測地面積
デフォルトの楕円モデルを使って,地球上の測地多角形の面積を計算する.
地球上の測地三角形の面積.
In[1]:=
![Click for copyable input](assets.ja/geodetic-areas/In_20.png)
polygon = Polygon[GeoPosition[{{0, 0}, {0, 90}, {90, 0}}]]
Out[1]=
![](assets.ja/geodetic-areas/O_12.png)
In[2]:=
![Click for copyable input](assets.ja/geodetic-areas/In_21.png)
GeoArea[polygon]
Out[2]=
![](assets.ja/geodetic-areas/O_13.png)
In[3]:=
![Click for copyable input](assets.ja/geodetic-areas/In_22.png)
GeoArea[polygon];
% == GeoArea["World"]/8
Out[3]=
![](assets.ja/geodetic-areas/O_14.png)
大陸の面積.
In[4]:=
![Click for copyable input](assets.ja/geodetic-areas/In_23.png)
polygon = EntityValue[Entity["GeographicRegion", "Africa"], "Polygon"]
Out[4]=
![](assets.ja/geodetic-areas/O_15.png)
In[5]:=
![Click for copyable input](assets.ja/geodetic-areas/In_24.png)
GeoArea[polygon]
Out[5]=
![](assets.ja/geodetic-areas/O_16.png)
世界中の陸地の面積.
In[6]:=
![Click for copyable input](assets.ja/geodetic-areas/In_25.png)
polygon = EntityValue[Entity["GeographicRegion", "World"], "Polygon"];
In[7]:=
![Click for copyable input](assets.ja/geodetic-areas/In_26.png)
GeoArea[polygon]
Out[7]=
![](assets.ja/geodetic-areas/O_17.png)
陸地は,地球の表面積の29%に満たない.
In[8]:=
![Click for copyable input](assets.ja/geodetic-areas/In_27.png)
GeoArea[polygon];
%/GeoArea["World"]
Out[8]=
![](assets.ja/geodetic-areas/O_18.png)