69 lines
1.2 KiB
JavaScript
69 lines
1.2 KiB
JavaScript
export async function loadMNIST( device, sampleCount = 1000, preloader ) {
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async function loadFile( path, progress ) {
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const res = await fetch( path );
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const buffer = await res.arrayBuffer();
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if ( preloader ) {
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preloader.setProgress( progress );
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}
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return new Uint8Array( buffer );
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}
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if ( preloader ) preloader.setText( "Loading MNIST images…" );
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const imgRaw = await loadFile(
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"./models/train-images-idx3-ubyte",
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40
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);
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if ( preloader ) preloader.setText( "Loading MNIST labels…" );
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const lblRaw = await loadFile(
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"./models/train-labels-idx1-ubyte",
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60
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);
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const header = 16;
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const fullCount = lblRaw.length - 8;
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const count = Math.min( sampleCount, fullCount );
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const images = new Float32Array( count * 28 * 28 );
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const labels = new Uint32Array( count );
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for ( let i = 0; i < count; i++ ) {
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labels[ i ] = lblRaw[ 8 + i ];
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const src = header + i * 784;
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const dst = i * 784;
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for ( let j = 0; j < 784; j++ ) {
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images[ dst + j ] = imgRaw[ src + j ] / 255;
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}
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if ( preloader && ( i % 64 === 0 ) ) {
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preloader.setProgress(
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60 + ( i / count ) * 40
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);
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}
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}
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if ( preloader ) {
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preloader.setProgress( 100 );
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}
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return { images, labels, count };
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}
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