How do I solve 'Invalid first data argument'?

Hello, I am currently a university student currently doing a MATLAB coursework assignment. I have produced the following coding as part of the assignment:

Co = 0.0000113125;
V = 400000000;
R = 14000000;
Mo = 4525;
t = 0:1:60;
    Ct = Co + exp((-R/V)*t);
Ct

Cppb = (1000000000*(Ct/1000));
Cppb

figure
plot(Cppb,t,'-r','o','MarkerFaceColor','g','MarkerSize',4)
xlabel('Time (days)');
ylabel('Concertration (ppb)');
title('Lake Chemical Spill Analysis');
legend('Concertration of Chemical in Lake')

And for some reason, it keeps saying 'Invalid first data argument' and I am not sure why. Can someone help? Any help would be appreciated.

Thanks.

Answer 1

[Yu]

The issues is cause by plot command with both '-r' and 'o'. Do you want a red line with green markers? If that this the case, you may want to change the plot line to

plot(Cppb,t,'-o', 'Color', 'r', 'MarkerFaceColor','g','MarkerSize',4)

[Samuel Lotay]

Thanks for the suggestion. I've managed to solve this thanks to a suggestion from one of my friends on my university course. But thanks for the suggestion anyway.