How can I plot 2D surface plot with color bar

I have an excel file containing 3 variables as attached. I want to plot the variables as a 2D surface plot with the third column representing the color bar. I also attach an example of the plot I am trying to plot.

When I used surf command, I get this error:

Error using surf (line 71)

Z must be a matrix, not a scalar or vector.

Error in PTC_calculation (line 74)

surf(w_ev,beta,PTC)

Thanks

[KSSV]

You cannot plot a surface plot with the data you have.

T = readtable('https://in.mathworks.com/matlabcentral/answers/uploaded_files/1227857/DATA.xlsx') ;
x = T.w ;
y = T.beta ;
z = T.PTC ;
scatter(x,y,[],z)

Answer 1

[Star Strider]

It is possible to create a surface plot from it, however it is probably not worth the effort —

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1227857/DATA.xlsx')

T1 = 202×3 table
        w            beta         PTC  
    __________    __________    _______

    0.00012407        628.76    0.14509
     0.0050855         25773    0.12082
      0.010047         50917    0.13112
      0.015008         76061    0.17144
       0.01997     1.012e+05    0.21571
      0.024931    1.2635e+05    0.25994
      0.029893    1.5149e+05    0.30277
      0.034854    1.7664e+05    0.34359
      0.039816    2.0178e+05    0.38222
      0.044777    2.2693e+05    0.41867
      0.049739    2.5207e+05    0.45304
        0.0547    2.7721e+05    0.48543
      0.059662    3.0236e+05    0.51597
      0.064623     3.275e+05    0.54477
      0.069584    3.5265e+05    0.57192
      0.074546    3.7779e+05    0.59753

figure
stem3(T1{:,1}, T1{:,2}, T1{:,3})
xlabel('w')
ylabel('\beta')
view(60,30)
title('Original Data')

N = size(T1,1)*10;
wv = linspace(min(T1.w), max(T1.w), N);
betav = linspace(min(T1.beta), max(T1.beta), N);
PTCv = linspace(min(T1.PTC), max(T1.PTC), N);

[Wm,Bm] = ndgrid(wv, betav);
PTCm = griddata(T1.w, T1.beta, T1.PTC, Wm, Bm);
PTCm(isnan(PTCm)) = 0;

figure
surf(Wm, Bm, PTCm, 'EdgeColor','interp', 'FaceAlpha',0.5)
colormap(turbo)
colorbar
xlabel('w')
ylabel('\beta')
view(60,30)
title('Interpolated Surface Plot Of Original Data')

figure
surf(Wm, Bm, PTCm, 'EdgeColor','interp', 'FaceAlpha',0.5)
colormap(turbo)
colorbar
xlabel('w')
ylabel('\beta')
view(-15,45)
title('Interpolated Surface Plot Of Original Data')

EDIT — Corrected typograp[hical errors.

.

[Ambali Odebowale]

@Star Strider Thanks for the effort. Though it doesn't really give me the information i need from the graph. I reaaly appreciate your assistance.

[Star Strider]

What information do you need from it?

[Ambali Odebowale]

I want it to look like the attached image (Image.PNG). From which I will be able to see surface mode. The three parameters required to get the plot are contained in the excel file. Do you want me to paste my code, maybe that will help.

Thanks

[Star Strider]

I must have missed that last night when I first saw this.

Use contourf instead of surf —

T1 = readtable('https://www.mathworks.com/matlabcentral/answers/uploaded_files/1227857/DATA.xlsx');

N = size(T1,1)*10;
wv = linspace(min(T1.w), max(T1.w), N);
betav = linspace(min(T1.beta), max(T1.beta), N);
PTCv = linspace(min(T1.PTC), max(T1.PTC), N);

[Wm,Bm] = ndgrid(wv, betav);
PTCm = griddata(T1.w, T1.beta, T1.PTC, Wm, Bm);
PTCm(isnan(PTCm)) = 1E-8;

figure
contourf(Wm, Bm, PTCm)
colormap(turbo)
% colormap(flipud(turbo))
colorbar
xlabel('w')
ylabel('\beta')
title('Interpolated Surface Plot Of Original Data')

figure
contour(Wm, Bm, PTCm)
colormap(turbo)
% colormap(flipud(turbo))
colorbar
xlabel('w')
ylabel('\beta')
title('Interpolated Surface Plot Of Original Data')

This is the best it is possible to do with the supplied data. If you have more data or a different data set, you may get the result you want. My code should work with it without modification, if the variables in the Excel file have the same names and the same positions in the file.

.

[Ambali Odebowale]

Thanks so much....This looks better

[Star Strider]

As always, my pleasure!