<DIV align=center><FONT size=2>7,864,320</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>30G</FONT></DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>4級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:50,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1,966,080</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>7.5G</FONT></DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>5級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:100,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>491,520</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1.875G</FONT></DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>6級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:250,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>122,880</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT></DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>7級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:500,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>30,720</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>8級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:1,000,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>7,680</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>9級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:2,500,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1,920</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>10級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:5,000,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>480</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>11級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:10,000,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>120</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR>
<TR>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>12級(jí)</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>1:50,000,000</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2>30</FONT></DIV></TD>
<TD vAlign=top width="25%">
<DIV align=center><FONT size=2></FONT>&nbsp;</DIV></TD></TR></TBODY></TABLE>
<P class=MsoNormal style="MARGIN-LEFT: 21pt; TEXT-INDENT: 21pt"><SPAN style="FONT-FAMILY: 宋體">由以上分析可見在大比例尺下若全部生成</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">其數(shù)量是很巨大的</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">考慮到某些大比例尺地圖只是在某些地區(qū)或特殊要求時(shí)是必須的</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">我們沒有必要全部生成</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">只需生成規(guī)定經(jīng)緯度范圍內(nèi)的某一縮放級(jí)別下的地圖。但即使這樣小縮放級(jí)別下的圖幅數(shù)量仍然不小</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">所以我們應(yīng)該分區(qū)域在不同文件夾下存放。從級(jí)別</SPAN><SPAN lang=EN-US>n</SPAN><SPAN style="FONT-FAMILY: 宋體">到級(jí)別</SPAN><SPAN lang=EN-US>n+1,</SPAN><SPAN style="FONT-FAMILY: 宋體">圖片數(shù)量后者是前者的</SPAN><SPAN lang=EN-US>4</SPAN><SPAN style="FONT-FAMILY: 宋體">倍</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">即放大一個(gè)級(jí)別原級(jí)別一張圖片裂變?yōu)樗膹?lt;/SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">這樣我們可以借鑒四杈樹的組織形式</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">即若樹的深度為</SPAN><SPAN lang=EN-US>N,</SPAN><SPAN style="FONT-FAMILY: 宋體">深度為</SPAN><SPAN lang=EN-US>N-1</SPAN><SPAN style="FONT-FAMILY: 宋體">的節(jié)點(diǎn)子節(jié)點(diǎn)均為</SPAN><SPAN lang=EN-US>30</SPAN><SPAN style="FONT-FAMILY: 宋體">個(gè)</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">其余節(jié)點(diǎn)子節(jié)點(diǎn)為四個(gè)</SPAN><SPAN lang=EN-US>(</SPAN><SPAN style="FONT-FAMILY: 宋體">當(dāng)深度為</SPAN><SPAN lang=EN-US>1</SPAN><SPAN style="FONT-FAMILY: 宋體">時(shí)</SPAN><SPAN lang=EN-US>,</SPAN><SPAN style="FONT-FAMILY: 宋體">根結(jié)點(diǎn)子節(jié)點(diǎn)為</SPAN><SPAN lang=EN-US>5*6=30</SPAN><SPAN style="FONT-FAMILY: 宋體">個(gè)</SPAN><SPAN lang=EN-US>),</SPAN><SPAN style="FONT-FAMILY: 宋體">樹的深度與縮放級(jí)別的對(duì)應(yīng)關(guān)系為</SPAN><SPAN lang=EN-US>N=13-n</SPAN><SPAN style="FONT-FAMILY: 宋體">。</SPAN></P>
<P class=MsoNormal style="MARGIN-LEFT: 21pt; TEXT-INDENT: 21pt"><SPAN style="FONT-FAMILY: 宋體">樹的節(jié)點(diǎn)的命名即為對(duì)應(yīng)文件夾的名稱，根結(jié)點(diǎn)即以縮放級(jí)別命名，葉節(jié)點(diǎn)對(duì)應(yīng)圖片以形如“</SPAN><SPAN lang=EN-US>bx-by.png</SPAN><SPAN style="FONT-FAMILY: 宋體">”的形式命名，其它節(jié)點(diǎn)則是形如“</SPAN><SPAN lang=EN-US>0-0</SPAN><SPAN style="FONT-FAMILY: 宋體">”、“</SPAN><SPAN lang=EN-US>0-1</SPAN><SPAN style="FONT-FAMILY: 宋體">”、“</SPAN><SPAN lang=EN-US>1-0</SPAN><SPAN style="FONT-FAMILY: 宋體">”、“</SPAN><SPAN lang=EN-US>1-1</SPAN><SPAN style="FONT-FAMILY: 宋體">”的形式命名。</SPAN></P>
<P class=MsoNormal style="MARGIN-LEFT: 21pt; TEXT-INDENT: 21pt"><SPAN style="FONT-FAMILY: 宋體">這樣一來生成圖片的時(shí)候就有一個(gè)路徑判斷和生成的問題。在確定了經(jīng)度跨度為【</SPAN><SPAN lang=EN-US>67.5</SPAN><SPAN style="FONT-FAMILY: 宋體">，</SPAN><SPAN lang=EN-US>135</SPAN><SPAN style="FONT-FAMILY: 宋體">】，緯度跨度為【</SPAN><SPAN lang=EN-US>0</SPAN><SPAN style="FONT-FAMILY: 宋體">，</SPAN><SPAN lang=EN-US>56.25</SPAN><SPAN style="FONT-FAMILY: 宋體">】，并且在最小比例尺（縮放等級(jí)為</SPAN><SPAN lang=EN-US>12</SPAN><SPAN style="FONT-FAMILY: 宋體">）之下我們已知圖片是</SPAN><SPAN lang=EN-US>5*6</SPAN><SPAN style="FONT-FAMILY: 宋體">張，即經(jīng)度方向?yàn)?lt;/SPAN><SPAN lang=EN-US>6</SPAN><SPAN style="FONT-FAMILY: 宋體">，緯度方向?yàn)?lt;/SPAN><SPAN lang=EN-US>5</SPAN><SPAN style="FONT-FAMILY: 宋體">，這兩個(gè)值很重要直接影響到我們的命名，當(dāng)然前提變了這個(gè)值也隨著變了。我們制定規(guī)則如下：</SPAN></P>
<P class=MsoNormal style="MARGIN-LEFT: 21pt; TEXT-INDENT: 21pt"><SPAN style="FONT-FAMILY: 宋體">如前樹的深度為</SPAN><SPAN lang=EN-US>N</SPAN><SPAN style="FONT-FAMILY: 宋體">，經(jīng)度方向上的序號(hào)為</SPAN><SPAN lang=EN-US>bx,</SPAN><SPAN style="FONT-FAMILY: 宋體">緯度方向上的序號(hào)為</SPAN><SPAN lang=EN-US>by</SPAN><SPAN style="FONT-FAMILY: 宋體">。則當(dāng)</SPAN><SPAN lang=EN-US>1&lt;N&lt;max(N)</SPAN><SPAN style="FONT-FAMILY: 宋體">時(shí)，經(jīng)度方向上的節(jié)點(diǎn)值</SPAN><SPAN lang=EN-US>Lng</SPAN><SPAN style="FONT-FAMILY: 宋體">＝</SPAN><SPAN lang=EN-US>ToString(((bx-7*N)/6)%2), </SPAN><SPAN style="FONT-FAMILY: 宋體">緯度方向上的節(jié)點(diǎn)值</SPAN><SPAN lang=EN-US>Lat</SPAN><SPAN style="FONT-FAMILY: 宋體">＝</SPAN><SPAN lang=EN-US>ToString((by/5)%2),</SPAN><SPAN style="FONT-FAMILY: 宋體">則節(jié)點(diǎn)名稱命名為</SPAN><SPAN lang=EN-US>Lng+”-”+Lat</SPAN><SPAN style="FONT-FAMILY: 宋體">。</SPAN><BR></P>