[Matlab] show a normal random heart

% Just for fun, not really useful.... % @ http://scriptdemo.blogspot.com  clear; close all; r=0.618; n=10000; re=sqrt(1-r*r); x=normrnd(0,1,n,1); y=x*r+normrnd(0,1,n,1)*re;y(x<0)=-y(x<0); plot(x,y,'o','markerEdgeColor',[1 0 1],'markerFaceColor','none'); axis equal tight off; set(gcf,'MenuBar','none','color','w')

[Matlab] bar/tube plot along a 3d path

function hbarplot=barplot(x,y,z,varargin) % plot a 3d surface/tube centered at (x,y,z) % usage: %           hbarplot=barplot(x,y,z,varargin) %           varargin: %                       'v' : the cdata values, same size as z %                       'n' : N-isogon as the basic shape %                       'r' : radius of the N-isogon %    e.g., %          zz=0:0.5:10; %          hh=barplot(cos(zz/10*pi),5,zz,'v',randn(1,numel(zz))+sin(zz/10*pi),'n',4,'r',sin(zz/10*pi)); view(3) %          http://scriptdemo.blogspot.com clc; myN=3; myR=0.5; isV=0; if nargin>3    while(size(varargin,2)>0)       switch lower(varargin{1})       case {'v','cdata','colordata','facecolordata'}           v=varargin{2};           varargin(1:2)=[];           isV=1;       case {'n','nshape'}           myN=varargin{2};           varargin(1:2)=[];       case {'r','radius'}           myR=varargin{2};           varargin(1:2)=[];       otherwise           error(['Not defined properties!',varargin{1}])       end    end elseif nargin==0    % demo case    zz=0:0.5:10;    hbarplot=barplot(cos(zz/10*pi),5,zz,'v',randn(1,numel(zz))+sin(zz/10*pi),'n',4,'r',sin(zz/10*pi));    view(-150,30);    return elseif nargin<3    help barplot    return end [xx,yy,zz]=getMeshN(x,y,z,myR,myN); if isV==0    hbarplot=surface(xx',yy',zz'); else    if numel(v)==numel(z)       vv=repmat(reshape(v,[],1),1,size(xx,2));    end    hbarplot=surface(xx',yy',zz');    set(hbarplot,'cdata',vv'); end set(hbarplot,'tag','barplot','linestyle','none','facecolor','interp'); axis off equal set(gcf,'color','w'); function [xx,yy,zz]=getMeshN(x0,y0,z,myR,N) if nargin==3    myR=0.5;    N=3; elseif nargin==4    N=3; elseif nargin~=5    error('Usage: [xx,yy,zz]=getMeshN(x,y,z,myR,N)'); end z=reshape(z,[],1); numZ=numel(z); myAng=linspace(0,2*pi,N+1); xslab=cos(myAng); yslab=sin(myAng); %N=numel(xslab)-1; % could be other shape as well. if numel(x0)==1    x0=repmat(x0,numZ,N+1); elseif numel(x0)==numZ    x0=repmat(reshape(x0,[],1),1,N+1); end if numel(y0)==1    y0=repmat(y0,numZ,N+1); elseif numel(y0)==numZ    y0=repmat(reshape(y0,[],1),1,N+1); end if numel(myR)==1    xx=repmat(xslab*myR,numZ,1)+x0;    yy=repmat(yslab*myR,numZ,1)+y0; else    myR=repmat(reshape(myR,[],1),1,N+1);    xx=repmat(xslab,numZ,1).*myR+x0;    yy=repmat(yslab,numZ,1).*myR+y0; end zz=repmat(z,1,N+1);

[Matlab] fill a specific-value region with a given color

function FillIt(lon,lat,Land,FillC,TagType,FillValue) % To fill a specific-value region with a given color % Usage: %            FillIt(lon,lat,Land,FillC,TagType,FillValue) %                   TagType: could be 'RU' or 'LD',  %                                 to fill right-up square or left-down square %                   FillValue: nan [default] or specific value to fill with color [FillC] %            Note: lon, lat, Land must be the same size %      e.g., %            FillIt(lon,lat,lsmask,[0.0 0.3 0.3],'RU') %      http://scriptdemo.blogspot.com if nargin==0    %demo    load topo topo;    topo(topo>0)=nan;    xx=1:360; yy=1:180;    [xx,yy]=meshgrid(xx,yy);    FillIt(xx,yy,topo,[0.4 0.3 0.4],'RU');    set(gca,'tickdir','out','linewidth',2,'xminortick','on','yminortick','on','box','on','fontweight','bold');    set(gcf,'color','w'); axis equal; axis tight;    return end if nargin==3    FillC=[0.3 0.3 0.3];    TagType='RU';    FillValue='nan'; elseif nargin==4    TagType='RU';    FillValue='nan'; elseif nargin==5    FillValue='nan'; elseif nargin~=6    help FillIt;    return end if numel(lon)~=numel(lat)    disp('lon and lat must be the same size')    return end if numel(lon)~=numel(Land)    disp('lon/lat and land must be the same size')    return end [Ny,Nx]=size(Land); if ischar(FillValue)    if strcmpi(FillValue,'nan')       [Indy,Indx]=find(isnan(Land));    else       disp(['invalid fill value: ',FillValue])       return    end elseif isnumeric(FillValue)       [Indy,Indx]=find(Land==FillValue); else       disp('invalid fill value')       return end switch upper(TagType)    case 'RU'       % Right Up       % 4----3       % |      |       % 1----2       Indx(Indy==Ny)=[];Indy(Indy==Ny)=[];       Indy(Indx==Nx)=[];Indx(Indx==Nx)=[];       Fillx(1,:)=lon((Indx-1)*Ny+Indy);       Fillx(2,:)=lon((Indx)*Ny+Indy);       Fillx(3,:)=lon((Indx)*Ny+Indy+1);       Fillx(4,:)=lon((Indx-1)*Ny+Indy+1);       Fillx(5,:)=lon((Indx-1)*Ny+Indy);       Filly(1,:)=lat((Indx-1)*Ny+Indy);       Filly(2,:)=lat((Indx)*Ny+Indy);       Filly(3,:)=lat((Indx)*Ny+Indy+1);       Filly(4,:)=lat((Indx-1)*Ny+Indy+1);       Filly(5,:)=lat((Indx-1)*Ny+Indy);    case 'LD'       % Left Down       % 2----1       % |     |       % 3----4       Indx(Indy==1)=[];Indy(Indy==1)=[];       Indy(Indx==1)=[];Indx(Indx==1)=[];       Fillx(1,:)=lon((Indx-1)*Ny+Indy);Filly(1,:)=lat((Indx-1)*Ny+Indy);       Fillx(2,:)=lon((Indx-2)*Ny+Indy);Filly(2,:)=lat((Indx-2)*Ny+Indy);       Fillx(3,:)=lon((Indx-2)*Ny+Indy-1);Filly(3,:)=lat((Indx-2)*Ny+Indy-1);       Fillx(4,:)=lon((Indx-1)*Ny+Indy-1);Filly(4,:)=lat((Indx-1)*Ny+Indy-1);       Fillx(5,:)=lon((Indx-1)*Ny+Indy);Filly(5,:)=lat((Indx-1)*Ny+Indy);    otherwise      disp('Not defined Fill Type')      help FillIt      return end if ~ishold; hold on; end hf=patch(Fillx,Filly,FillC); set(hf,'linestyle','none','tag','fillIt');

[Matlab] show 2d mesh grid

function ShowGridLine(lon,lat,NSkip,LineC,LineS,LineM) % To show a 2d mesh-grid defined by given grid points % similar to the function mesh? % Example: %          ShowGridLine(lon,lat,2,'k','-','.') %          http://scriptdemo.blogspot.com % if (nargin>3)     if exist('LineC','var')~=1 LineC='k'; end     if exist('LineS','var')~=1 LineS='-'; end     if exist('LineM','var')~=1 LineM='none'; end elseif (nargin>=2)     if exist('NSkip','var')==1         if ischar(NSkip) LineC=NSkip; clear NSkip; end     end     if exist('NSkip','var')~=1 NSkip=5; end     if exist('LineC','var')~=1 LineC='k'; end     if exist('LineS','var')~=1 LineS='-'; end     if exist('LineM','var')~=1 LineM='none'; end elseif (nargin==0)     close all;     [xx,yy]=meshgrid(1:19,1:19);     ShowGridLine(xx,yy,1,'k','-');     plot(4,4,'o','markerfacecolor','k','markersize',4,'markeredgecolor','k');     plot(16,16,'o','markerfacecolor','k','markersize',4,'markeredgecolor','k');     plot(4,16,'o','markerfacecolor','k','markersize',4,'markeredgecolor','k');     plot(16,4,'o','markerfacecolor','k','markersize',4,'markeredgecolor','k');     set(gcf,'color','w');     set(gca,'xtick',2:2:18,'ytick',2:2:18,'ydir','r','xaxislocation','top')     axis equal; axis tight;     xlabel('Go Board','fontweight','bold','fontsize',18,'color','red');     return else     help ShowGridLine     return end [N1,N2]=size(lat); if ~ishold hold on; end for NL=1:NSkip:N2     hp=plot(lon(:,NL),lat(:,NL));     set(hp,'color',LineC,'linestyle',LineS,'Marker',LineM) end for NL=1:NSkip:N1     hp=plot(lon(NL,:),lat(NL,:));     set(hp,'color',LineC,'linestyle',LineS,'Marker',LineM,'tag','gridLines') end

Demo:

[Matlab] create a time series using datenum

function myT=yymmdd2x(inYear,inMonth,inDay) % create the time axis based on input time [year, mon, date], using datenum % usage: %           xTime=yymmdd2x(years, months, days); % or %           xTime=yymmdd2x(yyyymmdd); %  http://scriptdemo.blogspot.com if (nargin==0 || nargin>3)    help yymmdd2x;    return end if nargin==1    %yyyymmdd case    yyyymmdd=inYear;    inYear=floor(yyyymmdd/10000);    inDay=mod(yyyymmdd,100);    inMonth=floor(mod(yyyymmdd,10000)/100); clear yyyymmdd    totalDaysInYear=datenum(inYear+1,1,1)-datenum(inYear,1,1);    daysInYear=datenum(inYear,inMonth,inDay)-datenum(inYear,1,1)+1;    myT=daysInYear./totalDaysInYear+inYear; elseif nargin==2    % no date, set to 15th, may consider create 12 month for each year if necessary    if length(inYear)~=length(inMonth) && length(inMonth)<=12       % repeat inMonth for each year       inMonth=reshape(inMonth,1,[]);       mm=repmat(inMonth,1,length(inYear));       yy=reshape(repmat(reshape(inYear,1,[]),length(inMonth),1),1,[]);       clear inMonth inYear       totalDaysInYear=datenum(yy+1,1,1)-datenum(yy,1,1);       daysInYearA=datenum(yy,mm+1,1)-datenum(yy,1,1)+1;       daysInYear=datenum(yy,mm,1)-datenum(yy,1,1)+1;       myT=0.5*(daysInYearA+daysInYear)./totalDaysInYear+yy;    elseif (length(inYear)==length(inMonth))       totalDaysInYear=datenum(inYear+1,1,1)-datenum(inYear,1,1);       daysInYearA=datenum(inYear,inMonth+1,1)-datenum(inYear,1,1)+1;       daysInYear=datenum(inYear,inMonth,1)-datenum(inYear,1,1)+1;       myT=0.5*(daysInYearA+daysInYear)./totalDaysInYear+inYear;    else        disp('Too difficult for me to guess what your wanna to do...')        return    end else    totalDaysInYear=datenum(inYear+1,1,1)-datenum(inYear,1,1);    daysInYear=datenum(inYear,inMonth,inDay)-datenum(inYear,1,1)+1;    myT=daysInYear./totalDaysInYear+inYear; end

[Processing] spiral demo using Processing

//@ http://scriptdemo.blogspot.com float myAngle, myScale, myAlpha0, myAlpha; float shiftX, shiftY; int rr,gg,bb; // to control the shape of spiral float minScale, dAngle, coefScale; boolean isLine=false; boolean isColor=true; void setup() {   size(500,500);   shiftX=width/2;   shiftY=height/2;   myAngle=0;   myScale=1.0;   minScale=0.01;   coefScale=0.99;   myAlpha0=8;   dAngle=PI/50;   noStroke();   background(255);   frameRate(30);   smooth(); } void draw() {    while(myScale>minScale)    {       pushMatrix();       myAngle=myAngle+dAngle;       myScale=myScale*coefScale;       translate(shiftX,shiftY);       rotate(myAngle);       scale(myScale);       if (isColor)       {          rr=ceil(255*sin(myAngle));          gg=ceil(255*cos(myAngle));          if (rr<=0) rr=rr+255;          if (gg<=0) gg+=255;          bb=(rr+gg)%256;       } else {         rr=10; gg=10; bb=10;         if (isLine) myAlpha0=max(myAlpha0,20);       }       myAlpha=min(myAlpha0*(ceil(myAngle/TWO_PI)),255);       if (isLine)       {         stroke(rr,gg,bb,myAlpha);         noFill();         line(-1*shiftX,shiftY,shiftX,shiftY);       } else {         noStroke();         fill(bb,gg,rr,myAlpha);         rect(-1*shiftX,shiftY,width,height);       }       popMatrix();    } } void mouseClicked() {   isLine=!isLine;   myAlpha=myAlpha0;   myScale=1;   myAngle=random(-PI,PI);   background(255); } void mouseDragged() {    isColor=!isColor;    myAlpha=myAlpha0;    myScale=1;    myAngle=random(-PI,PI);    background(255); }

png2eps: convert png image to eps with high resolution

#!/bin/bash # convert a png file into eps file # Usage: #           png2eps pngfile.png [-q JPGQuality -r FigResizePercentage] # e.g., #           png2eps aa.png bb.png -q 100 -r 60 # http://scriptdemo.blogspot.com if [ $# == 0 ]; then    sed -n '3,6p' png2eps    exit fi JPGQuality='100' FileResize='80' nfile=0 while test -n "$1" do   case "$1" in     -q|-quality)        JPGQuality=$2        shift        ;;     -r|-resize)        FileResize=$2        shift        ;;     *)        if [ -e $1 ]; then           pngfiles[$nfile]=$1           nfile=`expr $nfile + 1`        fi        shift        ;;   esac done for pngfile in ${pngfiles[*]} do   #convert to jpg file first to keep high resolution   jpgfile=${pngfile%%.*}.jpg   epsfile=${pngfile%%.*}.eps   eval "convert -quality ${JPGQuality} -resize ${FileResize}% ${pngfile} ${jpgfile}"   [ -e ${epsfile} ] && epsfile=tmp_${epsfile}   eval "convert ${jpgfile} eps3:${epsfile} && rm -f ${jpgfile}" done

Another solution is to use png2pnm and pnm2ps commands:

#!/bin/bash # convert a png file into eps file [using pngtopnm, pnmtops] # Usage: #           png2eps2 pngfile.png -scale reScale [-o outfile.eps] # e.g., #           png2eps2 aa.png -scale 0.3 -o aa.eps # http://scriptdemo.blogspot.com if [ $# == 0 ]; then    sed -n '3,6p' png2eps2    exit fi reScale='0.3' nfile=0 while test -n "$1" do   case "$1" in     -s|-r|-scale|-rescale)        reScale=$2        shift        ;;     -o|-output)        epsfile=$2        shift        ;;     *)        if [ -e $1 ]; then           pngfiles[$nfile]=$1           nfile=`expr $nfile + 1`        fi        shift        ;;   esac done for pngfile in ${pngfiles[*]} do   #convert to jpg file first and resize   [ ! -n "$epsfile" ] && epsfile=${pngfile%%.*}.eps   [ $nfile -gt 1 ] && epsfile=${pngfile%%.*}.eps   [ -e ${epsfile} ] && epsfile=tmp_${epsfile}   eval "pngtopnm ${pngfile} | pnmtops -noturn -nocenter -scale ${reScale} - >${epsfile}"   eps2eps -dLanguageLevel=3 ${epsfile} thisTmp${epsfile} && mv thisTmp${epsfile} ${epsfile} done

[Processing] More Perlin Noise demo with Processing

Actually it is generated with the Perlin Noise Particle System from Dann Van Hasselt (http://www.openprocessing.org/visuals/?visualID=10475) What I did is set the initial particle position in every loop (within draw()): e.g.,             myt=elapseFrames/10/TWO_PI;            pos.x=0.5*width +(1-sin(myt))*cos(myt)*0.2*width;            pos.y=0.5*height-(1-sin(myt))*sin(myt)*0.2*height; Also you can change the color and particle details to get something like (online): or a colourful one:

Perlin Noise demo with Processing

#copyright @ http://scriptdemo.blogspot.com // inspired by the Perlin Noise Particle System from Daan van Hasselt (http://www.openprocessing.org/visuals/?visualID=10475) // I recoded it with more additional features. Also it may be easier to understand without the class. // Online test  from my dropbox (my Dropbox reference link) float myw=400.0; float myh=350.0; float x, y; float u=0; float v=0; float x0, y0, dx, dy; float coefx, coefy, coefz; boolean isAlive=false; boolean isColor=true; boolean isSmooth=true; boolean isLoop=true; int NumP=400; float Npi; void setup() {   Npi=2.3; coefx=0.009; coefy=0.011; coefz=0.0013;   size(floor(myw),floor(myh));   background(255,255,255);   if (isSmooth) smooth(); } void draw() {   for (int n=0; n<=NumP; n++)   {       if (isAlive)       {         float nv=noise(x*coefx,y*coefy,frameCount*coefz);         if (isColor)         {            float mysin=sin((nv-0.3)*TWO_PI*Npi);            float mycos=cos((nv-0.3)*TWO_PI*Npi);            if (mycos>=0 & mysin >=0) fill(floor(abs(mysin)*255),floor(abs(mycos)*255),0,10);            if (mycos>=0 & mysin <0) fill(floor(abs(mysin)*255),0,floor(abs(mycos)*255),10);            if (mycos<0 & mysin >=0) fill(0,floor(abs(mycos)*255),floor(abs(mysin)*255),10);            if (mycos<0 & mysin <0) fill(floor(abs(mysin)*255),floor(abs(mycos)*255),0,10);         } else {            fill(10,10);         }          u=u+cos((nv-0.3)*TWO_PI*Npi);          v=v+sin((nv-0.3)*TWO_PI*Npi);          u=u/2;          v=v/2;          x=x+u;          y=y+v;       } else {         x0=0.5*myw;         y0=0.5*myh;         x=x0; y=y0;         dx=100*frameCount/2000+50;         dy=dx;         isAlive=true;       }       noStroke();       ellipse(x,y,1,1);   }   if (x>width || y> height || x <0 || y< 0) isAlive=false; } void mouseClicked() {   isLoop=!isLoop;   if (!isLoop)   {      noLoop();   } else {      loop();   } }

Here are some demo videos: