Re: Write output to file continuously
- To: mathgroup at smc.vnet.net
- Subject: [mg31114] Re: [mg31074] Write output to file continuously
- From: Omega Consulting <omega_consulting at yahoo.com>
- Date: Wed, 10 Oct 2001 19:14:33 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
At 02:33 AM 10/6/2001, bradamanteus at yahoo.com wrote:
>1.Here the NestList works but the output is not written to a file. Although
>it does create a file called datafilename with a content of NULL
>
>
>
>Clear[outputstep];
>outputstep[datafilename_String][{variablelist_}] :=
> nextstate[{variablelist}] >>> datafilename
>
>Clear[simulation];
>simulation[datafilename_String, simlength_][{variablelist_}] :=
> NestList[outputstep[datafilename], {variablelist}, simlength]
>
>simulation["dat3", 3][{initiallist}]
There are two problems here. Look at the definition of outputstep.
?outputstep
Global`outputstep
outputstep[datafilename_String][{variablelist_}] :=
nextstate[{variablelist}]
The above definition is interpreted as the expression to be Put. The second
problem is that this form of Put interprets datafilename as the actual file
name, not a variable.
!!datafilename
Null
>2. This creates a filename named dat3, but only has the initial list of
>variables and NestList cannot be calculated.
>
>
>
>Clear[outputstep];
>outputstep[datafilename_String][{variablelist_}] :=
> PutAppend[nextstate[{variablelist}], datafilename]
>
>Clear[simulation];
>simulation[datafilename_String, simlength_][{variablelist_}] :=
> NestList[outputstep[datafilename], {variablelist}, simlength]
>
>simulation["dat3", 3][{initiallist}]
This fixes the above problems, but another is still there. The output of
outputstep is the input for the next nesting, but the output of
PutAppend[x, y] is Null, not x. Instead, outputstep should be
outputstep[datafilename_String][{variablelist_}] :=
Module[{new = nextstate[{variablelist}]},
PutAppend[new, datafilename];
new
]
>I would appreciate any assistance.
>
>Amateur mathematica programmer
>Leanne Ussher
>bradamanteus at yahoo.com
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