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MathGroup Archive 1996

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Re: How to plot a date file? Some questions, some solutions.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg4854] Re: How to plot a date file? Some questions, some solutions.
  • From: vvs124 at rsphy1.anu.edu.au (Victoria Steblina)
  • Date: Thu, 26 Sep 1996 22:42:15 -0400
  • Organization: Australian National University
  • Sender: owner-wri-mathgroup at wolfram.com

lbliao <lbliao at alumni.caltech.edu> wrote:

>The following is a file that I want to plot
>as either R versus FQ or DG versus FQ.
>Note it has three columns of numbers preceeded
>by two letter identifiers R_, DG, FQ, where
>R_ is a two letter identifier. _ denotes
>white space.
>
>
>R  999.1E-3,DG 000.0E+0,FQ 1.000E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.023E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.047E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.072E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.096E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.122E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.148E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.175E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.202E+3
>R  999.1E-3,DG 000.0E+0,FQ 1.230E+3
>R  998.9E-3,DG 000.0E+0,FQ 7.244E+3
>R  998.9E-3,DG 000.0E+0,FQ 7.413E+3
>R  999.0E-3,DG 000.0E+0,FQ 7.585E+3
>R  998.9E-3,DG 000.0E+0,FQ 7.762E+3
>R  998.9E-3,DG 000.0E+0,FQ 7.943E+3
>R  998.9E-3,DG 000.0E+0,FQ 8.128E+3
>R  999.0E-3,DG 000.0E+0,FQ 8.317E+3
>R  999.0E-3,DG 000.0E+0,FQ 8.511E+3
>R  999.0E-3,DG 000.0E+0,FQ 8.709E+3
>R  999.0E-3,DG 000.0E+0,FQ 8.912E+3
>R  999.0E-3,DG 000.0E+0,FQ 9.120E+3
>R  999.0E-3,DG 000.0E+0,FQ 9.332E+3
>R  998.8E-3,DG-000.0E+0,FQ 9.999E+3
>R  998.8E-3,DG-000.0E+0,FQ 10.00E+3

--- skip ---
>The first problem is to separate the list into three columns
>a=ReadList["c:\\file", Word, 
>WordSeparators -> {"R", ",DG", ",FQ"}, 
>RecordLists->True]
>
>For RecordList -> True, see page 182, 
>For WordSeparators -> {}, see p 496,
>
>This has one PROBLEM. Although all the three number fields are separated,
>they are not numbers any more, but words.
>
>The second problem is to get any two columns from the three columns so that
>they can be plotted I do not see how to directly get two columns other than
> transposing getting the rows, and then transposing back again, ie
>
>Transpose[Transpose[a][[{1,3}]]]

Try this:

a=ReadList["data", Word, 
WordSeparators -> {"R", ",DG", ",FQ"},
RecordLists->True]//ToString;   (* Make it a string for further
replacements*)

That will convert all "exponential" notations into Mma number format 
(unless I misread something, this is what you want) and then convert
string 
"a" to the list of symbols:

toSymbols = StringReplace[a, {"E" -> " 10^"}] // ToExpression;

Build up lists for R, DG, and FQ respectively:

Rlist  = First /@ toSymbols // Flatten
DGlist = Transpose[{Transpose[toSymbols][[2]]}] // Flatten
FQlist = Last /@ toSymbols // Flatten

(local) Out[79]=
{0.9991, 0.9991, 0.9991, 0.9991, 0.9991, 0.9991, 0.9991, 0.9991,
0.9991, 0.9991, 0.9989, 0.9989, 0.999, 0.9989, 0.9989, 0.9989, 
 
  0.999, 0.999, 0.999, 0.999, 0.999, 0.999, 0.9988, 0.9988}
(local) Out[80]=
{0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0., 0.,
0., 0., 0., 0., 0., 0., 0.}
(local) Out[81]=
{1000., 1023., 1047., 1072., 1096., 1122., 1148., 1175., 1202., 1230.,
7244., 7413., 7585., 7762., 7943., 8128., 8317., 8511., 
 
  8709., 8912., 9120., 9332., 9999., 10000.}

Transpose two lists (will produce 2 tables of values: R vs FQ  and DG
vs FQ)
and ListPlot them:

RvsFQ  = ListPlot @ Transpose[{FQlist, Rlist}];
DGvsFQ = ListPlot @ Transpose[{FQlist, DGlist}];


Hope it helps a bit.

Victoria


  _______________________________________________________________
  Victoria Steblina                      
  vvs124 at rsphy1.anu.edu.au  
  Optical Sciences Centre                                              
                                                                       
        
  Australian National University                



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