log base 10 plot

Good day,

I am trying to figure out why there is no line plotted on my graph once this script is run. I tried playing around with the axis thinking that maybe that was why I wasn't seeing anything plotted; however, this did not resolve my issue.

Is there an error in this code/axis that is preventing it from showing a plot on the graph?

Thank you for your assistance!

Co = 2.666;
C1 = - 2.769; 
C2 = - 0.06247;
C3 = 2.676;
C4 = 0.06411;
C5 = - 4.994;
C6 = 0.181;
C7 = 5.374;
C8 = - 0.4159;
C9 = - 2.715;
C10 = - 0.05814;
C11 = 0.6429;
C12 = 0.208;
C13 = - 0.1394;


Ps_ko = - 0.1239;
Ps_k1 = 0.8705;

for Z = 0.0553: 0.01: 40

U_Ps = Ps_ko + Ps_k1*(log10(Z));

Y_Ps = Co + C1*U_Ps + C2*U_Ps^2 + C3*U_Ps^3 + C4*U_Ps^4 + C5*U_Ps^5 + C6*U_Ps^6 + C7*U_Ps^7 + C8*U_Ps^8 + C9*U_Ps^9 + C10*U_Ps^10 ...
    + C11*U_Ps^11 + C12*U_Ps^12 + C13*U_Ps^13;

end


loglog(Z, Y_Ps)
axis( [0.01 100 0.01 1])

% loglog(Z, Y_Ps)
% axis( [0.01 100 0.001 100000])
% grid on

Answer 1

[Rik]

You're plotting a single value, but you left the default for plot, which is to only show lines, not markers. So your plot looks like it has no effect.

Co = 2.666;
C1 = - 2.769; 
C2 = - 0.06247;
C3 = 2.676;
C4 = 0.06411;
C5 = - 4.994;
C6 = 0.181;
C7 = 5.374;
C8 = - 0.4159;
C9 = - 2.715;
C10 = - 0.05814;
C11 = 0.6429;
C12 = 0.208;
C13 = - 0.1394;

Ps_ko = - 0.1239;
Ps_k1 = 0.8705;
Z = 0.0553: 0.01: 40;
U_Ps = Ps_ko + Ps_k1*(log10(Z));
Y_Ps = Co + C1*U_Ps + ...
    C2*U_Ps.^2 + C3*U_Ps.^3 + C4*U_Ps.^4 + ...
    C5*U_Ps.^5 + C6*U_Ps.^6 + C7*U_Ps.^7 + ...
    C8*U_Ps.^8 + C9*U_Ps.^9 + C10*U_Ps.^10 + ...
    C11*U_Ps.^11 + C12*U_Ps.^12 + C13*U_Ps.^13;

loglog(Z, Y_Ps)
axis( [0.01 100 0.001 100000])
grid on

You should consider putting all those C values in an array, so you can more easily add or remove values.