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Tag Archives: webassembly

WebR IS HERE!

WebR 0.1.0 was released! I had been git-stalking George (the absolute genius who we all must thank for this) for a while and noticed the GH org and repos being updated earlier this week, So, I was already pretty excited.

It dropped today, and you can hit that link for all the details and other links.

I threw together a small demo to show how to get it up and running without worrying about fancy “npm projects” and the like.

View-source on that link, or look below for a very small (so, hopefully accessible) example of how to start working with WASM-ified R in a web context.

UPDATE:

Four more links:


<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>WebR Super Simple Demo</title>
<link rel="stylesheet" href="/style.css" type="text/css">
<style>
li {
  font-family:monospace;
}
.nospace {
  margin-bottom: 2px;
}
</style>
</head>
<body>
<div id="main">
<p>Simple demo to show the basics of calling the new WebR WASM!!!!</p>

<p><code>view-source</code> to see how the sausage is made</code></p>

<p class="nospace">Input a number, press "Call R" (when it is enabled) and magic will happen.</p>

<!-- We'll pull the value from here -->
<input type="text" id="x" value="10">

<!-- This button is disabled until WebR is loaded -->
<button disabled="" id="callr">Call R</button>

<!-- Output goes here -->
<div id="output"></div>

<!-- WebR is a module so you have to do this. -->
<!-- NOTE: Many browsers will not like it if `.mjs` files are served -->
<!-- with a content-type that isn't text/javascript  -->
<!-- Try renaming it from .mjs to .js if you hit that snag. -->

<script type="module">

  // https://github.com/r-wasm/webr/releases/download/v0.1.0/webr-0.1.0.tar.gz
  //
  // I was lazy and just left it in one directory

    import { WebR } from '/webr-d3-demo/webr.mjs'; // service workers == full path starting with /

    const webR = new WebR(); // get ready to Rumble 

  await webR.init(); // shot's fired

    console.log("WebR"); // just for me b/c I don't trust anything anymore

  // we call this function on the button press

    async function callR() {

        let x = document.getElementById('x').value.trim(); // get the value we input; be better than me and do validation
        console.log(`x = ${x}`) // as noted, i don't trust anything

    let result = await webR.evalR(`rnorm(${x},5,1)`); // call some R!
    let output = await result.toArray(); // make the result something JS can work with

        document.getElementById("output").replaceChildren() // clear out the <div> (this is ugly; be better than me)

    // d3 ops

        d3.select("#output").append("ul")

        const ul = d3.select("ul")

        ul.selectAll("li")
            .data(output)
            .enter()
            .append("li")
            .text(d => d)

    }

  // by the time we get here, WebR is ready, so we tell the button what to do and re-enable the button
    document.getElementById('callr').onclick = callR;
    document.getElementById('callr').disabled = false;


</script>

<!-- d/l from D3 site or here if you trust me -->
<script src="d3.min.js"></script>

</div>
</body>
</html>