你好，
我试图通过屏蔽值的上下 10 个百分位数来消除计算出的 NDVI 数据集中的异常值，但我在第 398 行中不断收到错误消息，显示第 398 行： ndvi.gt不是函数。 我怎样才能解决这个问题？
原始代码：
var table = ee.FeatureCollection("users/selenachav5/mangrove_vector"),
Upper =
/* color: #d63000 */
/* shown: false */
/* displayProperties: [
{
"type": "rectangle"
},
{
"type": "marker"
},
{
"type": "rectangle"
}
] */
ee.Geometry({
"type": "GeometryCollection",
"geometries": [
{
"type": "Polygon",
"coordinates": [
[
[
-81.2407135715856,
25.79366283798797
],
[
-81.2407135715856,
25.77758769332227
],
[
-81.22148749736685,
25.77758769332227
],
[
-81.22148749736685,
25.79366283798797
]
]
],
"geodesic": false,
"evenOdd": true
},
{
"type": "Point",
"coordinates": [
-81.32741223482145,
25.738523746255495
]
},
{
"type": "Polygon",
"coordinates": [
[
[
-81.82460825109085,
25.96361611727523
],
[
-81.82460825109085,
24.946857002999202
],
[
-80.1574329581221,
24.946857002999202
],
[
-80.1574329581221,
25.96361611727523
]
]
],
"geodesic": false,
"evenOdd": true
}
],
"coordinates": []
}),
Lower = /* color: #98ff00 */ee.Geometry.Point([-81.16010932282697, 25.231743823283935]),
Mid = /* color: #0b4a8b */ee.Geometry.Point([-81.08192793682238, 25.35792290478201]),
TTI = /* color: #00ffff */ee.Geometry.Point([-81.56369714187413, 25.872789041185186]),
geometry =
/* color: #0000ff */
/* shown: false */
ee.Geometry.Point([-80.93190442232145, 25.542910956897835]),
imageVisParam = {"opacity":1,"bands":["constant"],"max":1,"palette":["ff0000","a52a2a","008000"]},
geometry2 =
/* color: #d63000 */
/* shown: false */
/* displayProperties: [
{
"type": "rectangle"
},
{
"type": "rectangle"
}
] */
ee.Geometry.MultiPolygon(
[[[[-81.81911508702835, 25.95620775711364],
[-81.81911508702835, 24.956817897095913],
[-80.15468637609085, 24.956817897095913],
[-80.15468637609085, 25.95620775711364]]],
[[[-80.9045032706221, 26.01052489646315],
[-80.9045032706221, 25.93644985046701],
[-80.8715442862471, 25.93644985046701],
[-80.8715442862471, 26.01052489646315]]]], null, false),
table2 = ee.FeatureCollection("users/selenachav5/nps_boundary"),
image2 = ee.ImageCollection("LANDSAT/LC08/C02/T1_TOA"),
image3 = ee.ImageCollection("LANDSAT/LC08/C02/T1_RT_TOA"),
image4 = ee.ImageCollection("LANDSAT/LC08/C02/T1_L2");
print(table.limit(10), 'table')
Map.addLayer(table, {}, 'raw table',0)
// Get bounding box for your geometry
var bbox = table.geometry().bounds();
Map.addLayer(bbox, {}, 'bounding box')
// Convert mangrove to image
var mangroveImg = ee.Image(0).paint(table, 1);
Map.addLayer(mangroveImg, {min:0, max:1}, 'mangroveImg')
var enpbound = ee.Image(0).paint(table2, 1);
Map.addLayer(mangroveImg, {min:0, max:1}, 'enpbound')
// Now you can map over the collection and mask out all non-mangrove pixels
function maskNonMangrove(i){
return i.updateMask(mangroveImg).copyProperties(i);
}
function maskENP(i){
return i.updateMask(enpbound).copyProperties(i);
}
function maskL8(im) {
var qa = im.select('QA_PIXEL');
var mask = qa.eq(21824);
return im.updateMask(mask).copyProperties(im);
}
//var water = function(image) {
//var qa = image.select('QA_PIXEL');
/// Check that the cloud bit is off.
// See https://www.usgs.gov/media/files/landsat-8-9-olitirs-collection-2-level-1-data-format-control-book
// var mask = qa.bitwiseAnd(7).eq(0);
// return image.updateMask(mask);
//};
//var image = ee.ImageCollection("LANDSAT/LC08/C01/T1_SR");
var Before = image4
.filterBounds(geometry2)
.filterDate('2013-04-01', '2017-09-08')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var After = image4
.filterBounds(geometry2)
.filterDate('2017-09-09', '2023-01-01')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var Thirteen = image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2013-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
//.map(water)
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var ThirteenM = image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2013-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var FourteenPercent = image4
.filterBounds(geometry2)
.filterDate('2014-01-01', '2014-12-31')
.map(function(im) {return (im.normalizedDifference(['SR_B5', 'SR_B4']))})
.reduce(ee.Reducer.percentile([10]))
var Fourteen = image4
.filterBounds(geometry2)
.filterDate('2014-01-01', '2014-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
.map( function(im) {return im.select('nd').updateMask(im.select('nd').gt(FourteenPercent))})
var FourteenM = image4
.filterBounds(geometry2)
.filterDate('2014-01-01', '2014-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Fifteen = image4
.filterBounds(geometry2)
.filterDate('2015-01-01', '2015-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var FifteenM = image4
.filterBounds(geometry2)
.filterDate('2015-01-01', '2015-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Sixteen = image4
.filterBounds(geometry2)
.filterDate('2016-01-01', '2016-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var SixteenM = image4
.filterBounds(geometry2)
.filterDate('2016-01-01', '2016-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Seventeen = image4
.filterBounds(geometry2)
.filterDate('2017-01-01', '2017-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var SeventeenM = image4
.filterBounds(geometry2)
.filterDate('2017-01-01', '2017-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Eighteen = image4
.filterBounds(geometry2)
.filterDate('2018-01-01', '2018-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var EighteenM = image4
.filterBounds(geometry2)
.filterDate('2018-01-01', '2018-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Nineteen = image4
.filterBounds(geometry2)
.filterDate('2019-01-01', '2019-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var NineteenM = image4
.filterBounds(geometry2)
.filterDate('2019-01-01', '2019-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var Twenty = image4
.filterBounds(geometry2)
.filterDate('2020-01-01', '2020-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var TwentyM = image4
.filterBounds(geometry2)
.filterDate('2020-01-01', '2020-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var TwentyOne= image4
.filterBounds(geometry2)
.filterDate('2021-01-01', '2021-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var TwentyTwo = image4
.filterBounds(geometry2)
.filterDate('2022-01-01', '2022-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var TwentyOneM= image4
.filterBounds(geometry2)
.filterDate('2021-01-01', '2021-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var TwentyTwoM = image4
.filterBounds(geometry2)
.filterDate('2022-01-01', '2022-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
//.map(water)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var DecadePercent = image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2023-12-31')
.map(function(im) {return (im.normalizedDifference(['SR_B5', 'SR_B4']))})
.reduce(ee.Reducer.percentile([10]))
var Decade= image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2022-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
.map(function(im) {var opticalBands = im.select('SR_B.').multiply(0.0000275).add(-0.2);return im.addBands(opticalBands,null,true)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
var DecadeM= image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2022-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
.map(function(im) {return im.select(['SR_B.']).multiply(0.0000275).add(-0.2)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B6']))})
var DecadeO= image4
.filterBounds(geometry2)
.filterDate('2013-01-01', '2022-12-31')
.map(maskL8) // this is fine
.map(maskNonMangrove)
.map(maskENP)
.map(function(im) {var opticalBands = im.select('SR_B.').multiply(0.0000275).add(-0.2);return im.addBands(opticalBands,null,true)})
.map(function(im) {return im.addBands(im.normalizedDifference(['SR_B5', 'SR_B4']))})
.map( function(im) {return im.select('nd').updateMask(im.select('nd').gt(FourteenPercent))})
//.map( function(im) {return im.select('nd').updateMask(im.select('nd').gt(FourteenPercent))})
// Add mean NDVI to the map to inspect
//Map.addLayer(Before.select('nd').mean(), {min:0, max:1, palette:['red','brown','green']}, 'mean NDVI mangroves Before')
//Map.addLayer(After.select('nd').mean(), {min:0, max:1, palette:['red','brown','green']}, 'mean NDVI mangroves After')
Map.addLayer(Thirteen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2013')
Map.addLayer(Fourteen.select('nd'), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2014')
Map.addLayer(Fifteen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2015')
Map.addLayer(Sixteen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2016')
Map.addLayer(Seventeen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2017')
Map.addLayer(Eighteen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2018')
Map.addLayer(Nineteen.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2019')
Map.addLayer(Twenty.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2020')
Map.addLayer(TwentyOne.select('nd').mean(), {min:0, max:0.8, palette:['#ffffcc','#c2e699','#78c679','#31a354','#006837']}, 'NDVI 2021')
Map.addLayer(ThirteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2013')
Map.addLayer(FourteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2014')
Map.addLayer(FifteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2015')
Map.addLayer(SixteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2016')
Map.addLayer(SeventeenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2017')
Map.addLayer(EighteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2018')
Map.addLayer(NineteenM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2019')
Map.addLayer(TwentyM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Mositure 2020')
Map.addLayer(TwentyOneM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2021')
Map.addLayer(TwentyTwoM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Moisture 2022')
Map.addLayer(DecadeM.select('nd').mean(), {min:0, max:0.8, palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']}, 'Decade Mositure')
var vis = {min: 0, max: 0.8, palette:'#ffffcc,#c2e699,#78c679,#31a354,#006837'}
var palette= ['#ffffcc','#c2e699','#78c679','#31a354','#006837']
var vis2 = {min: 0, max: 0.8, palette:'#eff3f,#bdd7e7,#6baed6,#3182bd,#08519c'}
var palette2= ['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c']
function makeColorBarParams(palette2) {
return {
bbox: [0, 0, 1, 0.1],
dimensions: '100x10',
format: 'png',
min: 0,
max: 1,
palette:['#eff3ff','#bdd7e7','#6baed6','#3182bd','#08519c'],
};
}
var colorBar = ui.Thumbnail({
image: ee.Image.pixelLonLat().select(0),
params: makeColorBarParams(vis2.palette2),
style: {stretch: 'horizontal', margin: '0px 8px', maxHeight: '24px'},
});
// Create a panel with three numbers for the legend.
var legendLabels = ui.Panel({
widgets: [
ui.Label(vis2.min, {margin: '4px 8px'}),
ui.Label(
((vis2.max-vis2.min) / 2+vis2.min),
{margin: '4px 8px', textAlign: 'center', stretch: 'horizontal'}),
ui.Label(vis2.max, {margin: '4px 8px'})
],
layout: ui.Panel.Layout.flow('horizontal')
});
var legendTitle = ui.Label({
value: 'Normalized Difference Mositure Index',
style: {fontWeight: 'bold'}
});
// Add the legendPanel to the map.
var legendPanel = ui.Panel([legendTitle, colorBar, legendLabels]);
Map.add(legendPanel);
var ndviB = Before.select('nd')
var ndvia = After.select('nd')
var ndvi = Decade.select('nd')
var ndviOL= DecadeO.select('nd')
var P_95_NDVI = ndvi.reduce(ee.Reducer.percentile([95]));
var P_05_NDVI = ndvi.reduce(ee.Reducer.percentile([5]));
var NDVI_P = ndvi.updateMask(ndvi.gt(P_05_NDVI).and(ndvi.lt(P_95_NDVI)));
var Moisture = DecadeM.select('nd')
var Change = Thirteen.select('nd');Fourteen.select('nd');Fifteen.select('nd');Sixteen.select('nd');Seventeen.select('nd');Eighteen.select('nd');Nineteen.select('nd');Twenty.select('nd');TwentyOne.select('nd')
//print(ui.Chart.image.series(ndviB,Upper,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviA,Upper,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviB,Lower,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviA,Lower,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviB,Mid,ee.Reducer.mean(), 30, 'system:time_start'))
print(ui.Chart.image.series(ndviA,Mid,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviB,TTI,ee.Reducer.mean(), 30, 'system:time_start'))
//print(ui.Chart.image.series(ndviA,TTI,ee.Reducer.mean(), 30, 'system:time_start'))
print(ui.Chart.image.series(ndvi, Mid, ee.Reducer.mean(), 30, 'system:time_start'))
print(ui.Chart.image.series(ndviOL, Mid, ee.Reducer.mean(), 30, 'system:time_start'))
print(ui.Chart.image.series(DecadeM, Mid,ee.Reducer.mean(), 30, 'system:time_start'))
// You need to submit it as an export task问题1：Line 398: ndvi.gt is not a function
这个问题主要的是影像集合和影像之间的差异，function不能直接作用在影像上，所以我们对之前的代码进行分析就可以了，正确代码如下：
var ndviB = Before.select('nd')
var ndvia = After.select('nd')
var ndvi = Decade.select('nd').mosaic()
var ndviOL= DecadeO.select('nd').mosaic()
var P_95_NDVI = ndvi.reduce(ee.Reducer.percentile([95]));
var P_05_NDVI = ndvi.reduce(ee.Reducer.percentile([5]));
var NDVI_P = ndvi.updateMask(ndvi.gt(P_05_NDVI).and(ndvi.lt(P_95_NDVI)));
var Moisture = DecadeM.select('nd')
var Change = Thirteen.select('nd');Fourteen.select('nd');Fifteen.select('nd');Sixteen.select('nd');Seventeen.select('nd');Eighteen.select('nd');Nineteen.select('nd');Twenty.select('nd');TwentyOne.select('nd')问题2：
Error generating chart: No features contain non-null values of "system:time_start".
这个问题请查看：
参看：
(1039条消息) Google Earth Engine（GEE）——求随机点中的长时序的各波段的折线图（附给矢量集合添加时间属性
