how to make automatic graph script with a for loop?

Hi everybody, i'm trying to make the folowing script for grahp 7 points, but i do not understand why only represent only one point of the seven that i should draw.

hold on
grid on
n=0;
k=1;
step=1;

for i=7
    y=con1+step;
    x=1+step;
    plot(x, y, '*');
    k=k+1;
end

This are the 7 points

con1 =4.3e10
con2 =1.16e10
con3 =5.44e9
con4 =3.15e9
con5 =1.98e9
con6 =1.4e9
con7 =1.05e9

Can anyone help me to structure it better the code?. Thanks in advance

Answer 1

[KSSV]

con = [4.3e10 ; 1.16e10;5.44e9;3.15e9;1.98e9;1.4e9;1.05e9 ] ;

hold on
grid on
n=0;
k=1;
step=1;
for i=1:7
    y=con(i)+step;
    x=1+step;
    plot(x, y, '*');
    k=k+1;
end

[Tony Castillo]

Thanks for your help, in the code just lack x="(i)"+step; instead that x=1+step.

hold on grid on n=0; k=1; step=1; for i=1:7 y=con(i)+step; x=1+step; plot(x, y, '*'); k=k+1; end

Answer 2

[KSSV]

Use hold on after plot command inside the loop...using hold on points are plotted on the same figure. If not every time new figure opens.

[Tony Castillo]

Using the hold on function as you recommend me, i have the same results than before.

n=0;
k=1;
step=1;

for i=7
    y=con1+step;
    x=1+step;
    plot(x, y, '*');
    k=k+1;
    hold on
    grid on
end

[Guillaume]

The hold command needs to be issued before plotting.

Of course, you also have the issue highlighted by Adam

[Adam]

As long as the hold is before the 2nd plot it should work fine I would think. Of course ideally you would give the axes handle to the hold command

hold( hAxes, 'on' )

to avoid any unpleasant bugs creeping in, but in a simple script just

hold on

tends to work fine.

Answer 3

[Adam]

Your for loop doesn't change anything so you just plot the same point every time. Neither con1 nor step changes so neither do x or y.

Did you mean to update step using 'i' or something like that? Or do you want con1 upto con7? In which case store them in a single array instead and access as

con(i)

rather than

con1

[Tony Castillo]

When i do it, appear this error. Undefined function or variable 'con'.

Error in UntitledFOR (line 6) y=con(i)+step;

This is the code with your recommendation.

[Adam]

Well, of course you have to define con as an array containing all your values instead of the 7 variables you currently have as con1 to con7.