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Re: Export with append??

  • To: mathgroup at smc.vnet.net
  • Subject: [mg129491] Re: Export with append??
  • From: Murray Eisenberg <murray at math.umass.edu>
  • Date: Fri, 18 Jan 2013 00:50:12 -0500 (EST)
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  • References: <kd5hu2$jjp$1@smc.vnet.net> <20130117041653.995FF6882@smc.vnet.net>

But surely appending like that won't work for many export formats. E.g., I hesitate to think what it might do to a PDF export.

On Jan 16, 2013, at 11:16 PM, Szabolcs <szhorvat at gmail.com> wrote:

> Hello Maarten,
>
> In fact there is a simple way to make Export append rather than overwrite.  Please see here:
>
> http://mathematica.stackexchange.com/a/2228/12
>
> You just need to use a stream in place of the file name:
>
> file = OpenAppend["out.txt"]
>
> Export[file, data, "CSV"];
> WriteString[file, "\n"];
>
> Close[file]
>
> On Wednesday, 16 January 2013 01:38:58 UTC-5, Maarten van der Burgt  wrote:
>> Dear Alexei,
>>
>>
>>
>> Thanks for your help. Hope the Wolfram folks are reading this as well.
>>
>> Something simple like this should really be an option in the function
>>
>> Export.
>>
>>
>>
>> Meanwhile I found back something similar for XLS files in my knowledge
>>
>> base:
>>
>>
>>
>> XLAppend[oldfile_, newfile_, newdata_] :=  Module[
>>
>>
>>
>> {sheets, olddata, completedata},
>>
>>
>>
>>  sheets = Import[oldfile, "Sheets"];
>>
>>
>>
>>  olddata = {#, Import[oldfile, {"Sheets", #}]} & /@ sheets;
>>
>>
>>
>>  completedata = Join[olddata, newdata];
>>
>>
>>
>> Export[newfile, Rule @@@ completedata]
>>
>>
>>
>> ]
>>
>>
>>
>>
>>
>>
>>
>> Best regards,
>>
>>
>>
>>
>>
>>
>>
>> Maarten
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Maarten van der Burgt
>>
>>
>>
>> Product Engineering  - ICOS Division
>>
>>
>>
>> ________________________________
>>
>>
>>
>> KLA-Tencor | ICOS Division
>>
>> Tel: +32 16 398220 | Direct: +32 16 398263 | Fax: +32 16 400067
>>
>>
>>
>> KLA-TENCOR (Belgium) - Haasrode Research Park 1112 - Esperantolaan 8 =
-
>>
>> B-3001 Leuven - BELGIUM
>>
>>
>>
>> Mail: maarten.vanderburgt at kla-tencor.com
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> From: Alexei Boulbitch [mailto:Alexei.Boulbitch at iee.lu]
>>
>> Sent: maandag 14 januari 2013 10:22
>>
>> Cc: Maarten van der Burgt
>>
>> Subject: Re: Export with append??
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hallo,
>>
>>
>>
>>
>>
>>
>>
>> With a command like
>>
>>
>>
>>
>>
>>
>>
>> Export["myfile.dat", results, "List" ]
>>
>>
>>
>>
>>
>>
>>
>> is there a way to append the results to an existing myfile.dat, rather
>>
>>
>>
>> than creating or overwriting an existing file?
>>
>>
>>
>>
>>
>>
>>
>> thanks for your help,
>>
>>
>>
>>
>>
>>
>>
>> Maarten
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Hi, Maarten,
>>
>>
>>
>> A simple workaround is to import your file, append a new file to it and
>>
>> then - to export the combined list. Assume that your mathematica
>>
>> notebook entitled "trialImportExport.nb"  is situated in the same folder
>>
>> as the already existing list entitled "myfile.dat".
>>
>>
>>
>> To be precise I generated the file myfile.dat with the list:
>>
>>
>>
>> {25, 36, 49}
>>
>>
>>
>> in it. Assume further that I want to append the list
>>
>>
>>
>> {a,b,c}
>>
>>
>>
>> to it. Then the code
>>
>>
>>
>>
>>
>>
>>
>> lst1=Import[NotebookDirectory[]<>"myfile.dat"]//Flatten;
>>
>>
>>
>> lst2={a,b,c};
>>
>>
>>
>> lst3=Append[lst1,lst2]//Flatten;
>>
>>
>>
>> Export[NotebookDirectory[]<>"myfileNew.dat",lst3]
>>
>>
>>
>>
>>
>>
>>
>> Does the job. The output cell below:
>>
>>
>>
>>
>>
>>
>>
>> D:\Documents and Settings\ABo\My
>>
>> Documents\Works\Mathematica_works\Examples\TrialFiles\myfileNew.dat
>>
>>
>>
>>
>>
>>
>>
>> shows that the file has been successfully exported.
>>
>>
>>
>> I intentionally gave the resulting file a new name, "myfileNew.dat", to
>>
>> check the result, but the old name can also be given to it.
>>
>>
>>
>>
>>
>>
>>
>> Have fun, Alexei
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> Alexei BOULBITCH, Dr., habil.
>>
>>
>>
>> IEE S.A.
>>
>>
>>
>> ZAE Weiergewan,
>>
>>
>>
>> 11, rue Edmond Reuter,
>>
>>
>>
>> L-5326 Contern, LUXEMBOURG
>>
>>
>>
>>
>>
>>
>>
>> Office phone :  +352-2454-2566
>>
>>
>>
>> Office fax:       +352-2454-3566
>>
>>
>>
>> mobile phone:  +49 151 52 40 66 44
>>
>>
>>
>>
>>
>>
>>
>> e-mail: alexei.boulbitch at iee.lu

---
Murray Eisenberg                                    
murray at math.umass.edu
Mathematics & Statistics Dept.      
Lederle Graduate Research Tower            phone 413 549-1020 (H)
University of Massachusetts                               413 5 (W)
710 North Pleasant Street                         fax   413 545-1801
Amherst, MA 01003-9305








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