crop contour plot compressor map

Hi i created compressor map in matlab and i would like to crop lines outside of my compressor map.I could not find any solution , i used Nan and convhull but the did not work. Please advice me something. i will attach my codes and my plot and desired compressor map Picture.

if   %%Compressor

    for i=1:length(indices)
        [Max_mdot_corr(i),k(i)]=max(mdot_corr(indices{1,i}));
        [Min_mdot_corr(i),k1(i)]=min(mdot_corr(indices{1,i}));
    end
    ind=length(k1)
    for g=1:ind
        indices_speed(g)=indices{1,g}(k1(g))
    end
    for q= 1:ind
        PI_C_tt_speed{q}=(PI_C_tt(indices_speed(q)))
    end

    for s=1:length(k)
        zeilenum_max(s)=indices{1,s}(k(1,s));
        PI_C_tt_comp_max(s)=PI_C_tt(zeilenum_max(1,s));
        zeilenum_min(s)=indices{1,s}(k1(1,s));
        PI_C_tt_comp_min(s)=PI_C_tt(zeilenum_min(1,s));
    end

    %%Vector      
 %mdot_corr=linspace(min(mdot_corr),max(mdot_corr),100)                                                                                                                 
    mdot_corr_vec=mdot_corr(:);
     %PI_C_tt=linspace(min(PI_C_tt),max(PI_C_tt),100)
    PI_C_tt_vec=PI_C_tt(:)
 %eta_c_tt_is=linspace(min(eta_c_tt_is),max(eta_c_tt_is),100)
   eta_c_tt_is_vec=eta_c_tt_is(:);

    %%Pumpgrenze/Stopfgrenze/Drehzahlinien
    hold on
    %%Drehzahllinien
    for j=1:length(indices)
    plot3(mdot_corr(indices{1,j}(1:end)),PI_C_tt(indices{1,j}(1:end)),eta_c_tt_is_hun(indices{1,j}(1:end)),'-bs','Linewidth',1.5,...
    'MarkerEdgeColor','b');

    %%Stopfgrenze
    plot(Max_mdot_corr(1,:),PI_C_tt_comp_max(1,:),'linewidth',2);

    %%Pumpgrenze
    plot(Min_mdot_corr(1,:),PI_C_tt_comp_min(1,:),'linewidth',2);
    %%Wirkungsgradlinien
    Wnodes=40;
    PRnodes=40;
    smooth=1.5;
    [eff_grid,M_grid,P_grid]=gridfit(mdot_corr_vec,PI_C_tt_vec,eta_c_tt_is_vec,Wnodes,PRnodes,'smoothness',smooth);
    tx=linspace(min(mdot_corr),max(mdot_corr),40);
    ty=linspace(min(PI_C_tt),max(PI_C_tt),40);
    eff_grid_text=ceil(eff_grid*100);

link :http://www.bing.com/images/search?q.....rggFgEomfA&ajaxhist=0

[cemsi888]

i found solution on this link :http://www.mathworks.com/matlabcentral/newsreader/view_thread/331932 but i could not implement in my m file. it uses load but i do not Need to use load.here is my code

   outsidecom = ~inpolygon(tx,ty,uslon,uslat);
 Severity_grid(outsidecom) = NaN;
        [C,h]=contour(tx,ty,eff_grid,11)
additionaly above.
i took error massge and says undefined function uslat ..

[Walter Roberson]

And I need immediately sleep.

http://www.mathworks.com/matlabcentral/answers/29922-why-your-question-is-not-urgent-or-an-emergency

[cemsi888]

thanx a lot for your detailed Information. Do not worry i deleted it