I am getting Error using pcolor? What could be the issue

This is the code

clear 
close all 
load('Data.mat'); 
ts=MOM_SPC.ts; 
Az=MOM_SPC.header.az; 
range=MOM_SPC.header.ngs; 
Va=MOM_SPC.header.va; 
deltaR=MOM_SPC.header.dR; 
Range=(1:range).*deltaR/1000; 
M=MOM_SPC.header.nfft; 
m=1:M; 
az=1:Az;
c=3*10^8; 
f=3*10^9; 
lambda=c/f; 
Ts=(2*Va)/lambda;
Pt=(Ts/M).*(sum(abs(ts(m)).^2)); 
Zt=10*log10(Pt) + 20.*log10(Range(az));
Rt=(1/(M-1).*(sum((conj(ts(1:M-1)).*(ts(2:M)))))); 
Vrt=-(lambda/(4*pi*Ts)).*(angle(Rt));
Sf=(abs(fliplr(fftshift(fft(ts(m)))))).^2*(Ts/M); 
Pf=1/M.*sum(Sf); 
Zf=10*log10(Pf) + 20.*log10(Range(az));
Sn=Sf/(sum(Sf)); 
[peak,km]=max(Sn); A=0;
for k= (km-(M/2)):(km+(M/2)-1) 
    mod_index=mod(k,M); 
    if mod_index==0 
        mod_index=M; 
    end
    A= A+ k*Sn(mod_index);
end
Vrf=(A-(M/2))*(lambda/(2*M*Ts));
x =(sin(az.*pi/180))'.*Range; 
y =(cos(az.*pi/180))'.*Range;
figure; pcolor(x,y,Zt); shading flat; title('Radar Reflectivity,Z (dB) in Time Domain');
figure; pcolor(x,y,Vrt); shading flat; title('Radial Velocity Vr (m/s) in Time Domain');
figure; pcolor(x,y,Zf); shading flat; title('Radar Reflectivity,Z (dB) in frequency Domain');
figure; pcolor(x,y,Vrf); shading flat; title('Radial Velocity Vr (m/s) in frequency Domain');

[Geoff Hayes]

Oluwafunmilayo - what is the error message? Please copy and paste the full error message to this question.

[Oluwafunmilayo Williams]

Error using pcolor (line 58) Color data input must be a matrix.

Error in project (line 49) Pcolor (x,y,Zt);

Answer 1

[Prasanna]

Hi,

The error you're encountering, "Color data input must be a matrix," indicates that the dimensions of x, y, and the data you're trying to plot ‘(Zt, Vrt, Zf, Vrf)’ do not align in a way that allows “pcolor” to interpret them as a grid of color values.

For “pcolor” to work, x, y, and the data matrix must all be of the same size, forming a complete grid. To fix the same, you can ensure ‘Range’, ‘az’ and the dimensions of plotting variables ‘(Zt, Vrt, Zf, Vrf)’ are correct. “pcolor” cannot be made from scattered points, it essentially takes a matrix as input.

For more information on pseudocolor plots, refer the following documentation: https://www.mathworks.com/help/matlab/ref/pcolor.html

Hope this helps.