Thread Subject: how to check if a parameter is already in workspace

hello

for my m-script i need to check if a parameter is already in workspace.
there was something like isvar(parameter) or like that which gives boolean 1 for yes and 0 for no..
thanks for any help
serkan ozturk

Use exist().

Hi
how can i use "exist" in the M-Function of my GUI

        case 'PB_STARTSIM'
            Check = evalin('base',(char(exist('Uk','var'))));
            if Check == 1;
                open model;
                evalin('base','sim model');
            else
                errordlg('Please load the parameters at first','Error');
            end

I have in the GUI a start simulation button. Before starting the simulation though i need to check if Uk is already in Workspace. If so 'model.mdl' will be opened and simulation will be started. But it doesnt work somehow.
if you can help i would very appreciate
greetings
serkan ozturk

"Serkan " <serkanvai@gmail.com> wrote in message <h2dip9$hh5$1@fred.mathworks.com>...
> Hi
> how can i use "exist" in the M-Function of my GUI
>
> case 'PB_STARTSIM'
> Check = evalin('base',(char(exist('Uk','var'))));

should read

     res=evalin('base','exist(''Uk'',''var'');');

us

"Serkan " <serkanvai@gmail.com> wrote in message <h2dip9$hh5$1@fred.mathworks.com>...
> Hi
> how can i use "exist" in the M-Function of my GUI
>
> case 'PB_STARTSIM'
> Check = evalin('base',(char(exist('Uk','var'))));
> if Check == 1;
> open model;
> evalin('base','sim model');
> else
> errordlg('Please load the parameters at first','Error');
> end
>
> I have in the GUI a start simulation button. Before starting the simulation though i need to check if Uk is already in Workspace. If so 'model.mdl' will be opened and simulation will be started. But it doesnt work somehow.
> if you can help i would very appreciate
> greetings
> serkan ozturk

if exist('n','var')
    (do stuff)
else
~
end

Wouldn't it be easier, safer, and more in keeping with standard practice to have the user either:

1. pass Uk as the GUI is started.
2. Have the button open a load dialog box for the user to specify which parameter file(s) to use.


Just a thought.

Hi
I have two S-Function blocks(S1 and S2) which accepts one parameter each.
How to check whether S1 and S2 both contains same parameter value?
(I mean, if S1 has parameter value "1", I need to restrct S2 parameter value taking "1")