Number and alphabet

Hi,

I have edittext and pushbutton.

If I write with "sym(' ')" for example a1 or R2 or alfa34...matlab works good. If I write any text in this format a1 into edittext, then I want to enable pushbutton.

But if the firts is number for example 1a or 45R or 89gama, then matlab generate error. So if I write any text in this format 2a into edittext, then I want to disable pushbutton.

Please, how Can I do this?

Thank you

[Oleg Komarov]

You cannot create variables which start from a number. This is a naming convention for variables and functions.

[john]

Yes, I understand...but I need avoid, that somebody will insert variables which start from a number.

[John D'Errico]

Use a regular expression to test for this event.

Answer 1

[Titus Edelhofer]

Hi,

you can use isvarname for this purpose, something like

str = get(handles.edit1, 'string');
if isvarname(str))
  set(handles.pushbutton1, 'enable', 'on')
else
  set(handles.pushbutton1, 'enable', 'off')
end

Titus

[john]

and also I need...If I write only number or a1 or R55, then enable pushbutton.

It is possible?

[Oleg Komarov]

isvarname does that, try Titus' solution.

[john]

Sorry guys,

but if I write number for example 53, pushbutton is not enabled....I think it is not working..

[john]

where can be a problem? :(

[Titus Edelhofer]

Hi,

do I understand right: "only a number" should enable as well, although it's not a variable name? Then change the if to

if isvarname(str) || ~isnan(str2double(str))

Titus

[Walter Roberson]

Should only non-negative integers be allowed like 53, or should negatives be allowed? Floating point numbers? Exponential format? Titus's use of str2double() will allow numbers in all formats, including -3.83456e-009

[john]

Titus, yes only number or string in form "R43" or "beta9".

Walter, only positive floating point numbers without zero....maybe it can be used

if any(regexp(char(get(handles.edit1,'String')),'[^1-9.]'))

set(handles.pushbutton1,'enable','off');

else

set(handles.pushbutton1,'enable','on');

[john]

I think, that command "~isvarname(string) || isnan(str2double(string))" doesn't work. Do you have any Idea?

,

,

if ~isvarname(string) || isnan(str2double(string))

set(handles.pushbutton1,'enable','off');

else

set(handles.pushbutton1,'enable','on');

end;

[Walter Roberson]

What difficulties are you encountering?