function?land?=?landmask（latlonvarargin）
%?landmask?returns?a?logical?array?describing?the?landness?of
%?any?given?lat/lon?arrays.??Requires?Matlab‘s?Mapping?Toolbox.?
%?
%?This?function?uses?Matlab‘s?built-in?coast.mat?file?with?inpolygons
%?to?determing?whether?input?lat/lons?are?inside?or?outside?perimeters?of
%?land?areas.?
%?
%%?Syntax
%?
%??land?=?landmask（latlon）
%??land?=?landmask（...‘landmass‘）
%??land?=?landmask（...quality）
%?
%%?Description?
%?
%?land?=?landmask（latlon）?returns?logical?land?array?corresponding?to
%?the?dimensions?of?input?lat?and?lon.??1?is?land?0?is?not?land.?
%
%?land?=?landmask（...‘landmass‘）?specifies?any?of?the?following?regions?of
%?mask:?
%?
%?*?‘Antarctica‘
%?*?‘Africa?and?Eurasia‘
%?*?‘North?and?South?America‘
%?*?‘Greenland‘
%?*?‘Australia‘
%?*?‘Baffin?Island‘
%?*?‘Ellesmere?Island‘
%?*?‘New?Guinea‘
%?*?‘Great?Britain‘
%?*?‘Borneo‘
%?*?‘Honshu‘
%?*?‘Victoria?Island‘
%?*?‘Celebes‘
%?*?‘New?Zealand?North?Island‘
%?*?‘Sumatra‘
%?*?‘Madagascar‘
%?*?‘Iceland‘
%?*?‘New?Zealand?South?Island‘
%?*?‘Newfoundland‘
%?*?‘Luzon‘
%?*?‘Devon?Island‘
%?*?‘Ireland‘
%?*?‘Cuba‘
%?*?‘Java‘
%?*?‘Mindanao‘
%?
%?land?=?landmask（...quality）?specifies?quality?from?0?to?100.??This
%?option?is?provided?because?for?large?data?sets?the?land?mask?function
%?can?take?quite?some?time.??For?example?on?my?laptop?a?calculating?180x360?land?mask
%?for?all?continents?takes?about?65?seconds?at?100%?quality.?Default
%?quality?is?95?which?takes?about?6?seconds?for?the?same?dataset?on?my?laptop.?
%?The?quality?setting?is?only?used?when?calculating?the?land?mask?using?all
%?of?the?world‘s?continents.?For?single?land?masses?100%?quality?is?assumed.?
%?
%
%%?Example?1:?Is?Topeka?KS?on?land??
%?%?Topeka?Kansas?is?located?at?（39.06N?95.69W）.??Is?Topeka?situatated?on
%?%?land??
%?
%?TopekaLand?=?landmask（39.0695.69）
%?
%%
%?%?As?it?turns?out?yes?Topeka?is?well?grounded.?But?is?it?in?Australia??
%?
%?TopekaAustralia?=?landmask（39.0695.69‘australia‘）
%?
%%?
%?%?Zero?means?nope.?
%?
%%?Example?2:?Gridded?data
%?%?Start?with?some?sample?gridded?data:?
%?
%?[lonlat]?=?meshgrid（linspace（-179?179?180）...
%?????linspace（-89.589.5?180））;
%?z?=?peaks（180）;
%?
%?worldmap（‘world‘）
%?h=pcolorm（latlonz）;?
%?
%%?
%?%?To?mask-out?the?land?area?of?North?and?South?America?set?all?z?values?
%?%?corresponding?to?the?land?area?of?these?two?continents?to?NaN.?Start?by?
%?%?deleting?the?pcolorm?surface?we?plotted?above.?This?calculation?may
%?%?take?about?3?to?5?seconds?on?a?modern?laptop?computer:?
%?
%?delete（h）
%?Americas?=?landmask（latlon‘North?and?South?America‘）;?
%?z（Americas）?=?NaN;?
%?h=pcolorm（latlonz）;?
%?
%%?
%?%?To?instead?mask?out?all?the?world‘s?oceans?set?non-land?areas?to?NaN.?First
%?%?we‘ll?delete?the?last?pcolorm?surface?and?refresh?our?z?data.?Then
%?%?we‘ll?calculate?the?ocean?mask?by?taking?the?logical?not?of?the?land
%?%?mask.
%?%?
%?%?Using?default?quality?of?95?land?mask?calculation?for?our?180x180?grid
%?%?takes?abo

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----
?????文件???????13429??2014-12-05?13:42??landmask\html\landmask_documentation.html
?????文件????????3867??2014-12-05?13:42??landmask\html\landmask_documentation.png
?????文件???????16321??2014-12-05?13:42??landmask\html\landmask_documentation_01.png
?????文件???????16708??2014-12-05?13:42??landmask\html\landmask_documentation_02.png
?????文件???????13777??2014-12-05?13:42??landmask\html\landmask_documentation_03.png
?????文件????????6909??2014-12-05?13:42??landmask\landmask.m
?????文件??????????82??2014-12-05?13:42??__MACOSX\landmask\._landmask.m
?????文件????????3976??2014-12-05?13:42??landmask\landmask_documentation.m
?????文件??????????82??2014-12-05?13:42??__MACOSX\landmask\._landmask_documentation.m
?????文件??????226757??2014-12-05?13:42??landmask\landmass.png
?????文件????????1311??2014-12-05?13:42??license.txt