# Plot of integral curves not showing all of them

Dear all,

I have tried to solve this initial value problem

ty' + 2y = 4t^{2}

y(1) = 2

I plot it with this code:

using Plots, LaTeXStrings, Plots.PlotMeasures
gr()

f(x) = x^(2) + (1 / x^(2))

p = plot(f, -1, 5, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label=L"t^{2} + \frac{c}{t^{2}}", framestyle=:zerolines,
legend=:outerright)

for i = 1:0.5:3
g(x) =  x^(2) + (i / x^(2))
plot!(p, g, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label="", framestyle=:zerolines,
legend=:outerright)
end

for i = 1:0.5:3
g(x) =  x^(2) - (1 / x^(2))
plot!(p, g, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label="", framestyle=:zerolines,
legend=:outerright)
end

display(p)



My plot is missing a lot of curvesâ€¦

The book can plot it nicely:

I wonder how to plot like the book with Julia. Thanks

Here is what I get:

I did a minor change of your code, but I donâ€™t think that is the reason for the difference:

f(x) = x^2 + 1/x^2

p = plot(f, -2,2, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label=L"t^{2} + \frac{c}{t^{2}}", framestyle=:zerolines,
legend=:outerright)

for i = 1:0.5:3
g(x) =  x^(2) + (i / x^(2))
plot!(g, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label="", framestyle=:zerolines,
legend=:outerright)
end

for i = 1:0.5:3
g(x) =  x^(2) - (1 / x^(2))
plot!(g, xticks=false, xlims=(-2, 2), ylims=(-2, 4),
bottom_margin=10mm, label="", framestyle=:zerolines,
legend=:outerright)
end

plot!()


I used the â€śjupyterâ€ť plug-in to VSCode.

1 Like

I still get half curves instead of one like yours, I think the problem is the JupyterLab I am using, or I am still using Julia 1.7.3

I try on REPL to plot and I get better result:

Merci beaucoup!!!