histogram plotting issue

can someone please help me figure out a issue im having plotting the results of a simulation i ran. what im trying to do is use a histogram to plot my data but when i try that i get no results on screen and the axis are all wrong however when i use use plot i get the points on screen altough barely visible without a line connecting them can someone please tell me how to fix my histogram problem or tell me how to get a line to fit my data points when i use plot

here's a plot and hist version of my code

%plot version 
win=0
step=0
for p=.1:.1:.9

for i=1:1:100

     a=3
     b=3
     c=3

           while a>0 && b>0 && c>0

             step=step+1

        d=rand(1,3)

        if d(1,1)<p && d(1,2)<p && d(1,3) <p
            a=a+0
            b=b+0
            c=c+0

        elseif d(1,1)>p && d(1,2) >p &&d(1,3) >p
            a=a+0
            b=b+0
            c=c+0

        elseif d(1,1)<p && d(1,3) < p

            a= a -1
            b= b+2
            c= c-1

        elseif d(1,1)>p &&d(1,3) >p
          a= a -1
            b= b+2
            c= c-1

        elseif d(1,3)<p &&d(1,2) < p
            a= a +2
            b= b-1
            c= c-1

        elseif d(1,2)>p && d(1,3) >p
          a= a +2
            b= b-1
            c= c-1

        elseif d(1,1)<p &&d(1,2) < p            
            a= a -1
            b= b-1
            c= c+2

        elseif d(1,1)>p && d(1,2) >p
          a= a -1
            b= b-1
            c= c+2

        end
       end
  win=win+1
  end
  %axis([0 5 0 75 ])
  avg=step/100
  plot(p,avg)
  hold on 
  end
  disp avg 

%histogram version
win=0
step=0
for p=.1:.1:.9

for i=1:1:100

     a=3
     b=3
     c=3

           while a>0 && b>0 && c>0

             step=step+1

        d=rand(1,3)

        if d(1,1)<p && d(1,2)<p && d(1,3) <p
            a=a+0
            b=b+0
            c=c+0

        elseif d(1,1)>p && d(1,2) >p &&d(1,3) >p
            a=a+0
            b=b+0
            c=c+0

        elseif d(1,1)<p && d(1,3) < p

            a= a -1
            b= b+2
            c= c-1

        elseif d(1,1)>p &&d(1,3) >p
          a= a -1
            b= b+2
            c= c-1

        elseif d(1,3)<p &&d(1,2) < p
            a= a +2
            b= b-1
            c= c-1

        elseif d(1,2)>p && d(1,3) >p
          a= a +2
            b= b-1
            c= c-1

        elseif d(1,1)<p &&d(1,2) < p            
            a= a -1
            b= b-1
            c= c+2

        elseif d(1,1)>p && d(1,2) >p
          a= a -1
            b= b-1
            c= c+2

        end
       end
  win=win+1
  end
  %axis([0 5 0 75 ])
  avg=step/100
  hist(avg,p)
  hold on 
  end
  disp avg

Answer 1

[Fangjun Jiang]

You need to learn to use vector or matrix, the essence of MATLAB.

Pre-allocate you p as p=.1:.1:.9; p will be a 1x9 vector, you can reference individual element as p(1), p(2), etc.

Pre-allocate avg=zeros(size(p)), avg will be a all-zero vector the same size as p. Go through your loop, calculate the value of avg that is corresponding to p.

Then you can use plot(p,avg). It will plot a curve.

Right now, you are plotting one dot at a time. Since you have the hold on, it shows all the dots.

Add a semi-colon ";" at the end of each line, it will prevent the echo in the MATLAB Command Window, which slows down the program quite a lot.