当我尝试动态更改使用Google Maps JavaScript API制作的热图中的半径时，我会遇到一些奇怪的行为。我试图在HTML中添加一个滑块，以便用户可以选择半径。我为不透明度做了同样的事情，它工作得非常漂亮。但是，当我调整半径滑块时，会发生奇怪的事情。它只能在地图的一个图块中进行调整，当我缩放时，整个热图叠加将永远消失。 （缩放行为也变得非常棘手。）作为这种行为的一个简单示例，我将代码放在下面的Google Maps JavaScript API heatmap example中，代码的唯一变化是实现不透明度和半径的滑块。你能看出我的问题在哪里吗？我唯一的更改是在代码的最底部，我已经评论过它们以帮助您查看。
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Heatmaps</title>
<style>
html, body, #map-canvas {
height: 100%;
margin: 0px;
padding: 0px
}
#panel {
position: absolute;
top: 5px;
left: 50%;
margin-left: -180px;
z-index: 5;
background-color: #fff;
padding: 5px;
border: 1px solid #999;
}
</style>
<script src="https://maps.googleapis.com/maps/api/js?v=3.exp&sensor=false&libraries=visualization"></script>
<script>
// Adding 500 Data Points
var map, pointarray, heatmap;
var taxiData = [
new google.maps.LatLng(37.782551, -122.445368),
new google.maps.LatLng(37.782745, -122.444586),
new google.maps.LatLng(37.782842, -122.443688),
new google.maps.LatLng(37.782919, -122.442815),
new google.maps.LatLng(37.782992, -122.442112),
new google.maps.LatLng(37.783100, -122.441461),
new google.maps.LatLng(37.783206, -122.440829),
new google.maps.LatLng(37.783273, -122.440324),
new google.maps.LatLng(37.783316, -122.440023),
new google.maps.LatLng(37.783357, -122.439794),
new google.maps.LatLng(37.783371, -122.439687),
new google.maps.LatLng(37.783368, -122.439666),
new google.maps.LatLng(37.783383, -122.439594),
new google.maps.LatLng(37.783508, -122.439525),
new google.maps.LatLng(37.783842, -122.439591),
new google.maps.LatLng(37.784147, -122.439668),
new google.maps.LatLng(37.784206, -122.439686),
new google.maps.LatLng(37.784386, -122.439790),
new google.maps.LatLng(37.784701, -122.439902),
new google.maps.LatLng(37.784965, -122.439938),
new google.maps.LatLng(37.785010, -122.439947),
new google.maps.LatLng(37.785360, -122.439952),
new google.maps.LatLng(37.785715, -122.440030),
new google.maps.LatLng(37.786117, -122.440119),
new google.maps.LatLng(37.786564, -122.440209),
new google.maps.LatLng(37.786905, -122.440270),
new google.maps.LatLng(37.786956, -122.440279),
new google.maps.LatLng(37.800224, -122.433520),
new google.maps.LatLng(37.800155, -122.434101),
new google.maps.LatLng(37.800160, -122.434430),
new google.maps.LatLng(37.800378, -122.434527),
new google.maps.LatLng(37.800738, -122.434598),
new google.maps.LatLng(37.800938, -122.434650),
new google.maps.LatLng(37.801024, -122.434889),
new google.maps.LatLng(37.800955, -122.435392),
new google.maps.LatLng(37.800886, -122.435959),
new google.maps.LatLng(37.800811, -122.436275),
new google.maps.LatLng(37.800788, -122.436299),
new google.maps.LatLng(37.800719, -122.436302),
new google.maps.LatLng(37.800702, -122.436298),
new google.maps.LatLng(37.800661, -122.436273),
new google.maps.LatLng(37.800395, -122.436172),
new google.maps.LatLng(37.800228, -122.436116),
new google.maps.LatLng(37.800169, -122.436130),
new google.maps.LatLng(37.800066, -122.436167),
new google.maps.LatLng(37.784345, -122.422922),
new google.maps.LatLng(37.784389, -122.422926),
new google.maps.LatLng(37.784437, -122.422924),
new google.maps.LatLng(37.784746, -122.422818),
new google.maps.LatLng(37.785436, -122.422959),
new google.maps.LatLng(37.786120, -122.423112),
new google.maps.LatLng(37.786433, -122.423029),
new google.maps.LatLng(37.786631, -122.421213),
new google.maps.LatLng(37.786660, -122.421033),
new google.maps.LatLng(37.786801, -122.420141),
new google.maps.LatLng(37.786823, -122.420034),
new google.maps.LatLng(37.786831, -122.419916),
new google.maps.LatLng(37.787034, -122.418208),
new google.maps.LatLng(37.787056, -122.418034),
new google.maps.LatLng(37.787169, -122.417145),
new google.maps.LatLng(37.787217, -122.416715),
new google.maps.LatLng(37.786144, -122.416403),
new google.maps.LatLng(37.785292, -122.416257),
new google.maps.LatLng(37.780666, -122.390374),
new google.maps.LatLng(37.780501, -122.391281),
new google.maps.LatLng(37.780148, -122.392052),
new google.maps.LatLng(37.780173, -122.391148),
new google.maps.LatLng(37.780693, -122.390592),
new google.maps.LatLng(37.781261, -122.391142),
new google.maps.LatLng(37.781808, -122.391730),
new google.maps.LatLng(37.782340, -122.392341),
new google.maps.LatLng(37.782812, -122.393022),
new google.maps.LatLng(37.783300, -122.393672),
new google.maps.LatLng(37.783809, -122.394275),
new google.maps.LatLng(37.784246, -122.394979),
new google.maps.LatLng(37.784791, -122.395958),
new google.maps.LatLng(37.785675, -122.396746),
new google.maps.LatLng(37.786262, -122.395780),
new google.maps.LatLng(37.786776, -122.395093),
new google.maps.LatLng(37.787282, -122.394426),
new google.maps.LatLng(37.787783, -122.393767),
new google.maps.LatLng(37.788343, -122.393184),
new google.maps.LatLng(37.788895, -122.392506),
new google.maps.LatLng(37.789371, -122.391701),
new google.maps.LatLng(37.789722, -122.390952),
new google.maps.LatLng(37.790315, -122.390305),
new google.maps.LatLng(37.790738, -122.389616),
new google.maps.LatLng(37.779448, -122.438702),
new google.maps.LatLng(37.779023, -122.438585),
new google.maps.LatLng(37.778542, -122.438492),
new google.maps.LatLng(37.778100, -122.438411),
new google.maps.LatLng(37.777986, -122.438376),
new google.maps.LatLng(37.777680, -122.438313),
new google.maps.LatLng(37.777316, -122.438273),
new google.maps.LatLng(37.777135, -122.438254),
new google.maps.LatLng(37.776987, -122.438303),
new google.maps.LatLng(37.776946, -122.438404),
new google.maps.LatLng(37.776944, -122.438467),
new google.maps.LatLng(37.776892, -122.438459),
new google.maps.LatLng(37.776842, -122.438442),
new google.maps.LatLng(37.776822, -122.438391),
new google.maps.LatLng(37.776814, -122.438412),
new google.maps.LatLng(37.776787, -122.438628),
new google.maps.LatLng(37.776729, -122.438650),
new google.maps.LatLng(37.776759, -122.438677),
new google.maps.LatLng(37.776772, -122.438498),
new google.maps.LatLng(37.776787, -122.438389),
new google.maps.LatLng(37.776848, -122.438283),
new google.maps.LatLng(37.776870, -122.438239),
new google.maps.LatLng(37.777015, -122.438198),
new google.maps.LatLng(37.777333, -122.438256),
new google.maps.LatLng(37.777595, -122.438308),
new google.maps.LatLng(37.777797, -122.438344),
new google.maps.LatLng(37.778160, -122.438442),
new google.maps.LatLng(37.778414, -122.438508),
new google.maps.LatLng(37.778445, -122.438516),
new google.maps.LatLng(37.778503, -122.438529),
new google.maps.LatLng(37.778607, -122.438549),
new google.maps.LatLng(37.778670, -122.438644),
new google.maps.LatLng(37.778847, -122.438706),
new google.maps.LatLng(37.779240, -122.438744),
new google.maps.LatLng(37.779738, -122.438822),
new google.maps.LatLng(37.780201, -122.438882),
new google.maps.LatLng(37.780400, -122.438905),
new google.maps.LatLng(37.780501, -122.438921),
new google.maps.LatLng(37.780892, -122.438986),
new google.maps.LatLng(37.781446, -122.439087),
new google.maps.LatLng(37.781985, -122.439199),
new google.maps.LatLng(37.782239, -122.439249),
new google.maps.LatLng(37.782286, -122.439266),
new google.maps.LatLng(37.797847, -122.429388),
new google.maps.LatLng(37.797874, -122.429180),
new google.maps.LatLng(37.797885, -122.429069),
new google.maps.LatLng(37.797887, -122.429050),
new google.maps.LatLng(37.797933, -122.428954),
new google.maps.LatLng(37.798242, -122.428990),
new google.maps.LatLng(37.798617, -122.429075),
new google.maps.LatLng(37.798719, -122.429092),
new google.maps.LatLng(37.798944, -122.429145),
new google.maps.LatLng(37.799320, -122.429251),
new google.maps.LatLng(37.799590, -122.429309),
new google.maps.LatLng(37.799677, -122.429324),
new google.maps.LatLng(37.799966, -122.429360),
new google.maps.LatLng(37.800288, -122.429430),
new google.maps.LatLng(37.800443, -122.429461),
new google.maps.LatLng(37.800465, -122.429474),
new google.maps.LatLng(37.800644, -122.429540),
new google.maps.LatLng(37.800948, -122.429620),
new google.maps.LatLng(37.801242, -122.429685),
new google.maps.LatLng(37.801375, -122.429702),
new google.maps.LatLng(37.801400, -122.429703),
new google.maps.LatLng(37.801453, -122.429707),
new google.maps.LatLng(37.801473, -122.429709),
new google.maps.LatLng(37.801532, -122.429707),
new google.maps.LatLng(37.801852, -122.429729),
new google.maps.LatLng(37.802173, -122.429789),
new google.maps.LatLng(37.802459, -122.429847),
new google.maps.LatLng(37.802554, -122.429825),
new google.maps.LatLng(37.802647, -122.429549),
new google.maps.LatLng(37.802693, -122.429179),
new google.maps.LatLng(37.802729, -122.428751),
new google.maps.LatLng(37.766104, -122.409291),
new google.maps.LatLng(37.766103, -122.409268),
new google.maps.LatLng(37.766138, -122.409229),
new google.maps.LatLng(37.766183, -122.409231),
new google.maps.LatLng(37.766153, -122.409276),
new google.maps.LatLng(37.766005, -122.409365),
new google.maps.LatLng(37.765897, -122.409570),
new google.maps.LatLng(37.765767, -122.409739),
new google.maps.LatLng(37.765693, -122.410389),
new google.maps.LatLng(37.765615, -122.411201),
new google.maps.LatLng(37.765533, -122.412121),
new google.maps.LatLng(37.765467, -122.412939),
new google.maps.LatLng(37.765444, -122.414821),
new google.maps.LatLng(37.765444, -122.414964),
new google.maps.LatLng(37.765318, -122.415424),
new google.maps.LatLng(37.763961, -122.415296),
new google.maps.LatLng(37.763115, -122.415196),
new google.maps.LatLng(37.762967, -122.415183),
new google.maps.LatLng(37.762278, -122.415127),
new google.maps.LatLng(37.761675, -122.415055),
new google.maps.LatLng(37.760932, -122.414988),
new google.maps.LatLng(37.759337, -122.414862),
new google.maps.LatLng(37.773187, -122.421922),
new google.maps.LatLng(37.773043, -122.422118),
new google.maps.LatLng(37.773007, -122.422165),
new google.maps.LatLng(37.772979, -122.422219),
new google.maps.LatLng(37.772865, -122.422394),
new google.maps.LatLng(37.772779, -122.422503),
new google.maps.LatLng(37.772676, -122.422701),
new google.maps.LatLng(37.772606, -122.422806),
new google.maps.LatLng(37.772566, -122.422840),
new google.maps.LatLng(37.772508, -122.422852),
new google.maps.LatLng(37.772387, -122.423011),
new google.maps.LatLng(37.772099, -122.423328),
new google.maps.LatLng(37.771704, -122.423783),
new google.maps.LatLng(37.771481, -122.424081),
new google.maps.LatLng(37.771400, -122.424179),
new google.maps.LatLng(37.771352, -122.424220),
new google.maps.LatLng(37.771248, -122.424327),
new google.maps.LatLng(37.770904, -122.424781),
new google.maps.LatLng(37.770520, -122.425283),
new google.maps.LatLng(37.770337, -122.425553),
new google.maps.LatLng(37.770128, -122.425832),
new google.maps.LatLng(37.769756, -122.426331),
new google.maps.LatLng(37.769300, -122.426902),
new google.maps.LatLng(37.769132, -122.427065),
new google.maps.LatLng(37.769092, -122.427103),
new google.maps.LatLng(37.768979, -122.427172),
new google.maps.LatLng(37.768595, -122.427634),
new google.maps.LatLng(37.768372, -122.427913),
new google.maps.LatLng(37.768337, -122.427961),
new google.maps.LatLng(37.768244, -122.428138),
new google.maps.LatLng(37.767942, -122.428581),
new google.maps.LatLng(37.767482, -122.429094),
new google.maps.LatLng(37.767031, -122.429606),
new google.maps.LatLng(37.766732, -122.429986),
new google.maps.LatLng(37.766680, -122.430058),
new google.maps.LatLng(37.766633, -122.430109),
new google.maps.LatLng(37.766580, -122.430211),
new google.maps.LatLng(37.766367, -122.430594),
new google.maps.LatLng(37.765910, -122.431137),
new google.maps.LatLng(37.765353, -122.431806),
new google.maps.LatLng(37.764962, -122.432298),
new google.maps.LatLng(37.764868, -122.432486),
new google.maps.LatLng(37.764518, -122.432913),
new google.maps.LatLng(37.763435, -122.434173),
new google.maps.LatLng(37.762847, -122.434953),
new google.maps.LatLng(37.762291, -122.435935),
new google.maps.LatLng(37.762224, -122.436074),
new google.maps.LatLng(37.761957, -122.436892),
new google.maps.LatLng(37.761652, -122.438886),
new google.maps.LatLng(37.761284, -122.439955),
new google.maps.LatLng(37.761210, -122.440068),
new google.maps.LatLng(37.761064, -122.440720),
new google.maps.LatLng(37.761040, -122.441411),
new google.maps.LatLng(37.761048, -122.442324),
new google.maps.LatLng(37.760851, -122.443118),
new google.maps.LatLng(37.759977, -122.444591),
new google.maps.LatLng(37.759913, -122.444698),
new google.maps.LatLng(37.759623, -122.445065),
new google.maps.LatLng(37.758902, -122.445158),
new google.maps.LatLng(37.758428, -122.444570),
new google.maps.LatLng(37.757687, -122.443340),
new google.maps.LatLng(37.757583, -122.443240),
new google.maps.LatLng(37.757019, -122.442787),
new google.maps.LatLng(37.756603, -122.442322),
new google.maps.LatLng(37.756380, -122.441602),
new google.maps.LatLng(37.755790, -122.441382),
new google.maps.LatLng(37.754493, -122.442133),
new google.maps.LatLng(37.754361, -122.442206),
new google.maps.LatLng(37.753719, -122.442650),
new google.maps.LatLng(37.753096, -122.442915),
new google.maps.LatLng(37.751617, -122.443211),
new google.maps.LatLng(37.751496, -122.443246),
new google.maps.LatLng(37.750733, -122.443428),
new google.maps.LatLng(37.750126, -122.443536),
new google.maps.LatLng(37.750103, -122.443784),
new google.maps.LatLng(37.750390, -122.444010),
new google.maps.LatLng(37.750448, -122.444013),
new google.maps.LatLng(37.750536, -122.444040),
new google.maps.LatLng(37.750493, -122.444141),
new google.maps.LatLng(37.790859, -122.402808),
new google.maps.LatLng(37.790864, -122.402768),
new google.maps.LatLng(37.790995, -122.402539),
new google.maps.LatLng(37.791148, -122.402172),
new google.maps.LatLng(37.791385, -122.401312),
new google.maps.LatLng(37.791405, -122.400776),
new google.maps.LatLng(37.791288, -122.400528),
new google.maps.LatLng(37.791113, -122.400441),
new google.maps.LatLng(37.791027, -122.400395),
new google.maps.LatLng(37.791094, -122.400311),
new google.maps.LatLng(37.791211, -122.400183),
new google.maps.LatLng(37.791060, -122.399334),
new google.maps.LatLng(37.790538, -122.398718),
new google.maps.LatLng(37.790095, -122.398086),
new google.maps.LatLng(37.789644, -122.397360),
new google.maps.LatLng(37.789254, -122.396844),
new google.maps.LatLng(37.788855, -122.396397),
new google.maps.LatLng(37.788483, -122.395963),
new google.maps.LatLng(37.788015, -122.395365),
new google.maps.LatLng(37.787558, -122.394735),
new google.maps.LatLng(37.787472, -122.394323),
new google.maps.LatLng(37.787630, -122.394025),
new google.maps.LatLng(37.787767, -122.393987),
new google.maps.LatLng(37.787486, -122.394452),
new google.maps.LatLng(37.786977, -122.395043),
new google.maps.LatLng(37.786583, -122.395552),
new google.maps.LatLng(37.786540, -122.395610),
new google.maps.LatLng(37.786516, -122.395659),
new google.maps.LatLng(37.786378, -122.395707),
new google.maps.LatLng(37.786044, -122.395362),
new google.maps.LatLng(37.785598, -122.394715),
new google.maps.LatLng(37.785321, -122.394361),
new google.maps.LatLng(37.785207, -122.394236),
new google.maps.LatLng(37.785751, -122.394062),
new google.maps.LatLng(37.785996, -122.393881),
new google.maps.LatLng(37.786092, -122.393830),
new google.maps.LatLng(37.785998, -122.393899),
new google.maps.LatLng(37.785114, -122.394365),
new google.maps.LatLng(37.785022, -122.394441),
new google.maps.LatLng(37.784823, -122.394635),
new google.maps.LatLng(37.784719, -122.394629),
new google.maps.LatLng(37.785069, -122.394176),
new google.maps.LatLng(37.785500, -122.393650),
new google.maps.LatLng(37.785770, -122.393291),
new google.maps.LatLng(37.785839, -122.393159),
new google.maps.LatLng(37.782651, -122.400628),
new google.maps.LatLng(37.782616, -122.400599),
new google.maps.LatLng(37.782702, -122.400470),
new google.maps.LatLng(37.782915, -122.400192),
new google.maps.LatLng(37.783137, -122.399887),
new google.maps.LatLng(37.783414, -122.399519),
new google.maps.LatLng(37.783629, -122.399237),
new google.maps.LatLng(37.783688, -122.399157),
new google.maps.LatLng(37.783716, -122.399106),
new google.maps.LatLng(37.783798, -122.399072),
new google.maps.LatLng(37.783997, -122.399186),
new google.maps.LatLng(37.784271, -122.399538),
new google.maps.LatLng(37.784577, -122.399948),
new google.maps.LatLng(37.784828, -122.400260),
new google.maps.LatLng(37.784999, -122.400477),
new google.maps.LatLng(37.785113, -122.400651),
new google.maps.LatLng(37.785155, -122.400703),
new google.maps.LatLng(37.785192, -122.400749),
new google.maps.LatLng(37.785278, -122.400839),
new google.maps.LatLng(37.785387, -122.400857),
new google.maps.LatLng(37.785478, -122.400890),
new google.maps.LatLng(37.785526, -122.401022),
new google.maps.LatLng(37.785598, -122.401148),
new google.maps.LatLng(37.785631, -122.401202),
new google.maps.LatLng(37.785660, -122.401267),
new google.maps.LatLng(37.803986, -122.426035),
new google.maps.LatLng(37.804102, -122.425089),
new google.maps.LatLng(37.804211, -122.424156),
new google.maps.LatLng(37.803861, -122.423385),
new google.maps.LatLng(37.803151, -122.423214),
new google.maps.LatLng(37.802439, -122.423077),
new google.maps.LatLng(37.801740, -122.422905),
new google.maps.LatLng(37.801069, -122.422785),
new google.maps.LatLng(37.800345, -122.422649),
new google.maps.LatLng(37.799633, -122.422603),
new google.maps.LatLng(37.799750, -122.421700),
new google.maps.LatLng(37.799885, -122.420854),
new google.maps.LatLng(37.799209, -122.420607),
new google.maps.LatLng(37.795656, -122.400395),
new google.maps.LatLng(37.795203, -122.400304),
new google.maps.LatLng(37.778738, -122.415584),
new google.maps.LatLng(37.778812, -122.415189),
new google.maps.LatLng(37.778824, -122.415092),
new google.maps.LatLng(37.778833, -122.414932),
new google.maps.LatLng(37.778834, -122.414898),
new google.maps.LatLng(37.778740, -122.414757),
new google.maps.LatLng(37.778501, -122.414433),
new google.maps.LatLng(37.778182, -122.414026),
new google.maps.LatLng(37.777851, -122.413623),
new google.maps.LatLng(37.777486, -122.413166),
new google.maps.LatLng(37.777109, -122.412674),
new google.maps.LatLng(37.776743, -122.412186),
new google.maps.LatLng(37.776440, -122.411800),
new google.maps.LatLng(37.776295, -122.411614),
new google.maps.LatLng(37.776158, -122.411440),
new google.maps.LatLng(37.775806, -122.410997),
new google.maps.LatLng(37.775422, -122.410484),
new google.maps.LatLng(37.775126, -122.410087),
new google.maps.LatLng(37.775012, -122.409854),
new google.maps.LatLng(37.775164, -122.409573),
new google.maps.LatLng(37.775498, -122.409180),
new google.maps.LatLng(37.775868, -122.408730),
new google.maps.LatLng(37.776256, -122.408240),
new google.maps.LatLng(37.776519, -122.407928),
new google.maps.LatLng(37.776539, -122.407904),
new google.maps.LatLng(37.776595, -122.407854),
new google.maps.LatLng(37.776853, -122.407547),
new google.maps.LatLng(37.777234, -122.407087),
new google.maps.LatLng(37.777644, -122.406558),
new google.maps.LatLng(37.778066, -122.406017),
new google.maps.LatLng(37.778468, -122.405499),
new google.maps.LatLng(37.778866, -122.404995),
new google.maps.LatLng(37.779295, -122.404455),
new google.maps.LatLng(37.781043, -122.402288),
new google.maps.LatLng(37.781399, -122.401823),
new google.maps.LatLng(37.781727, -122.401407),
new google.maps.LatLng(37.781853, -122.401247),
new google.maps.LatLng(37.781894, -122.401195),
new google.maps.LatLng(37.782076, -122.400977),
new google.maps.LatLng(37.782338, -122.400603),
new google.maps.LatLng(37.782666, -122.400133),
new google.maps.LatLng(37.783048, -122.399634),
new google.maps.LatLng(37.783450, -122.399198),
new google.maps.LatLng(37.783791, -122.398998),
new google.maps.LatLng(37.784177, -122.398959),
new google.maps.LatLng(37.784388, -122.398971),
new google.maps.LatLng(37.784404, -122.399128),
new google.maps.LatLng(37.784586, -122.399524),
new google.maps.LatLng(37.784835, -122.399927),
new google.maps.LatLng(37.785116, -122.400307),
new google.maps.LatLng(37.785282, -122.400539),
new google.maps.LatLng(37.785346, -122.400692),
new google.maps.LatLng(37.765769, -122.407201),
new google.maps.LatLng(37.765790, -122.407414),
new google.maps.LatLng(37.765802, -122.407755),
new google.maps.LatLng(37.765791, -122.408219),
new google.maps.LatLng(37.765763, -122.408759),
new google.maps.LatLng(37.765726, -122.409348),
new google.maps.LatLng(37.765716, -122.409882),
new google.maps.LatLng(37.765708, -122.410202),
new google.maps.LatLng(37.765705, -122.410253),
new google.maps.LatLng(37.765707, -122.410369),
new google.maps.LatLng(37.765692, -122.410720),
new google.maps.LatLng(37.765699, -122.411215),
new google.maps.LatLng(37.765687, -122.411789),
new google.maps.LatLng(37.765666, -122.412373),
new google.maps.LatLng(37.765598, -122.412883),
new google.maps.LatLng(37.765543, -122.413039),
new google.maps.LatLng(37.765532, -122.413125),
new google.maps.LatLng(37.765500, -122.413553),
new google.maps.LatLng(37.765448, -122.414053),
new google.maps.LatLng(37.765388, -122.414645),
new google.maps.LatLng(37.765323, -122.415250),
new google.maps.LatLng(37.765303, -122.415847),
new google.maps.LatLng(37.765251, -122.416439),
new google.maps.LatLng(37.765204, -122.417020),
new google.maps.LatLng(37.765172, -122.417556),
new google.maps.LatLng(37.765164, -122.418075),
new google.maps.LatLng(37.765153, -122.418618),
new google.maps.LatLng(37.765136, -122.419112),
new google.maps.LatLng(37.765129, -122.419378),
new google.maps.LatLng(37.765119, -122.419481),
new google.maps.LatLng(37.765100, -122.419852),
new google.maps.LatLng(37.765083, -122.420349),
new google.maps.LatLng(37.765045, -122.420930),
new google.maps.LatLng(37.764992, -122.421481),
new google.maps.LatLng(37.764980, -122.421695),
new google.maps.LatLng(37.764993, -122.421843),
new google.maps.LatLng(37.764986, -122.422255),
new google.maps.LatLng(37.764975, -122.422823),
new google.maps.LatLng(37.764939, -122.423411),
new google.maps.LatLng(37.764902, -122.424014),
new google.maps.LatLng(37.764853, -122.424576),
new google.maps.LatLng(37.764826, -122.424922),
new google.maps.LatLng(37.764796, -122.425375),
new google.maps.LatLng(37.764782, -122.425869),
new google.maps.LatLng(37.764768, -122.426089),
new google.maps.LatLng(37.764766, -122.426117),
new google.maps.LatLng(37.764723, -122.426276),
new google.maps.LatLng(37.764681, -122.426649),
new google.maps.LatLng(37.782012, -122.404200),
new google.maps.LatLng(37.781574, -122.404911),
new google.maps.LatLng(37.781055, -122.405597),
new google.maps.LatLng(37.780479, -122.406341),
new google.maps.LatLng(37.779996, -122.406939),
new google.maps.LatLng(37.779459, -122.407613),
new google.maps.LatLng(37.778953, -122.408228),
new google.maps.LatLng(37.778409, -122.408839),
new google.maps.LatLng(37.777842, -122.409501),
new google.maps.LatLng(37.777334, -122.410181),
new google.maps.LatLng(37.776809, -122.410836),
new google.maps.LatLng(37.776240, -122.411514),
new google.maps.LatLng(37.775725, -122.412145),
new google.maps.LatLng(37.775190, -122.412805),
new google.maps.LatLng(37.774672, -122.413464),
new google.maps.LatLng(37.774084, -122.414186),
new google.maps.LatLng(37.773533, -122.413636),
new google.maps.LatLng(37.773021, -122.413009),
new google.maps.LatLng(37.772501, -122.412371),
new google.maps.LatLng(37.771964, -122.411681),
new google.maps.LatLng(37.771479, -122.411078),
new google.maps.LatLng(37.770992, -122.410477),
new google.maps.LatLng(37.770467, -122.409801),
new google.maps.LatLng(37.770090, -122.408904),
new google.maps.LatLng(37.769657, -122.408103),
new google.maps.LatLng(37.769132, -122.407276),
new google.maps.LatLng(37.768564, -122.406469),
new google.maps.LatLng(37.767980, -122.405745),
new google.maps.LatLng(37.767380, -122.405299),
new google.maps.LatLng(37.766604, -122.405297),
new google.maps.LatLng(37.765838, -122.405200),
new google.maps.LatLng(37.765139, -122.405139),
new google.maps.LatLng(37.764457, -122.405094),
new google.maps.LatLng(37.763716, -122.405142),
new google.maps.LatLng(37.762932, -122.405398),
new google.maps.LatLng(37.762126, -122.405813),
new google.maps.LatLng(37.761344, -122.406215),
new google.maps.LatLng(37.760556, -122.406495),
new google.maps.LatLng(37.759732, -122.406484),
new google.maps.LatLng(37.758910, -122.406228),
new google.maps.LatLng(37.758182, -122.405695),
new google.maps.LatLng(37.757676, -122.405118),
new google.maps.LatLng(37.757039, -122.404346),
new google.maps.LatLng(37.756335, -122.403719),
new google.maps.LatLng(37.755503, -122.403406),
new google.maps.LatLng(37.754665, -122.403242),
new google.maps.LatLng(37.753837, -122.403172),
new google.maps.LatLng(37.752986, -122.403112),
new google.maps.LatLng(37.751266, -122.403355)
];
function initialize() {
var mapOptions = {
zoom: 13,
center: new google.maps.LatLng(37.774546, -122.433523),
mapTypeId: google.maps.MapTypeId.SATELLITE
};
map = new google.maps.Map(document.getElementById('map-canvas'),
mapOptions);
var pointArray = new google.maps.MVCArray(taxiData);
heatmap = new google.maps.visualization.HeatmapLayer({
data: pointArray
});
heatmap.setMap(map);
}
function toggleHeatmap() {
heatmap.setMap(heatmap.getMap() ? null : map);
}
function changeGradient() {
var gradient = [
'rgba(0, 255, 255, 0)',
'rgba(0, 255, 255, 1)',
'rgba(0, 191, 255, 1)',
'rgba(0, 127, 255, 1)',
'rgba(0, 63, 255, 1)',
'rgba(0, 0, 255, 1)',
'rgba(0, 0, 223, 1)',
'rgba(0, 0, 191, 1)',
'rgba(0, 0, 159, 1)',
'rgba(0, 0, 127, 1)',
'rgba(63, 0, 91, 1)',
'rgba(127, 0, 63, 1)',
'rgba(191, 0, 31, 1)',
'rgba(255, 0, 0, 1)'
]
heatmap.set('gradient', heatmap.get('gradient') ? null : gradient);
}
function changeRadius(r) {
/* This was the original line in the example code.
It simply toggles between default and radius=20
when a button is clicked. */
//heatmap.set('radius', heatmap.get('radius') ? null : 20);
/* I've replaced it with this. */
heatmap.set('radius', r);
}
function changeOpacity(o) {
/* This was the original line in the example code.
It simply toggles between default and opacity=0.2
when a button is clicked. */
//heatmap.set('opacity', heatmap.get('opacity') ? null : 0.2);
/* I've replaced it with this. (works beautifully) */
heatmap.set('opacity', o);
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
</head>
<body>
<div id="panel">
<button onclick="toggleHeatmap()">Toggle Heatmap</button>
<button onclick="changeGradient()">Change gradient</button>
<!-- The next two lines are the original buttons -->
<!--button onclick="changeRadius()">Change radius</button-->
<!--button onclick="changeOpacity()">Change opacity</button-->
<!-- These are the sliders I added. Opacity works fine. Radius does not. -->
Radius
<input type="range" id="radiusSlider" onchange="changeRadius(radiusSlider.value)" min="1" max="40" step="1" value="12">
Opacity
<input type="range" id="opacitySlider" onchange="changeOpacity(opacitySlider.value)" min="0" max="1" step=".01" value=".6">
</div>
<div id="map-canvas"></div>
</body>
</html>
答案 0 :(得分：1)
半径应为数字，但radiusSlider.value为字符串。
使用
heatmap.set('radius', r * 1);