diff options
Diffstat (limited to 'Build/source/utils/asymptote/examples/worldmap.asy')
-rw-r--r-- | Build/source/utils/asymptote/examples/worldmap.asy | 174 |
1 files changed, 87 insertions, 87 deletions
diff --git a/Build/source/utils/asymptote/examples/worldmap.asy b/Build/source/utils/asymptote/examples/worldmap.asy index 59479fffbe2..c52ff23dedc 100644 --- a/Build/source/utils/asymptote/examples/worldmap.asy +++ b/Build/source/utils/asymptote/examples/worldmap.asy @@ -1,87 +1,87 @@ -settings.outformat="pdf";
-size(20cm);
-
-// The required data file is available here:
-// http://www.uni-graz.at/~schwaige/asymptote/worldmap.dat
-// This data was originally obtained from
-// http://www.ngdc.noaa.gov/mgg_coastline/mapit.jsp
-
-real findtheta(real phi, real epsilon=realEpsilon) {
- // Determine for given phi the unique solution -pi/2 <= theta <= pi/2 off
- // 2*theta+sin(2*theta)=pi*sin(phi)
- // in the non-trivial cases by Newton iteration;
- // theoretically the initial guess pi*sin(phi)/4 always works.
- real nwtn(real x, real y) {return x-(2x+sin(2x)-y)/(2+2*cos(2x));};
- real y=pi*sin(phi);
- if(y == 0) return 0.0;
- if(abs(y) == 1) return pi/2;
- real startv=y/4;
- real endv=nwtn(startv,y);
- if(epsilon < 500*realEpsilon) epsilon=500*realEpsilon;
- while(abs(endv-startv) > epsilon) {startv=endv; endv=nwtn(startv,y);};
- return endv;
-}
-
-pair mollweide(real lambda, real phi, real lambda0=0){
- // calculate the Mollweide projection centered at lambda0 for the point
- // with coordinates(phi,lambda)
- static real c1=2*sqrt(2)/pi;
- static real c2=sqrt(2);
- real theta=findtheta(phi);
- return(c1*(lambda-lambda0)*cos(theta), c2*sin(theta));
-}
-
-guide gfrompairs(pair[] data){
- guide gtmp;
- for(int i=0; i < data.length; ++i) {
- pair tmp=mollweide(radians(data[i].y),radians(data[i].x));
- gtmp=gtmp--tmp;
- }
- return gtmp;
-}
-
-string datafile="worldmap.dat";
-
-file in=input(datafile,comment="/").line();
-// new commentchar since "#" is contained in the file
-pair[][] arrarrpair=new pair[][] ;
-int cnt=-1;
-bool newseg=false;
-while(true) {
- if(eof(in)) break;
- string str=in;
- string[] spstr=split(str,"");
-
- if(spstr[0] == "#") {++cnt; arrarrpair[cnt]=new pair[] ; newseg=true;}
- if(spstr[0] != "#" && newseg) {
- string[] spstr1=split(str,'\t'); // separator is TAB not SPACE
- pair tmp=((real) spstr1[1],(real) spstr1[0]);
- arrarrpair[cnt].push(tmp);
- }
-}
-
-for(int i=0; i < arrarrpair.length; ++i)
- draw(gfrompairs(arrarrpair[i]),1bp+black);
-
-// lines of longitude and latitude
-pair[] constlong(real lambda, int np=100) {
- pair[] tmp;
- for(int i=0; i <= np; ++i) tmp.push((-90+i*180/np,lambda));
- return tmp;
-}
-
-pair[] constlat(real phi, int np=100) {
- pair[] tmp;
- for(int i=0; i <= 2*np; ++i) tmp.push((phi,-180+i*180/np));
- return tmp;
-}
-
-for(int j=1; j <= 5; ++j) draw(gfrompairs(constlong(-180+j/6*360)),white);
-draw(gfrompairs(constlong(-180)),1.5bp+white);
-draw(gfrompairs(constlong(180)),1.5bp+white);
-for(int j=0; j <= 12; ++j) draw(gfrompairs(constlat(-90+j/6*180)),white);
-//draw(gfrompairs(constlong(10)),dotted);
-
-close(in);
-shipout(bbox(1mm,darkblue,Fill(lightblue)), view=true);
-
+settings.outformat="pdf"; +size(20cm); + +// The required data file is available here: +// http://www.uni-graz.at/~schwaige/asymptote/worldmap.dat +// This data was originally obtained from +// http://www.ngdc.noaa.gov/mgg_coastline/mapit.jsp + +real findtheta(real phi, real epsilon=realEpsilon) { + // Determine for given phi the unique solution -pi/2 <= theta <= pi/2 off + // 2*theta+sin(2*theta)=pi*sin(phi) + // in the non-trivial cases by Newton iteration; + // theoretically the initial guess pi*sin(phi)/4 always works. + real nwtn(real x, real y) {return x-(2x+sin(2x)-y)/(2+2*cos(2x));}; + real y=pi*sin(phi); + if(y == 0) return 0.0; + if(abs(y) == 1) return pi/2; + real startv=y/4; + real endv=nwtn(startv,y); + if(epsilon < 500*realEpsilon) epsilon=500*realEpsilon; + while(abs(endv-startv) > epsilon) {startv=endv; endv=nwtn(startv,y);}; + return endv; +} + +pair mollweide(real lambda, real phi, real lambda0=0){ + // calculate the Mollweide projection centered at lambda0 for the point + // with coordinates(phi,lambda) + static real c1=2*sqrt(2)/pi; + static real c2=sqrt(2); + real theta=findtheta(phi); + return(c1*(lambda-lambda0)*cos(theta), c2*sin(theta)); +} + +guide gfrompairs(pair[] data){ + guide gtmp; + for(int i=0; i < data.length; ++i) { + pair tmp=mollweide(radians(data[i].y),radians(data[i].x)); + gtmp=gtmp--tmp; + } + return gtmp; +} + +string datafile="worldmap.dat"; + +file in=input(datafile,comment="/").line(); +// new commentchar since "#" is contained in the file +pair[][] arrarrpair=new pair[][] ; +int cnt=-1; +bool newseg=false; +while(true) { + if(eof(in)) break; + string str=in; + string[] spstr=split(str,""); + + if(spstr[0] == "#") {++cnt; arrarrpair[cnt]=new pair[] ; newseg=true;} + if(spstr[0] != "#" && newseg) { + string[] spstr1=split(str,'\t'); // separator is TAB not SPACE + pair tmp=((real) spstr1[1],(real) spstr1[0]); + arrarrpair[cnt].push(tmp); + } +} + +for(int i=0; i < arrarrpair.length; ++i) + draw(gfrompairs(arrarrpair[i]),1bp+black); + +// lines of longitude and latitude +pair[] constlong(real lambda, int np=100) { + pair[] tmp; + for(int i=0; i <= np; ++i) tmp.push((-90+i*180/np,lambda)); + return tmp; +} + +pair[] constlat(real phi, int np=100) { + pair[] tmp; + for(int i=0; i <= 2*np; ++i) tmp.push((phi,-180+i*180/np)); + return tmp; +} + +for(int j=1; j <= 5; ++j) draw(gfrompairs(constlong(-180+j/6*360)),white); +draw(gfrompairs(constlong(-180)),1.5bp+white); +draw(gfrompairs(constlong(180)),1.5bp+white); +for(int j=0; j <= 12; ++j) draw(gfrompairs(constlat(-90+j/6*180)),white); +//draw(gfrompairs(constlong(10)),dotted); + +close(in); +shipout(bbox(1mm,darkblue,Fill(lightblue)), view=true); + |