Question

虽然我能够绘制我的FFT（快速傅里叶变换）图（X，Y），但是我无法将我的拟合线f（x）与我的FFT一起绘制。从曲线拟合工具收集方程式，我采用十个最佳拟合并平均得出方程f（x）。

我必须做什么才能用log（freq）和log（Pow）绘制f（x）

代码：

row=69;
col=69;

colormap gray
whitebg('black')

iterations=10^3;


Next=zeros(row,col);
laplacian=zeros(row,col);
critical=zeros(row,col);

B= zeros(row,col);
lums=zeros(1000);


flw=0.5;

u=0.1;

crit=5;
%bns=200;
bns=1000;

for k=1:iterations
    B=B+(rand(row,col)-0.5);
   Next=B;

rns=5.;
for i=1:row
for j=1:col

rfromns=(col+rns-j);
        critical(i,j)=0;
        if i<=2 left=row; else left=(i-1);end
        if i==row right=1; else right=(i+1);end
        if (j<=2) top=1; else top=(j-1);end
        if (j==col) bottom=j; else bottom=(j+1);end
        l=B(i,top)+B(left,j)+B(right,j)+B(i,bottom)+0.5*(B(left,top)+B(right,top)+B(left,bottom)+B(right,bottom));
        l=l-6.*B(i,j);
        laplacian(i,j)=l;
        bfromns=bns/rfromns^3;
        if (abs(l)/((abs(B(i,j))+bfromns)+0.01))>crit; critical(i,j)=1; end
        %if abs(l)>crit; critical(i,j)=1; end
end
end



            for j = 1:col
            if (j==col) lum=0.;end
            for i = 1:row

            if (j>1) Next(i,j)=(1-flw)*B(i,j)+flw*B(i,j-1); end;
            if (j==1) Next(i,j)=(1-flw)*B(i,j); end;

            if (critical(i,j)==1)&& (j>1)   Next(i,j)=B(i,j)*(1-flw-flw*u)+flw*B(i,j-1)+(flw*u)*B(i,j)/5.; end;
            if i<2 left=row; else left=(i-1);end
            if i==row right=1; else right=(i+1);end
            if (j<=2) top=1; else top=(j-1);end
            if (j==col) bottom=j; else bottom=(j+1);end

            if (critical(left,j)==1) Next(i,j)=Next(i,j)+flw*u*B(left,j)/5.;end
            if (critical(right,j)==1) Next(i,j)=Next(i,j)+flw*u*B(right,j)/5.;end
            if (critical(i,top)==1) Next(i,j)=Next(i,j)+flw*u*B(i,top)/5.;end
            if (critical(i,bottom)==1) Next(i,j)=Next(i,j)+flw*u*B(i,bottom)/5.;end

            if (j==col) lum=lum+u*B(i,j)*B(i,j)+abs(laplacian(i,j)); end
            end
            end

lums(k)=lum;

B=Next;                
%Matplot(B)
%if (k>00)
surf(B);
%plot(lums)
%view([0 90])
%pause(0.001)
%end
end


c=fft(lums(129:iterations));
pow=abs(c).^2;
pow=pow(2:(iterations-128)/2);
freq=(2:(iterations-128)/2);

X=log(freq);
Y=log(pow);

%x=length(X);

x=0.6:.1:6.;

%Linear model Poly2
a1 = -0.155;  
a2 = 0.2154;  
a3 = 15.1;
af(x) = a1*x.^2 + a2*x + a3;

%Linear model Poly3
b1 = 0.01805;  
b2 = -0.3687;  
b3 = 0.9874;  
b4 = 14.29; 
bf(x) = b1*x.^3 + b2*x.^2 + b3*x + b4;


%General model Power2
c1 = -0.09124;  
c2 = 2.179;  
c3 = 15.34;
cf(x) = c1*x.^c2+c3;


%General model Rat02
d1 = 727.3;  
d2 = -3.447;  
d3 = 51.6; 
df(x) = (d1) / (x.^2 + d2*x + d3);


%General model Gauss1
e1 = 15.01;  
e2 = 1.346;  
e3 = 8.152; 
ef(x) =  e1*exp(-((x-e2)/e3).^2);


%General model Gauss2 
w1 =  1.737;  
w2 =  3.46;
w3 =  2.333;  
w4 =  30.03;  
w5 =  -23.14;
w6 =  28.23;
wf(x) =  w1*exp(-((x-w2)/w3).^2) + w4*exp(-((x-w5)/w6).^2); 


%General model Sin1
g1 = 15.11;  
g2 = 0.1526;  
g3 = 1.428;  
gf(x) =  g1*sin(g2*x+g3);



%Linear model Poly4
h1 =  0.0179;  
h2 =  -0.252;  
h3 =  1.047;  
h4 =  -1.97; 
h5 =  16.23;  
hf(x) = h1*x.^4 + h2*x.^3 + h3*x.^2 + h4*x + h5;


%General model Fourier1
m1 =  11.05;  
m2 =  3.31;  
m3 =  2.104;  
m4 =  0.3644;  
mf(x) =  m1 + m2*cos(x*m4) + m3*sin(x*m4);


%Linear model
p1 =  0.815;
p2 =  0.1061;
p3 =  8.904;
pf(x) = p1*(sin(x-pi)) + p2*((x-10).^2) + p3;


f(x)=(af(x)+bf(x)+cf(x)+df(x)+ef(x)+wf(x)+gf(x)+hf(x)+mf(x)+pf(x))/10;



plot(X,Y)
plot(f(x))

Answer 1

Matlab / Octave因此使用hold关键字。

如果要在一个图表上绘制多个内容，可以使用hold on启动程序，然后执行一个或多个绘图命令，并使用hold off完成。

示例：

hold on;
x = -10:0.1:10;
plot (x, sin (x));
plot (x, cos (x));
hold off;

文档：https://www.gnu.org/software/octave/doc/interpreter/Manipulation-of-Plot-Windows.html

正如文档所描述的那样，plot通常会调用newplot命令，删除之前的绘图结果，并hold on;阻止此类行为。

在同一图/ matlab上绘制两个不同的方程

1 个答案: