[scilab-Users] Problem with the function Graypolarplot

[Antoine Monmayrant]

Le 23/04/12 15:06, solmyr a écrit :
> Hi,
>
> I need to build an angular sound cartography. For this, I have a row vector
> called "theta" for the value of the angle, a row vector called "r" for the
> value of radius. I also have a matrix of size [theta, r] in which are placed
> the values of sound level in dB(A). I found the function graypolarplot very
> good for that but I guess there's a problem of scale of colour...
> I tried the example of the documentation and it works well. I tried to use
> this example like base to build my own map but when I put my matrix in place
> of the original function, the scale of colormap is totally wrong...
> For example, my scale goes from 59 to 83 dB(A) and the colours displayed are
> from 60 to 70 dB(A)...
> I can copy and paste my code for you try it and tell me if you have the same
> problem.
> Thanks by advance !
>
>
> ///Background value of noise (dB(A))
> Lbdf=46;
>
> //Matrix values in dB(A), each line represents the radius
> z0=[80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5 80.5
> 80.5 80.5 80.5];
> z1=[75.5 74.5 73.1 72.5 73.1 79.6 73.1 74.1 74.6 75.5 75.5 76.3 77.9 79.3
> 78.3 78.7 75.5];
> z2=[72.5 70 71 68.5 68.5 68.6 70 70 70.9 72.4 71.8 71.8 73.3 73 73 73.1
> 72.5];
> z3=[70 67.6 67.3 65.4 65.7 66.1 67.9 67 68 68.5 68.9 70.2 69.8 70.5 70.1
> 69.9 70];
> z4=[67.6 66.5 66.1 64.2 64 67.5 65.3 65.1 67 66.6 66 65.8 66.5 67 67.3 67.4
> 67.6];
> z5=[66.5 64.9 63.9 63.3 61.8 61.5 62.7 63.9 63.7 64.9 64.6 67.8 64.8 65.1
> 68.1 66.7 66.5];
>
> //Values of discretization
>      theta=(0:%pi/8:2*%pi); //Basic discretization for the angle
>      thetai=(0:%pi/64:2*%pi); //Thin discretization to smooth the map for the
> angle
>      r=(0:5); //Basic discretization for the radius
>      ri=(0:0.1:5); //Thin discretization to smooth the map for the radius
>
> //Smoothing of the matrix, I will simplify this later...
>
>      d0=splin(theta,z0);
>      z0i=interp(thetai,theta,z0,d0);
>
>      d1=splin(theta,z1);
>      z1i=interp(thetai,theta,z1,d1);
>
>      d2=splin(theta,z2);
>      z2i=interp(thetai,theta,z2,d2);
>
>      d3=splin(theta,z3);
>      z3i=interp(thetai,theta,z3,d3);
>
>      d4=splin(theta,z4);
>      z4i=interp(thetai,theta,z4,d4);
>
>      d5=splin(theta,z5);
>      z5i=interp(thetai,theta,z5,d5);
>
>      Z=[z0i' z1i' z2i' z3i' z4i' z5i'];
>
>      for i=1:length(Z(:,1))
>          d(i,:)=splin(r,Z(i,:));
>          Zi(i,:)=interp(ri,r,Z(i,:),d(i,:));
>      end
>
> //Removing background noise to the smooth noise matrix
>
>      Lz=floor((20*log10(10^(Zi/20)-10^(Lbdf/20)))*10)/10;
>
> //Variables for the mapping
>
>      zmin=min(Lz);
>      zmax=max(Lz);
>      nz=floor((zmax-zmin)/0.1); //This is for the resolution
>
>      h=jetcolormap(nz); //Creation of the colormap
>
> //Display of the result
>
>      clf()
>      graypolarplot(thetai,ri,Lz)
>      xset('colormap',h)
>      colorbar(floor(zmin), floor(zmax+1))
>      title('Angular Noise Cartography','fontsize',3)/
>
> --
> View this message in context: http://mailinglists.scilab.org/Problem-with-the-function-Graypolarplot-tp3932414p3932414.html
> Sent from the Scilab users - Mailing Lists Archives mailing list archive at Nabble.com.
Got it!
It's a bug in the function graypolarplot (I think!).

Just add this at the end of your script:

h=gcf();
h.children(2).children.children(35).cdata_mapping="scaled";

and you'll get fancy colors!
The problem is that the way data is mapped (ie translated into color) is 
not "scaled" but "direct" whereas it's "scaled" in the colorbar.

Antoine