qgis與圖幅實踐
阿新 • • 發佈：2018-11-30
目標：製作以標準圖幅為背景的shp檔案，圖幅由網格組成，網格內顯示圖幅號
成果：
方法：
1、首先生成圖幅座標檔案csv，見程式碼片段；
2、通過qgis，載入csv圖層；
3、qgis:向量->研究工具->網格，按照左上角、右下角的座標，間隔度，生成網格；
4、這裡已經初見效果，為了更好操作，可以疊加融合處理，qgis:向量->地學處理工具->聯合，合併兩圖層(正在試驗)
生成圖幅左上角位置程式碼：
# -*- coding: utf-8 -*- #!/usr/local/bin/python import math meshRow = "A,B,C,D,E,F,G,H,I,J,K,L,M,N".split(",") meshList = [43,44,45,46,47,48,49,50,51,52,53] meshCode = {"B": 4, "C": 16, "D": 144, "E": 576, "F": 2304,"E":9216} meshDeLan = 6.0 #0.0625 meshDeLat = 4.0 #0.0416666666667 #72,138,0,56 #3/2 def getMesh100W(): meshs = {}; for i in range(len(meshRow)): for j in range(len(meshList)): topLeft = ((meshList[j]-1) * meshDeLan - 180, (i+1) * meshDeLat) meshs[meshRow[i] + str(meshList[j])] = topLeft return meshs; def getMeshCode(code): meshs100W = getMesh100W() meshNum = int(math.sqrt(meshCode[code])) meshs = {} for m,topLeft in meshs100W.items(): lngD = meshDeLan / meshNum latD = meshDeLat / meshNum for i in range(meshNum): for j in range(meshNum): s = m + code + str(i + 1).rjust(3,'0') + str(j + 1).rjust(3,'0') meshs[s] = (topLeft[0]+lngD*j+lngD/2, topLeft[1]-latD*i-latD/2) return meshs; if __name__ == "__main__": f = open("meshListF.csv","w") meshs = getMeshCode("F") f.write("mesh,lan,lat\n") for k,v in meshs.items(): f.write(k+","+str(v[0])+","+str(v[1])+"\n")
JavaScript程式碼：想用高德sdk自定義圖層呢，太慢，需要優化
<html> <head> <meta charset="utf-8"> <meta http-equiv="X-UA-Compatible" content="IE=edge"> <meta name="viewport" content="initial-scale=1.0, user-scalable=no, width=device-width"> <title>自定義圖層</title> <link rel="stylesheet" href="https://cache.amap.com/lbs/static/main1119.css"/> <script src="https://webapi.amap.com/maps?v=1.4.10&key=自己申請"></script> <script type="text/javascript" src="https://cache.amap.com/lbs/static/addToolbar.js"></script> <script type="text/javascript" src="mesh.js"></script> </head> <body> <div id="container"></div> <script type="text/javascript"> var map, canvas, context; // create(); //自定義圖層 function create() { map = new AMap.Map('container', { center: [116.306206, 39.975468], zoom:8 }); map.plugin(['AMap.CustomLayer'], function() { canvas = document.createElement('canvas'); canvas.width = map.getSize().width; canvas.height = map.getSize().height; context = canvas.getContext('2d'); var cus = new AMap.CustomLayer(canvas, { zooms: [5, 8], zIndex: 12 }); cus.render = onRender; cus.setMap(map); }); } var meshRow = "A,B,C,D,E,F,G,H,I,J,K,L,M,N".split(","); var meshList = [43,44,45,46,47,48,49,50,51,52,53]; var meshCode = {"B": 4, "C": 16, "D": 144, "E": 576, "F": 2304}; var meshDeLat = 4; var meshDeLan = 6; var meshs = []; function onRender() { context.clearRect(0, 0, canvas.width, canvas.height) if (map.getZoom() < 8){ meshs = getMesh100W(); }else{ meshs = getMeshCode("C"); } for(m in meshs){ drawMesh(map, m, meshs[m]); } } function getMesh100W() { meshs = []; for (i = 0; i< meshRow.length; i++) { for (j = 0; j< meshList.length; j++) { var topLeft = new AMap.LngLat((meshList[j]-1) * meshDeLan - 180, (i+1) * meshDeLat); var downRight = new AMap.LngLat(meshList[j] * meshDeLan - 180, i * meshDeLat); meshs[meshRow[i] + meshList[j]] = new AMap.Bounds(topLeft, downRight); } } return meshs; } function getMeshCode(code) { var meshs100W = getMesh100W(); var meshNum = Math.sqrt(meshCode[code]); meshs = []; for (m in meshs100W) { var topLeft = meshs100W[m].getSouthWest(); var downRight = meshs100W[m].getNorthEast(); var lngD = (downRight.getLng() - topLeft.getLng()) / meshNum; var latD = (topLeft.getLat() - downRight.getLat()) / meshNum; for (i=0; i< meshNum; i++){ for (j=0; j< meshNum; j++){ s = m + code + meshName((i + 1),3) + meshName((j + 1),3); meshs[s] = new AMap.Bounds(new AMap.LngLat(topLeft.getLng()+lngD*j, topLeft.getLat()-latD*i), new AMap.LngLat(topLeft.getLng()+lngD*(j+1), topLeft.getLat()-latD*(i+1))); } } } return meshs; } function drawMesh(map, name, bound) { var gps = [bound.getSouthWest(), bound.getNorthEast(), bound.getCenter()]; AMap.convertFrom(gps, 'gps', function (status, result) { if (result.info === 'ok') { var lnglats = result.locations; var topLeft = map.lngLatToContainer(lnglats[0]); var downRight = map.lngLatToContainer(lnglats[1]); var center = map.lngLatToContainer(lnglats[2]); context.font="15px Verdana"; context.fillStyle="#ff0000"; context.strokeStyle="#FF0000"; context.strokeRect(topLeft.x, topLeft.y, downRight.x - topLeft.x, downRight.y - topLeft.y); context.fillText(name, center.x, center.y); } }); } function meshName(num, formNum){ name = "000000" + num; return name.substr(name.length - formNum); } </script> </body> </html>
qgis:適量網格
參考連線：
https://blog.csdn.net/u012130706/article/details/76285650
https://www.cnblogs.com/gispathfinder/p/6087558.html