Thread Subject: change color when hold on

Hi,
I have two questions about plots.

I have two matrix X,Y of the same size.

i need to plot curves from them and I use the following code:

plot(X(1,:),Y(1,:))
hold on

for i=2:10
plot(X(i,:),Y(i,:));
end

The problem is that all the curves have the same color,
How can I make it change???

(note: X(1,:) is different from X(i,:) that's why I don't
create a vector x and plot with plot(x,Y))

I also have a problem with plot handles,
if I make
h=plot(x,y)
plot(h,a,b)

I get the error: ??? Error using ==> plot
Data must be a single matrix Y or a list of pairs X,Y

Can anybody help me?
Thank you in advance, -Luca-

Hi,

try this :

figure
hold on

col=hsv(10);
for i=1:10
    plot(X(i,:),Y(i,:),'color',col(i,:));
end

Jérôme

"Luca Cerone" <cerone@to-see.it> wrote in message
<fi9i8n$65v$1@fred.mathworks.com>...
> Hi,
> I have two questions about plots.
>
> I have two matrix X,Y of the same size.
>
> i need to plot curves from them and I use the following code:
>
> plot(X(1,:),Y(1,:))
> hold on
>
> for i=2:10
> plot(X(i,:),Y(i,:));
> end
>
> The problem is that all the curves have the same color,
> How can I make it change???
>
> (note: X(1,:) is different from X(i,:) that's why I don't
> create a vector x and plot with plot(x,Y))
>
> I also have a problem with plot handles,
> if I make
> h=plot(x,y)
> plot(h,a,b)
>
> I get the error: ??? Error using ==> plot
> Data must be a single matrix Y or a list of pairs X,Y
>
> Can anybody help me?
> Thank you in advance, -Luca-

Don't confuse axis handle and curve-handle. plot requires
(optionally) first argument is axis handle.

If you want MATLAB to select automatically colors for you
(very limited number), You can plot all of them together.

h = Plot(X', Y'); % Since each data are a row of X, Y

If you want set color manually

h = Plot(X(1,:),Y(1,:),'r', X(2,:),Y(2,:), 'b', ...);

h is an array of handle h(1) is curve #1, h(2) is curve #2, ...

Next, you can change the color by

set(h(1), 'Color', 'r'); % using color code character
set(h(2), 'Color', [0 0.1 0.1]); % or using 3x1 RGB color
...

Bruno

Thank to both of you,
sorry for the late answer but it's been a very busy period!

Both of your answer have been useful and clarifying!!
Thanks a lot again!

"Bruno Luong" <brunoluong@yahoo.com> wrote in message
<fi9r29$f2p$1@fred.mathworks.com>...
> "Luca Cerone" <cerone@to-see.it> wrote in message
> <fi9i8n$65v$1@fred.mathworks.com>...
> > Hi,
> > I have two questions about plots.
> >
> > I have two matrix X,Y of the same size.
> >
> > i need to plot curves from them and I use the following
code:
> >
> > plot(X(1,:),Y(1,:))
> > hold on
> >
> > for i=2:10
> > plot(X(i,:),Y(i,:));
> > end
> >
> > The problem is that all the curves have the same color,
> > How can I make it change???
> >
> > (note: X(1,:) is different from X(i,:) that's why I don't
> > create a vector x and plot with plot(x,Y))
> >
> > I also have a problem with plot handles,
> > if I make
> > h=plot(x,y)
> > plot(h,a,b)
> >
> > I get the error: ??? Error using ==> plot
> > Data must be a single matrix Y or a list of pairs X,Y
> >
> > Can anybody help me?
> > Thank you in advance, -Luca-
>
> Don't confuse axis handle and curve-handle. plot requires
> (optionally) first argument is axis handle.
>
> If you want MATLAB to select automatically colors for you
> (very limited number), You can plot all of them together.
>
> h = Plot(X', Y'); % Since each data are a row of X, Y
>
> If you want set color manually
>
> h = Plot(X(1,:),Y(1,:),'r', X(2,:),Y(2,:), 'b', ...);
>
> h is an array of handle h(1) is curve #1, h(2) is curve
#2, ...
>
> Next, you can change the color by
>
> set(h(1), 'Color', 'r'); % using color code character
> set(h(2), 'Color', [0 0.1 0.1]); % or using 3x1 RGB color
> ...
>
> Bruno
>
>
>
>
>

Thank to both of you,
sorry for the late answer but it's been a very busy period!

Both of your answer have been useful and clarifying!!
Thanks a lot again!

"Bruno Luong" <brunoluong@yahoo.com> wrote in message
<fi9r29$f2p$1@fred.mathworks.com>...
> "Luca Cerone" <cerone@to-see.it> wrote in message
> <fi9i8n$65v$1@fred.mathworks.com>...
> > Hi,
> > I have two questions about plots.
> >
> > I have two matrix X,Y of the same size.
> >
> > i need to plot curves from them and I use the following
code:
> >
> > plot(X(1,:),Y(1,:))
> > hold on
> >
> > for i=2:10
> > plot(X(i,:),Y(i,:));
> > end
> >
> > The problem is that all the curves have the same color,
> > How can I make it change???
> >
> > (note: X(1,:) is different from X(i,:) that's why I don't
> > create a vector x and plot with plot(x,Y))
> >
> > I also have a problem with plot handles,
> > if I make
> > h=plot(x,y)
> > plot(h,a,b)
> >
> > I get the error: ??? Error using ==> plot
> > Data must be a single matrix Y or a list of pairs X,Y
> >
> > Can anybody help me?
> > Thank you in advance, -Luca-
>
> Don't confuse axis handle and curve-handle. plot requires
> (optionally) first argument is axis handle.
>
> If you want MATLAB to select automatically colors for you
> (very limited number), You can plot all of them together.
>
> h = Plot(X', Y'); % Since each data are a row of X, Y
>
> If you want set color manually
>
> h = Plot(X(1,:),Y(1,:),'r', X(2,:),Y(2,:), 'b', ...);
>
> h is an array of handle h(1) is curve #1, h(2) is curve
#2, ...
>
> Next, you can change the color by
>
> set(h(1), 'Color', 'r'); % using color code character
> set(h(2), 'Color', [0 0.1 0.1]); % or using 3x1 RGB color
> ...
>
> Bruno
>
>
>
>
>