I'm trying to combine the plot of a function with a vector plot, but no matter what option I choose for VectorPoints, the resulting combined plot just looks ridiculous. For example, the combined plot with the "VectorPoints -> Coarse" option looks like this:
What I actually want is just one vector plot line with small arrows that sits slightly above the solid red line of the function, and one that sits slightly below it.
Edit 1: this is the combined plot using StreamPlot instead of VectorPlot with the same parameters, i.e.
spfig = StreamPlot[{1, f[x, y]}, {x, 40, 75}, {y, 1, 5}, StreamPoints -> Coarse];
Show[fig1, spfig]
Edit 2: here is a MWE:
F[x_, y_] := 1 - (2 (64 - x)^(1/3) y[x]^2)/(2 (64 - x)^(1/3) + y[x]^3);
Eq = D[y[x], x] == F[x, y]/2 // Simplify;
NDSolveRes = NDSolve[{Eq, y[53.854] == 2.632}, y, {x, 0, 70}];
fig1 = Plot[y[x] /. NDSolveRes, {x, 0, 90}, AxesLabel -> {"x", "y"}, PlotStyle -> {Darker[Red], Thickness -> 0.003}];
f[x_, y_] := 1/2 - (y^2 (64 - x)^(1/3))/(y^3 + 2 (64 - x)^(1/3));
vpfig = VectorPlot[{1, f[x, y]}, {x, 40, 75}, {y, 1, 5}, VectorPoints -> Coarse];
Show[fig1, vpfig]
Edit 3: here are the error messages:
StreamPlot
with theStreamPoints
option. $\endgroup$