I want to create a curve on the histogram?

Hi Guys, first of all I am beginner in Matlab, I did histogram to the data, now I want to create curve on the histogram which I made.

Thank you

Reyadh

[Image Analyst]

What do you mean? Do you mean like you have a bar chart of the counts and you'd like to superimpose a smooth line/curve plot (like a Gaussian or something) on top of the bar chart?

Answer 1

[Thorsten]

If you want to plot something on top of your histogram, use

hold on
plot(your arguments here)

If you want to plot the histogram as a curve, use

H = hist(whatever);
plot(H)

[reyadh Albarakat]

thanks for your answer but it doesn't work with the code. my code is:

if true
  % cd D:\Script\Alhuwaizah_Marsh\Alhuwaizah_1986
H= May_1986(:);
hist(H);
axis([0.0 0.5 0 70])
%hold on
% plot(H)
title('AVHRR NDVI, May 1986, Al-Huwaizah','fontsize',17,'fontweight','bold','fontname','Times New Roman'); 
xlabel('NDVI','fontsize',14)
ylabel('AVHRR Pixels','fontsize',14) 
set(gca,'XMinorTick','on')
set(gca,'YMinorTick','on')
set(gca,'XGrid','on')
set(gca,'YGrid','on')
set(gca,'GridLineStyle',':','linewidth',1)
set(gca,'TickDir','out')
set(gca,'TickLength',[.015 .025])
save('May_Hist_1986.fig'); 
end

[Thorsten]

So exactly what do you want to do, and what doesn't work?

Plot histogram

hist(H)

Plot curve on top

   hi = hist(H);
   hold on
   plot(hi)

[reyadh Albarakat]

Hi Thorsten, I did what you told me but didn't appear any curve on the histogram. by the way I attached the fig.

if true
  % cd D:\Script\Alhuwaizah_Marsh\Alhuwaizah_1986
H= Oct_1986(:);
hist(H);
hi=hist(H);
hold on
plot(hi)
hold off
title('AVHRR NDVI, Oct 1986, Al-Huwaizah','fontsize',17,'fontweight','bold','fontname','Times New Roman'); 
xlabel('NDVI','fontsize',14)
ylabel('AVHRR Pixels','fontsize',14) 
set(gca,'XMinorTick','on')
set(gca,'YMinorTick','on')
set(gca,'XGrid','on')
set(gca,'YGrid','on')
set(gca,'GridLineStyle',':','linewidth',1)
set(gca,'TickDir','out')
set(gca,'TickLength',[.015 .025])
axis([0.0 0.5 0 70])
save('Oct_Hist_1986.fig');
end

[Thorsten]

Try

 [hi cx] = hist(H);
 plot(cx, hi, 'r', 'LineWidth', 10)

What are the following commands showing you?

 subplot(1,2,1), hist(H)
 subplot(1,2,2), plot(cx, hi)

[reyadh Albarakat]

Thank you so much Thorsten, I appreciate you efforts.

Reyadh