for idx = 1 hold on plot(idx,d​ensity(idx​),"*") hold off pause(0.2) end showing incorrect

Name your loop counter idx. For the first execution of the loop, idx should have a value of 1, and it should increase by 1 each consecutive iteration.

Answer 1

[KSSV]

density = density(:) ;
idx = (1:length(density))' ;
figure
plot(idx,density)
comet(idx,density)

Answer 2

[Walter Roberson]

for idx = 1:MaximumNumberOfIterationsGoesHere

Answer 3

[Yogesh]

density = density(:) ;
idx = (1:length(density))' ;
figure
plot(idx,density)
comet(idx,density

[Walter Roberson]

@Yogesh What difference is there between this answer and the one @KSSV posted nearly three years ago, https://www.mathworks.com/matlabcentral/answers/1754580-for-idx-1-hold-on-plot-idx-density-idx-hold-off-pause-0-2-end-showing-incorrect#answer_1001425