13

我正在尝试在 folium 中绘制雷达数据,而且我快到了。我按照这个示例(边界内的轮廓图数据(纬度,经度,值)并导出 GeoJSON)将我的数据转换为 GeoJson 格式。

nb_class = 20 
collec_poly = plt.contourf(lons,lats,np.array(poshdata), nb_class,alpha=0.5)

gdf = collec_to_gdf(collec_poly) # From link above
gdf.to_json()
colors = [p.get_facecolor().tolist()[0] for p in collec_poly.collections]
gdf['RGBA'] = colors

gdf

这会输出两列:几何和 RGBA。

    RGBA    geometry
0   [0.0, 0.0, 0.713903743316, 1.0] (POLYGON ((-71.57032079644679 42.2775236331535...
1   [0.0, 0.0960784313725, 1.0, 1.0]    (POLYGON ((-71.56719970703125 42.2721176147460...
2   [0.0, 0.503921568627, 1.0, 1.0] (POLYGON ((-71.55678558349609 42.2721176147460...
3   [0.0, 0.896078431373, 0.970904490829, 1.0]  (POLYGON ((-71.52552795410156 42.2849182620049...
4   [0.325743200506, 1.0, 0.641998734978, 1.0]  (POLYGON ((-71.49427795410156 42.2939676156927...
5   [0.641998734978, 1.0, 0.325743200506, 1.0]  (POLYGON ((-71.47344207763672 42.3003084448852...
6   [0.970904490829, 0.959331880901, 0.0, 1.0]  (POLYGON ((-71.26508331298828 42.3200411822557...
7   [1.0, 0.581699346405, 0.0, 1.0] (POLYGON ((-71.15048217773438 42.3333218460720...

从那里我制作我的folium地图:

import folium    

# Picked location between Sudbury and Somerville:
maploc = folium.Map(location=[42.377157,-71.236088],zoom_start=11,tiles="Stamen Toner")

folium.GeoJson(gdf).add_to(maploc)

这创建了我漂亮的叶图,但多边形根本没有着色。如何让轮廓填充正确的颜色?并修复不透明度?

在此处输入图像描述

4

3 回答 3

12

我想我明白了。在我之前的代码中,polygon.get_facecolor() 返回范围为 0-1 的 RGBA 值列表。我添加了这个功能(从这篇文章修改):

def convert_to_hex(rgba_color) :
    red = str(hex(int(rgba_color[0]*255)))[2:].capitalize()
    green = str(hex(int(rgba_color[1]*255)))[2:].capitalize()
    blue = str(hex(int(rgba_color[2]*255)))[2:].capitalize()

    if blue=='0':
        blue = '00'
    if red=='0':
        red = '00'
    if green=='0':
        green='00'

    return '#'+ red + green + blue

将其转换为十六进制字符串。然后:

gdf['RGBA'] = convert_to_hex(colors)

然后在folium中绘制颜色,我这样做:

maploc = folium.Map(location=[42.377157,-71.236088],zoom_start=10,tiles="Stamen Toner")

colors = []
folium.GeoJson(
    gdf,
    style_function=lambda feature: {
        'fillColor': feature['properties']['RGBA'],
        'color' : feature['properties']['RGBA'],
        'weight' : 1,
        'fillOpacity' : 0.5,
        }
    ).add_to(maploc)

这创造了一个非常漂亮的情节!(属性名称有点误导 - 它实际上不是 RGBA 值,而是十六进制字符串。)

于 2016-02-22T16:43:11.127 回答
6

不是专家......我刚开始使用 folium 和 jupyter 并且遇到了类似的问题,但有线条。你说你有 GeoJson 和多边形,颜色包含在我假设的 json 中。

style_function 可能会帮助你得到你想要的东西?

下面的示例是使用此页面生成的:http : //geojson.io/ 我所要做的就是与 style_function 进行“映射”。也可以使用自定义函数,参见: https ://github.com/python-visualization/folium/blob/master/examples/Colormaps.ipynb

import folium
geoJsonData = {
    "features": [
        {
            "geometry": {
                "coordinates": [
                    [
                        12.98583984375,
                        56.70450561416937
                    ],
                    [
                        14.589843749999998,
                        57.604221411628735
                    ],
                    [
                        13.590087890625,
                        58.15331598640629
                    ],
                    [
                        11.953125,
                        57.955674494979526
                    ],
                    [
                        11.810302734375,
                        58.76250326278713
                    ]
                ],
                "type": "LineString"
            },
            "properties": {
                "stroke": "#fc1717",
                "stroke-opacity": 1,
                "stroke-width": 2
            },
            "type": "Feature"
        },
        {
            "geometry": {
                "coordinates": [
                    [
                        14.9468994140625,
                        57.7569377956732
                    ],
                    [
                        15.078735351562498,
                        58.06916140721414
                    ],
                    [
                        15.4302978515625,
                        58.09820267068277
                    ],
                    [
                        15.281982421875002,
                        58.318144965188246
                    ],
                    [
                        15.4852294921875,
                        58.36427519285588
                    ]
                ],
                "type": "LineString"
            },
            "properties": {
                "stroke": "#1f1a95",
                "stroke-opacity": 1,
                "stroke-width": 2
            },
            "type": "Feature"
        }
    ],
    "type": "FeatureCollection"
}
m = folium.Map(location=[ 56.7, 12.9], zoom_start=6)
folium.GeoJson(geoJsonData,
    style_function=lambda x: {
        'color' : x['properties']['stroke'],
        'weight' : x['properties']['stroke-width'],
        'opacity': 0.6,
        'fillColor' : x['properties']['fill'],
        }).add_to(m)
m

git hub 上的 folium 源代码也包括几个不错的示例:
https
://github.com/python-visualization/folium/tree/master/examples 在这里您可以找到可以使用的选项:http:
//leafletjs.com/ reference.html#path-options

希望这能让你前进!

于 2016-02-20T19:52:30.790 回答
1

我还没有足够的声誉点来发表评论,所以这是一个单独的答案,以澄清由edub编写的已接受答案。

Matplotlib 已经有了 colors.to_hex() 方法:

import matplotlib.colors as cl

colors = [cl.to_hex(c) for c in colors]

这将替换已接受答案中的 convert_to_hex() 方法。

于 2020-07-09T23:57:56.873 回答