我有一个数据框stock_pick并尝试设置某些列的最后一行
stock_pick.iloc[-1]["Regime"] = 0
结果是，
/home/prowler/analysis-toolkit/anaconda2/envs/py3.6/lib/python3.6/site-packages/pandas/core/indexing.py:179: SettingWithCopyWarning:
A value is trying to be set on a copy of a slice from a DataFrame
See the caveats in the documentation: http://pandas.pydata.org/pandas-docs/stable/indexing.html#indexing-view-versus-copy
self._setitem_with_indexer(indexer, value)
选择值并将其分配给最后一行中的特定列的正确方法是什么？
我正在尝试使用全息视图、数据着色器和散景将谷歌手机历史位置映射到地图上。大多数情况下与 datashader 网站中给出的示例非常相似。但是当我做地图覆盖时，因为纬度/经度被弄乱了，所以地图覆盖不起作用。
import datashader as ds
import geoviews as gv
import holoviews as hv
from holoviews.operation.datashader import datashade, dynspread
from datashader import transfer_functions as tf
from colorcet import fire
hv.extension('bokeh')
> df2.head()
lat long
0 -37.7997515 144.9636466
1 -37.7997515 144.9636466
2 -37.7997369 144.9636036
3 -37.7997387 144.9636358
4 -37.7997515 144.9636466
这可以生成数据的图像，
ds_viz = ds.Canvas().points(df2,'lat','long')
tf.set_background(tf.shade(ds_viz, cmap=fire),"black")
但是，当我尝试用地图覆盖它时，它不起作用，
从 bokeh.models 导入 WMTSTileSource
url = 'https://server.arcgisonline.com/ArcGIS/rest/services/World_Imagery/MapServer/tile/{Z}/{Y}/{X}.jpg'
tile_opts = dict(width=1000,height=600,bgcolor='black',show_grid=False)
map_tiles = gv.WMTS(url).opts(style=dict(alpha=0.5), plot=tile_opts)
points = hv.Points(df2, kdims=['long','lat'])
trips = datashade(points, cmap=fire,width=1000, height=600) …