plots:-contourplot(16.70196911*2^(1/2)*((x^2 + 0.1*y)/((1 - x)*(3*x^2 + 0.2*y)))^(1/2)/(4.373839156*(x^2 + 0.1*y)/((1 - x)*(3*x^2 + 0.2*y)) + 1)^(1/2), x = 0.001 .. 1, y = 0.001 .. 1, contours = 20, thickness = 0, coloring = ["blue", "yellow"], axes = "boxed", filledregions = true)

I have tried many times, such as adding legendstyle = [position=correct],legend = true command, but it always report errors.

Can anyone help me solve this problem? Thank you.

P__eff := (4.881726014*10^(-13)*(x__1^2 + 0.3)*R/((1 - x__1)*(3*x__1^2 + 0.6)*(7.654218526*10^(-21)*R^2*(x__1^2 + 0.3)/((1 - x__1)*(3*x__1^2 + 0.6)) + 1)))*1000;
expr := eval(P__eff(R));
plot([seq(expr, x__1 = [0.3, 0.5, 0.7])], R = 10000000 .. 10000000000000, legend = [seq('x__1' = x__1, x__1 = [0.3, 0.5, 0.7])], color = ["blue", "red", "gold"], thickness = 3, axes = "boxed", gridlines = true, labels = [R, P__eff], axis[1] = [mode = log]);

Obviously, there is a problem with the logarithmic function curve in the interval of 10^7 to10^10. Can anyone tell me how to solve it？thank you very much！