# New help in contourf matlab

1. Feb 12, 2015

### eahaidar

%gamma=20;
gamma=580;
%P=0.1;
P=0.75;
N=P.*gamma;
lamdazero=1550;
[lamdapump,lamdasignal] = meshgrid(1550:0.1:1700,1550:0.1:1700);
beta3=1.3;
beta4=-8*10^-4;
%beta3=0.06;
%beta4=-2*10^-4;
c=2*pi*3*10^8;
%L=1;
L=0.01;
A0=(1./lamdapump) -(1./lamdazero);
B0=(1./lamdapump) -(1./lamdasignal);
%Linearmismatch=beta2.*c.^2.*(B0).^2;
%beta2=(6*pi.*10^5.*beta3.*A0) +(0.5.*beta4.*A0.^2).*(6.*pi.*10^5)^2;
%Second0=(1./2).*beta2.*(c.^2).*(B0.^2);
Third0=10^-9.*beta3.*(c.^3).*A0.*(B0.^2);
Fourth0=10^-12.*beta4.*(1./2).*c.^4.*(A0.^2).*(B0.^2);
%S4=(10^-12/12).*beta4.*c.^4*(B0.^4);
Fourorder=(10^-12).*c.^4.*beta4.*(1/12).*(B0).^4;
g0=1.1*10^-11;
Aeff=11*10^-12;
PSBS=0.025;
%g0=3.9*10^-9;
%Aeff=14*10^-12;
%PSBS=0.005;
SBS=(g0.*PSBS.*1000)./Aeff ;
deltabeta=Third0+Fourth0+Fourorder;
hold on
for i=1:1:length(deltabeta)
for j=1:1:length(deltabeta)
if(deltabeta(i,j)>=0 || deltabeta(i,j)<=(-4*N))
test(i,j)=NaN;
else
test(i,j)=deltabeta(i,j);
end
end
end
contourf(lamdapump,lamdasignal,test,'ShowText','off');
cmap=[0,0,0];
colormap=cmap;
colorbar
h = colorbar;
set(get(h,'title'),'string','\Delta \beta (\gamma P)');
ax = findobj('type','axes');
%set(ax(1),'ytickl',{'-5172.4', '-4310.3', '-3448.3', '-2586.2', '-1724.1',' -862.1', '0', '862.1', '1724.1'})
xlabel('\lambda_p_u_m_p')
ylabel('\lambda_s_i_g_n_a_l')
title('Contour representing linear phase mismatch for FWM pump power 75 mW and SBS pump power 25 mW ')

Hello everyone I am new here and have small experience with matlab and would like some help. So when you execute this code you would see a curve I want this curve to be one color only. Any help with that? Because I would love to retain the original plot without removing points to get that curve. One more thing, I was wondering that if I want to add a condition or in other words a black color (since no black is in my color bar) like if deltabeta=-2 gamma P make deltabeta black colored is it possible Sorry for making you guys read that long. Thank you and looking forward to reading your reply. el-abed

2. Feb 15, 2015

### kreil

For starters, you make built-in MATLAB functions into variables in several places here.

Code (Text):
gamma=580;
colormap=cmap;
Both of these commands will override the MATLAB built-in functions. Don't do this, just use different variable names that don't conflict.

Once you use different variable names, you can set the colormap to whatever you want.

http://www.mathworks.com/help/matlab/ref/colormap.html