how do i plot a straight line and also change then range of the x axis and y axis ?

Vonew=45;
Vonew2=15

Vonew2 = 15

vin=30;
y=Vonew; %i get my Voutnew=45
x=Vonew2;
plot( Vonew,y, 'o', 'LineWidth', 2);
hold on
plot( Vonew2,x, 'o', 'LineWidth', 2);
xlabel('vin', 'FontSize', 20);
ylabel('vo', 'FontSize', 20);
title('vo vs vin', 'FontSize', 20);

Answer 1

[Rik]

I suspect you want something like xline or yline:

Vonew=45;
Vonew2=15

Vonew2 = 15

vin=30;
y=Vonew; %i get my Voutnew=45
x=Vonew2;
plot( Vonew,y, 'o', 'LineWidth', 2);
hold on
plot( Vonew2,x, 'o', 'LineWidth', 2);
xlabel('vin', 'FontSize', 20);
ylabel('vo', 'FontSize', 20);
title('vo vs vin', 'FontSize', 20);

xline(30),yline(20)
axis([14 46 14 46])

Answer 2

[Mathieu NOE]

hello Grace

maybe this ?

I added a line between the two points you defined and using xlim and ylim you can change the visual appearance of your graph

Vonew=45;
Vonew2=15;
vin=30;
y=Vonew; %i get my Voutnew=45
x=Vonew2;

% line 
n = 100; % dots 
x_line = linspace(Vonew,Vonew2,n); % put here the first and last point x coordinates
y_line = linspace(y,x,n); % put here the first and last point y coordinates

plot( Vonew,y, 'o', 'LineWidth', 2);
hold on
plot( Vonew2,x, 'o', 'LineWidth', 2);
plot( x_line,y_line, 'k--', 'LineWidth', 2); % line
% set x and y display limits
xlim([0 1.4*max(x_line)]);
ylim([0 1.4*max(y_line)]);

xlabel('vin', 'FontSize', 20);
ylabel('vo', 'FontSize', 20);
title('vo vs vin', 'FontSize', 20);
hold off

[Rik]

You don't even need the linspace:

Vonew=45;
Vonew2=15;
vin=30;
y=Vonew; %i get my Voutnew=45
x=Vonew2;

% line 
n = 100; % dots 
x_line = [Vonew,Vonew2]; % put here the first and last point x coordinates
y_line = [y,x]; % put here the first and last point y coordinates

plot( Vonew,y, 'o', 'LineWidth', 2);
hold on
plot( Vonew2,x, 'o', 'LineWidth', 2);
plot( x_line,y_line, 'k--', 'LineWidth', 2); % line
% set x and y display limits
xlim([0 1.4*max(x_line)]);
ylim([0 1.4*max(y_line)]);

xlabel('vin', 'FontSize', 20);
ylabel('vo', 'FontSize', 20);
title('vo vs vin', 'FontSize', 20);
hold off

[Mathieu NOE]

hello @Rik

you're right - it's even better this way

I'm sometimes still coding like I was doing 20 years ago