RemovePoint - Maple Help

DataSets[Builtin][WorldMap]

 RemovePoint
 remove one or more point(s) from a WorldMap object

 Calling Sequence RemovePoint(m,ref) RemovePoint(m,p) RemovePoint(m,label)

Parameters

 m - a WorldMap object ref - a Reference to the GeoNames dataset p - a list representing one or more point(s) in m label - a string label for one or more point(s) in m

Description

 • The RemovePoint command removes all points specified by either ref,p, or label from m.
 • If ref is given, all points contained in ref are removed from m.
 • If p is given, p must be a list of either two or three elements. The first element in p is the longitude (x-coordinate in the Geographic projection), and the second element in p is the latitude (y-coordinate in the Geographic projection). The optional third element is a string label for the point.
 • If label is given, all points in m with a string label equal to label are removed.
 • If you try to remove a point that does not exist in m, no change is made to m. For example, if a ref containing three rows is supplied, but only two corresponding points from ref actually exist in m, then the behavior would be the same as if ref contains only those two points.

Examples

 > $\mathrm{ref}≔\mathrm{DataSets}:-\mathrm{Builtin}:-\mathrm{Reference}\left("Geonames"\right)\left[\left[\mathrm{Country}="Canada",\mathrm{Name}="Waterloo"\right]\right]$
 ${\mathrm{ref}}{≔}\left[\begin{array}{ccccc}{\mathrm{Geonames \left(GeoNamesid\right)}}& {\mathrm{Name}}& {\mathrm{Type}}& {\dots }& {\mathrm{\left(7 more\right)}}\\ {\mathrm{6176821}}& {\mathrm{Waterloo}}& {"populated place"}& {\dots }& {}\\ {\mathrm{6176823}}& {\mathrm{Waterloo}}& {"populated place"}& {\dots }& {}\\ {\mathrm{8673866}}& {\mathrm{Waterloo}}& {"third-order administrative division"}& {\dots }& {}\end{array}\right]$ (1)
 > $m≔\mathrm{DataSets}:-\mathrm{Builtin}:-\mathrm{WorldMap}\left(\mathrm{ref}\right)$
 ${m}{≔}\left(\begin{array}{cc}\left[{\mathrm{PLOT}}{}\left({\mathrm{...}}\right)\right]& \begin{array}{c}{\mathrm{A map of the world with 3 points}}\\ {\mathrm{projection: MillerCylindrical}}\end{array}\end{array}\right)$ (2)
 > $\mathrm{GetPointsList}\left(m\right)$
 $\left[\left[{-80.5163900000000012}{,}{43.4667999999999992}{,}{"Waterloo"}\right]{,}\left[{-72.5279599999999931}{,}{45.3367300000000029}{,}{"Waterloo"}\right]{,}\left[{-72.5158200000000051}{,}{45.3500799999999984}{,}{"Waterloo"}\right]\right]$ (3)
 > $\mathrm{RemovePoint}\left(m,\mathrm{ref}\left[1\right]\right)$
 $\left(\begin{array}{cc}\left[{\mathrm{PLOT}}{}\left({\mathrm{...}}\right)\right]& \begin{array}{c}{\mathrm{A map of the world with 2 points}}\\ {\mathrm{projection: MillerCylindrical}}\end{array}\end{array}\right)$ (4)
 > $\mathrm{GetPointsList}\left(m\right)$
 $\left[\left[{-80.5163900000000012}{,}{43.4667999999999992}{,}{"Waterloo"}\right]{,}\left[{-72.5279599999999931}{,}{45.3367300000000029}{,}{"Waterloo"}\right]\right]$ (5)
 > $\mathrm{AddPoints}\left(m,\left[\left[-10,-10,"a"\right],\left[10,-10,"b"\right],\left[10,10,"c"\right],\left[-10,10,"d"\right]\right]\right)$
 $\left(\begin{array}{cc}\left[{\mathrm{PLOT}}{}\left({\mathrm{...}}\right)\right]& \begin{array}{c}{\mathrm{A map of the world with 6 points}}\\ {\mathrm{projection: MillerCylindrical}}\end{array}\end{array}\right)$ (6)
 > $\mathrm{GetPointsList}\left(m\right)$
 $\left[\left[{-80.5163900000000012}{,}{43.4667999999999992}{,}{"Waterloo"}\right]{,}\left[{-72.5279599999999931}{,}{45.3367300000000029}{,}{"Waterloo"}\right]{,}\left[{-10}{,}{-10}{,}{"a"}\right]{,}\left[{-10}{,}{10}{,}{"d"}\right]{,}\left[{10}{,}{-10}{,}{"b"}\right]{,}\left[{10}{,}{10}{,}{"c"}\right]\right]$ (7)
 > $\mathrm{RemovePoint}\left(m,\left[-10,-10\right]\right)$
 $\left(\begin{array}{cc}\left[{\mathrm{PLOT}}{}\left({\mathrm{...}}\right)\right]& \begin{array}{c}{\mathrm{A map of the world with 5 points}}\\ {\mathrm{projection: MillerCylindrical}}\end{array}\end{array}\right)$ (8)
 > $\mathrm{GetPointsList}\left(m\right)$
 $\left[\left[{-80.5163900000000012}{,}{43.4667999999999992}{,}{"Waterloo"}\right]{,}\left[{-72.5279599999999931}{,}{45.3367300000000029}{,}{"Waterloo"}\right]{,}\left[{-10}{,}{10}{,}{"d"}\right]{,}\left[{10}{,}{-10}{,}{"b"}\right]{,}\left[{10}{,}{10}{,}{"c"}\right]\right]$ (9)
 > $\mathrm{Display}\left(m\right)$
 > 

Compatibility

 • The DataSets[Builtin][WorldMap][RemovePoint] command was introduced in Maple 2017.