How to use the d3-interpolate.interpolateZoom function in d3-interpolate

iRGBColorObj = d3Interpolate.interpolateObject(d3Color.rgb('steelblue'), d3Color.rgb('seagreen'));
objRGBColor = iRGBColorObj(0.5);

// test interpolateTransformCss(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateTransformCss('rotate(0deg)', 'rotate(60deg)');
str = iString(0.5);

// test interpolateTransformSvg(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateTransformSvg('rotate(0)', 'rotate(60)');
str = iString(0.5);

// test interpolateZoom(a, b) signature ----------------------------------------------------

iZoom = d3Interpolate.interpolateZoom([50, 50, 300], [100, 100, 500]);
zoom = iZoom(0.5);

console.log('Recommended transition duration = %d', iZoom.duration);

// test quantize(interpolator, n) signature ------------------------------------------------

arrNum = d3Interpolate.quantize(d3Interpolate.interpolateRound(-1, 2), 4); // infered template parameter type
arrStr = d3Interpolate.quantize(d3Interpolate.interpolateString('-1', '2'), 4); // explicit template parameter typing

// arrStr = d3Interpolate.quantize(d3Interpolate.interpolateRound(-1, 2), 4); // test fails, due to explicit typing v argument type mismatch

// test interpolateRgb(a, b) signatures ----------------------------------------------------------------

// without gamma correction
iString = d3Interpolate.interpolateRgb('seagreen', 'steelblue');
iString = d3Interpolate.interpolateRgb(d3Color.rgb('seagreen'), d3Color.hcl('steelblue'));

objRGBColor = iRGBColorObj(0.5);

// test interpolateTransformCss(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateTransformCss('rotate(0deg)', 'rotate(60deg)');
str = iString(0.5);

// test interpolateTransformSvg(a, b) signature ----------------------------------------------------

iString = d3Interpolate.interpolateTransformSvg('rotate(0)', 'rotate(60)');
str = iString(0.5);


// test interpolateZoom(a, b) signature ----------------------------------------------------

iZoom = d3Interpolate.interpolateZoom([50, 50, 300], [100, 100, 500]);
zoom = iZoom(0.5);

console.log('Recommended transition duration = %d', iZoom.duration);

// test quantize(interpolator, n) signature ------------------------------------------------

arrNum = d3Interpolate.quantize(d3Interpolate.interpolateRound(-1, 2), 4); // infered template parameter type
arrStr = d3Interpolate.quantize(d3Interpolate.interpolateString('-1', '2'), 4); // explicit template parameter typing

// arrStr = d3Interpolate.quantize(d3Interpolate.interpolateRound(-1, 2), 4); // test fails, due to explicit typing v argument type mismatch

// test interpolateRgb(a, b) signatures ----------------------------------------------------------------

// without gamma correction
iString = d3Interpolate.interpolateRgb('seagreen', 'steelblue');
iString = d3Interpolate.interpolateRgb(d3Color.rgb('seagreen'), d3Color.hcl('steelblue'));

.tween("zoom", function () {
                const i = d3InterpolateZoom(context.view, [context._focus.x, context._focus.y, context._focus.r * 2]);
                return function (t) { context.zoomTo(i(t)); };
            });

.tween("zoom", function () {
                const i = d3InterpolateZoom(context.view, [context._focus.x, context._focus.y, context._focus.r * 2]);
                return function (t) { context.zoomTo(i(t)); };
            });