my gif constructor code is too slow matplotlib

Question

I am doing my final thesis and I need to create some gifs for a lot of different systems, the problem is that my code is REALLY slow and I need a way to increase the speed, I'm using imageio to do it

    fig,ax=plt.subplots()
plt.title("Variacion diaria")
plt.xlim(0,max(dia)+1)
plt.ylim(0,max(nstot)+1)
filenames=[]

plt.plot(nstot[:1],'b',label=("Susceptibles totales"))
plt.plot(nitot[:1],'r',label=("Infectados totales"))
plt.plot(nrtot[:1],'g',label=("Recuperados totales"))
plt.plot(ndtot[:1],'k',label=("Muertos totales"))
plt.legend()
for i in range(0,diax):
    plt.plot(nstot[:i],'b')
    plt.plot(nitot[:i],'r')
    plt.plot(nrtot[:i],'g')
    plt.plot(ndtot[:i],'k')
    #Create frame and saving it
    filename=f'{i}.png'
    filenames.append(filename)
    #save frame
    plt.savefig(filename)
    plt.close

#gif construction
with imageio.get_writer("gifprueba.gif" , mode='?') as writer:
    for filename in filenames:
        image=imageio.imread(filename)
        writer.append_data(image)
#Delete frames 
for filename in set(filenames):
    os.remove(filename)

Is there any way, library or method to make it faster?