MATLAB Central Newsreader - Handle 2 axes at a time...

Handle 2 axes at a time...

JDK_3 — Fri, 28 Aug 2009 19:03:59 -0400

Hi guys,
I am trying to make a GUI in MATLAB that plots two graphs(say a sine
wave and 2nd is its shifted version).
But I am unable to plot them differently on two different axes.

Here is the piece of code:

S.ax1 = axes('xlim',[0 1],'ylim',[0 1]);
%define axes1
set(S.ax1,'unit','pix','position',[50 325 570 250]);

S.ax2 = axes('xlim',[0 1],'ylim',[0 1]);
%define axes2
set(S.ax2,'unit','pix','position',[50 60 570 250]);

function [] = push_call(varargin)

S = varargin{3};
P = get(S.pop,'val'); %get value of popup menu 'pop'

switch P
    case 1
       axes(S.ax1);
                x = -5:0.01:5;
                y = sin(x);
                plot(x,y);

        switch findobj(get
(S.select_option,'selectedobject')) %get selected
radio button
            case S.advance
                axes(S.ax2);
                x = -5:0.01:5;
                y = sin(x+2);
                plot(x,y);
        end
end

I am getting an error

>Reference to non-existent field 'ax1'.
>Error in ==> plot_1>push_call at 67 axes(S.ax1);

please help me, or say where i am wrong.
thanks in advance

Re: Handle 2 axes at a time...

matt dash — Fri, 28 Aug 2009 20:17:19 -0400

JDK_3 <jaydu1904@gmail.com> wrote in message <0bafa2ba-ed9b-4487-a6a2-a1aaa64b54da@d15g2000prc.googlegroups.com>...
> Hi guys,
> I am trying to make a GUI in MATLAB that plots two graphs(say a sine
> wave and 2nd is its shifted version).
> But I am unable to plot them differently on two different axes.
>
> Here is the piece of code:
>
> S.ax1 = axes('xlim',[0 1],'ylim',[0 1]);
> %define axes1
> set(S.ax1,'unit','pix','position',[50 325 570 250]);
>
> S.ax2 = axes('xlim',[0 1],'ylim',[0 1]);
> %define axes2
> set(S.ax2,'unit','pix','position',[50 60 570 250]);
>
>
> function [] = push_call(varargin)
>
> S = varargin{3};
> P = get(S.pop,'val'); %get value of popup menu 'pop'
>
> switch P
> case 1
> axes(S.ax1);
> x = -5:0.01:5;
> y = sin(x);
> plot(x,y);
>
> switch findobj(get
> (S.select_option,'selectedobject')) %get selected
> radio button
> case S.advance
> axes(S.ax2);
> x = -5:0.01:5;
> y = sin(x+2);
> plot(x,y);
> end
> end
>
>
>
> I am getting an error
>
> >Reference to non-existent field 'ax1'.
> >Error in ==> plot_1>push_call at 67 axes(S.ax1);
>
>

After defining S.ax1 and S.ax2 in your initial code, do you call guidata to store these values? You need to do that. Something like guidata(gcf,S).

Re: Handle 2 axes at a time...

Matt Fig — Fri, 28 Aug 2009 20:26:03 -0400

I would be willing to bet that you set the callback to the pushbutton before S.ax1 was created. When you are programming by storing all info in a structure S, you need to assign callbacks that take S as an argument AFTER all needed fields of S have been set. See the added line below.

S.ax1 = axes('xlim',[0 1],'ylim',[0 1]);
%define axes1
set(S.ax1,'unit','pix','position',[50 325 570 250]);

S.ax2 = axes('xlim',[0 1],'ylim',[0 1]);
%define axes2
set(S.ax2,'unit','pix','position',[50 60 570 250]);

set(push,'callback',{@push_call,S}) % ADDED AFTER S.ax1, S.ax2 are created!!!!

function [] = push_call(varargin)

S = varargin{3};
P = get(S.pop,'val'); %get value of popup menu 'pop'

switch P
    case 1
       axes(S.ax1);
                x = -5:0.01:5;
                y = sin(x);
                plot(x,y);

        switch findobj(get
(S.select_option,'selectedobject')) %get selected
radio button
            case S.advance
                axes(S.ax2);
                x = -5:0.01:5;
                y = sin(x+2);
                plot(x,y);
        end
end