight version of the Aladin Sky Atlas running in the browser".
MOCPy, a python wrapper using the very same Rust MOC library.

Use it

Try it

From version 0.7.0: from this demo page.
Older versions (pre v0.7.0): from this demo page.

Put it in your own Web page

Download the last moc-wasm-vxx.tar.gz from thegithub release page. Put it in the same directory of you web page and decompress it:

tar xvzf moc-wasm-vxx.tar.gz

And add this in your HTML body:

<script type="module">
    import init, * as moc from './pkg/moc.js';
    async function run() {
        const wasm = await init().catch(console.error);
	window.moc = moc;
    }
    run();
</script>

This the example page.

Used by

Example of web page(s) using MOCwasm:

Gravitational-Wave Sky Localizations

Use it in you project with NPM

See the npm moc-wasm package. (Not tested, we need feedbacks!).

Available JavaScript methods (from v0.7.0)

Following the provided index.html example, use the moc prefix to, call the following objects/methods (e.g. moc.debugOn() or moc.MOC):

# In case of failure, enable Rust stack trace
debugOn();

# Available objects
MOC
TMOC
FMOC
STMOC

# You can then explore the various methods each object has,
# a large part are common, creation methods from parameters are specific

# - fires the select file dialog (see JS file for more details) to load a local MOCs
let mymoc = (T|F|ST)MOC.fromLocalFile()
# - load the MOC from a FITS file content, provided in the UInt8Array
let mymoc = (T|F|ST)MOC.fromFits(data: UInt8Array)
# - load the MOC stored in a FITS file of given URL
let mymoc = (T|F|ST)MOC.fromFitsUrl(url) // A string of supported mime types can be passed in an additional last parameter
# - load from a ASCII String or an ASCII file
let mymoc = (T|F|ST)MOC.fromAscii(data: String)
let mymoc = (T|F|ST)MOC.fromAsciiUrl(url)

# - load from a JSON String or a JSON file
let mymoc = (T|F|ST)MOC.fromJson(data: String)
let mymoc = (T|F|ST)MOC.fromJsonUrl(url)


# - fires the select dialogto load a multi-order map FITS file and create a MOC from the given parameters
let mymoc = MOC.fromLocalMultiOrderMap(from_threshold: f64, to_threshold: f64, asc: bool, not_strict: bool, split: bool, revese_recursive_descent: bool)
# - load a multi-order map FITS file and create a MOC from the given parameters
let mymoc = MOC.fromFitsMulitOrderMap(data: UInt8Array, from_threshold: f64, to_threshold: f64, asc: bool, not_strict: bool, split: bool, revese_recursive_descent: bool)
# - load a multi-order map FITS file of given URL and create a MOC from the given parameters
let mymoc = MOC.fromMultiOrderMapFitsUrl(url, from_threshold: f64, to_threshold: f64, asc: bool, not_strict: bool, split: bool, revese_recursive_descent: bool) // A string of supported mime types can be passed in an additional last parameter

# Save a MOC
# - get the FITS binary representation of the MOC
mymoc.toFits() -> Uint8Array
# - get the ASCII representation of the MOC
toAscii(name, fold: null|int) -> String
# - get the JSON representation of the MOC
mymoc.toJson(fold: null|int) -> String
# - fires the download dialog to save the MOC in an ASCII/JSON or FITS file.
mymoc.toFitsFile()
mymoc.toAsciiFile(fold: null|int)
mymoc.toJsonFile(fold: null|int)

# Create MOC
# - create a S-MOC from a geometric shape
let mymoc = MOC.fromCone(depth, lon_deg, lat_deg, radius_deg)
let mymoc = MOC.fromRing(depth, lon_deg, lat_deg, internal_radius_deg, external_radius_deg)
let mymoc = MOC.fromEllipse(depth, lon_deg, lat_deg, a_deg, b_deg, pa_deg)
let mymoc = MOC.fromZone(depth, lon_deg_min, lat_deg_min, lon_deg_max, lat_deg_max)
let mymoc = MOC.fromBox(depth, lon_deg, lat_deg, a_deg, b_deg, pa_deg)
let mymoc = MOC.fromPolygon(depth, vertices_deg: Float64Array, complement: boolean)
# - create a S-MOC from a list of coordinates
let mymoc = MOC.fromCoo(depth, coos_deg: Float64Array)
# - create a T-MOC from a list of Julian Days
let mymoc = MOC.fromDecimalJDs(depth, jd: Float64Array)
# - create a T-MOC from a list of Juliand Days range
let mymoc = MOC.fromDecimalJDRanges(depth, jd_ranges: Float64Array)
# - reate a new S-MOC from the given lists of UNIQ and Values (i.e. from a Multi-Order Map)
let mymoc = MOC.fromValuedCells(depth,  density: bool, from_threshold: f64, to_threshold: f64, asc: bool,  not_strict: bool, split: bool, revese_recursive_descent: bool, uniqs: Float64Array, values: Float64Array)

# Single MOC operations
# S/T-MOC
let mynewmoc = mymoc.not() // or mymoc.complement()
let mynewmoc = mymoc.degrade(depth)
# - S-MOC only
let mynewmoc = mymoc.extend()
let mynewmoc = mymoc.contract()
let mynewmoc = mymoc.externalBorder()
let mynewmoc = mymoc.internalBorder()
# -- split considering the 4 direct neighbours (NE, NW, SE, SW) as being part of the same region
let n = mymoc.splitCount()
let mysubmocs = mymoc.split()
# -- split considering the 4 direct neighbours (NE, NW, SE, SW) plus the 4 indirect neighbours (S, N, E, W) as being part of the same region
let n = mymoc.splitIndirectCount()
let mysubmocs = mymoc.splitIndirect()

# Two MOCs operations
let union = mymoc1.or(mymoc2) // or  mymoc1.union(mymoc2)
let inter = mymoc1.and(mymoc2) // or  mymoc1.intersection(mymoc2)
let symdi = mymoc1.xor(mymoc2) // or  mymoc1.symmetric_difference(mymoc2)
let diffe = mymoc1.minus(mymoc2) // or  mymoc1.difference(mymoc2)

# Operation on ST-MOC
let mysmoc = mystmoc.timeFold(mytmoc)
let mytmoc = mystmoc.spaceFold(mysmoc)

# Filter operations (return arrays containing 0 (out of the MOC) or 1 (in the MOC))
let boolarray = mysmoc.filterCoos(coos_deg: Float64Array)
let boolarray = mytmoc.filterJDs( jds: Float64Array)

Example 1: 2MASS and SDSS DR12 MOCs

In the index.html web page put behind a server (see next section), simply copy/paste those line the web browser console:

  // Load 2MASS and SDSS DR12 MOCs from CDS
  let moc2mass = await moc.MOC.fromFitsUrl('http://alasky.u-strasbg.fr/footprints/tables/vizier/II_246_out/MOC');
  console.log("2MASS MOC depth: " + moc2mass.getDepth());
  console.log("2MASS MOC coverage: " + moc2mass.coveragePercentage() + "%");
  let mocsdss = await moc.MOC.fromFitsUrl('http://alasky.u-strasbg.fr/footprints/tables/vizier/V_147_sdss12/MOC');
  console.log("SDSS DR12 MOC depth: " + mocsdss.getDepth());
  console.log("SDSS DR12 MOC coverage: " + mocsdss.coveragePercentage() + "%");

  // Init a timer
  console.time('timer');
  // Performs MOC intersection
  let tmass_inter_sdss12 = moc2mass.and(mocsdss);
  // Log time
  console.timeLog('timer', 'Intersection');
  // Performs MOC union
  let tmass_union_sdss12 = moc2mass.or(mocsdss);
  // Log time
  console.timeLog('timer', 'Union');
  // Degrade to order 2 the result of the intersection
  let tmass_union_sdss12_d2 = tmass_union_sdss12.degrade(2);
  // Remove timer
  console.timeEnd('timer');

  console.log("(2MASS AND SDSS DR12) MOC depth: " + tmass_inter_sdss12.getDepth());
  console.log("(2MASS AND SDSS DR12) MOC coverage: " + tmass_inter_sdss12.coveragePercentage() + "%");
  console.log("(2MASS OR SDSS DR12) MOC depth: " + tmass_union_sdss12.getDepth());
  console.log("(2MASS OR SDSS DR12) MOC coverage: " + tmass_union_sdss12.coveragePercentage() + "%");
  console.log("(2MASS OR SDSS DR12) MOC coverage at depth 2: " + tmass_union_sdss12_d2.coveragePercentage() + "%");

  // Print the ASCII and JSON serializations of '2mass_inter_sdss12_d2'
  console.log(tmass_inter_sdss12.toAscii());
  console.log(tmass_inter_sdss12.toJson());

  // Save the result of the intersection in a FITS file
  tmass_inter_sdss12.toFitsFile();

Example 2: Build a MOC from a Multi-Order Map and split it into disjoint MOCs

  // Load a multi-order map and create a MOC on-the-fly
  let lalmap = await moc.MOC.fromMultiOrderMapFitsUrl('http://cdsxmatch.u-strasbg.fr/lab/moc/LALInference.multiorder.fits', 0.0, 0.9, false, false, false, false);

  console.log("LALMAP MOC depth: " + lalmap.getDepth());
  console.log("LALMAP MOC coverage: " + lalmap.coveragePercentage() + "%");

  // Init a timer
  console.time('timer');

  // Count the number of disjoint MOCs in the MOC
  let n = lalmap.splitCount();
  console.log("n sub_mocs: " + n);
  console.timeLog('timer', 'Spit count');

  // Do split the MOC in 10 sub-MOCs
  let mocs = lalmap.split();
  console.timeLog('timer', 'Spit');
  // Remove timer
  console.timeEnd('timer');

  // List MOCs loaded in the page
  console.log(mocs);

  // Get info on sub-MOCs
  for (let i = 0; i < mocs.length; i++) {
    console.log("Coverage percentage sub " + i  + ": " + mocs[i].coveragePercentage());
  }

Install/run locally

Checkout the git project.

Install rust (check that ~/.cargo/bin/ is in your path), or update the Rust compiler with:

rustup update

Install the wasm32-unknown-unknown toolchain (done automatically with wasm-pack?):

rustup target add wasm32-unknown-unknown

Install wasm-pack following those instructions or using (automatic download of sources and local compilation):

cargo install wasm-pack

Run tests:

wasm-pack test --node

Build the project, see wasm-bindgen doc

wasm-pack build --out-name moc --target web --no-typescript 
wasm-pack build --out-name moc --target web --no-typescript --release

Run a local server

either using the static server from https://crates.io/crates/https

http

or use python

python2 -m SimpleHTTPServer
python3 -m http.server

And load the web page http://0.0.0.0:8000/ in our favorite (firefox?) web browser.

Publish on NPM (self reminder)

See here

wasm-pack build --out-name moc --release --scope fxpineau
wasm-pack login
wasm-pack publish

ToDo list

Add to_png or to_image for S-MOCs
Implement difference (xor) for ST-MOCs
Implement complement (not) for ST-MOCs (complement on Space only or also on Time with allsky S-MOCs?)
Implement degradeSpace (?), degradeTime (?), degradeSpaceAndTime (?) for ST-MOCs
Build a ST-MOCs from an array of (jd, lon, lat)
Add possibility to filter an array of (jd, lon, lat) with a ST-MOCs
Add overlap/contains(MOC, MOC) methods? (use cases?)
(Internal change for performances) add native operations on RangeMOC2 instead of transforming in TimeSpaceMoc
Implement an egui interface

License

Like most projects in Rust, this project is licensed under either of

Apache License, Version 2.0, (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this project by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Acknowledgements

This work has been supported by the ESCAPE project.
ESCAPE - The European Science Cluster of Astronomy & Particle Physics ESFRI Research Infrastructures - has received funding from the European Union’s Horizon 2020 research and innovation programme under Grant Agreement no. 824064.

healpix moc

@everything-registry/sub-chunk-349

0.9.1

5 months ago

0.8.0

12 months ago

0.7.0

2 years ago