[scilab-Users] predefined functions in Scilab

[Mathieu Dubois]

Le 24/09/2011 13:18, Manjusha Joshi a écrit :
>
>
> On Fri, Sep 23, 2011 at 2:23 PM, Mathieu Dubois <mathieu.dubois at limsi.fr
> <mailto:mathieu.dubois at limsi.fr>> wrote:
>
>     __
>     On 09/23/2011 10:32 AM, Manjusha Joshi wrote:
>>     Thanks Mathieu, for pointing out  the difference.
>>
>>     Please go through the mail for in line reply.
>>
>>     On Fri, Sep 23, 2011 at 1:25 PM, Mathieu Dubois
>>     <mathieu.dubois at limsi.fr <mailto:mathieu.dubois at limsi.fr>> wrote:
>>
>>
>>
>>         Le 23/09/2011 02:54, Manjusha Joshi a écrit :
>>
>>             Hello
>>
>>
>>                For your problem you should have a look at the funcprot
>>             function.
>>
>>                However, the default mode is to issue a warning when
>>             redefining
>>                predefined functions.
>>
>>             Thanks for reply.
>>
>>             I tried following
>>              A  =
>>
>>                 2.    3.    4.    78.
>>
>>
>>             -->funcprot(2)
>>
>>
>>             -->sum(A)
>>              ans  =
>>
>>                 87.
>>
>>             -->sum=98
>>                   !--error 223
>>             It is not possible to redefine the sum primitive this way
>>             (see clearfun).
>>
>>
>>             -->deff('y=f(x)','y=x*x')
>>
>>             -->deff('y=f(x)','y=2*x*x')
>>                                      !--error 111
>>             Trying to re-define function f.
>>
>>
>>             User defined function should be redefined. At the same
>>             time scilab
>>             predefined functions should not.
>>             I tried following:
>>
>>             -->clearfun f
>>              ans  =
>>
>>               F
>>
>>             -->clearfun sum
>>              ans  =
>>
>>               T
>>             Now it is allowing to redefine sum which should be
>>             protected. On the
>>             other hand it is not allowing to redefine the function f.
>>             Which one
>>             needs to redefine several times in one session.
>>
>>         clearfun is to clear predefined functions like sum (maybe it
>>         should be called clearpredef).
>>
>>         To redefine your function f, use clear f.
>>         You can check that f exists with the exists function (not
>>         mandatory).
>>
>>      True! Variables and user defined function can be cleared by clear
>>     command.
>>
>>
>>     -->exists('f')
>>      ans  =
>>
>>         1.
>>     works fine with user defined functions. How ever, which are
>>     already known to user since, it is defined by user.
>>     How ever, Scilab defined functions, which I will call as
>>     predefined functions are not all known to user, so there is risk
>>     of pre defined function
>>     get assigned by user by mistake.
>>
>>
>>     -->exists('prod')
>>      ans  =
>>
>>         0.
>>
>>     Is there any way to check that (for example)  prod is a predefined
>>     function?
>     I'm not sure to understand: if you use funcprot(2) all functions are
>     protected so there is no assignement by mistake. Then you can define
>     your function f and clear it when needed...
>
>
> Yup! This will work.
OK.
> I think funcprot(2) should be default mode.
Hum, you can always add this in your startup file or in the systme-wide 
startup file (see help("startup")).
> Regards
>
>
>>
>>
>>
>>                On 09/22/2011 12:51 PM, Manjusha Joshi wrote:
>>
>>                    Hello,
>>
>>                    sum, prod etc. are predefined functions in scilab.
>>
>>                    if some one with out knowing the name of the
>>              predefind function
>>                    use  it as avariable name, as follows:
>>
>>
>>                    -->A=[2,3,4,78]
>>                      A  =
>>
>>                        2.    3.    4.    78.
>>
>>                    -->sum(A)
>>                      ans  =
>>
>>                        87.
>>
>>                    -->sum=96
>>                      sum  =
>>
>>                        96.
>>
>>                    -->sum(A)
>>                           !--error 21
>>                    Invalid index.
>>
>>
>>
>>                      scilab not even complains. In old versions at
>>             least there was
>>                    some error message.
>>
>>                    This happens in the current session only.
>>                    Is there any way to protect the predefined
>>             functions and their
>>                    names?
>>                    I think we should declare these function names as
>>             predefined
>>                    functions.
>>
>>
>>
>>
>>
>>
>>
>>
>>             --
>>
>>
>>     -Manjusha
>
>
>
>
> --
> Manjusha S. Joshi
> Mobile:  09822 319328
> blog:http://manjushajoshi.wordpress.com/
>
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