Mathematica 9 is now available
Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Re: Rearranging a data array containing calendrical as well as data entries.

  • To: mathgroup at smc.vnet.net
  • Subject: [mg54888] Re: [mg54865] Re: Rearranging a data array containing calendrical as well as data entries.
  • From: DrBob <drbob at bigfoot.com>
  • Date: Sat, 5 Mar 2005 01:34:32 -0500 (EST)
  • References: <d0614i$krg$1@smc.vnet.net> <200503041008.FAA13123@smc.vnet.net>
  • Reply-to: drbob at bigfoot.com
  • Sender: owner-wri-mathgroup at wolfram.com

A couple of people speculated that the format is fixed-column, and hence the year and month run together for two-digit months. If that's true (or even if it isn't), my earlier solution is easily modified to separate them. Only the first line is changed:

rawData = Import["test.txt", "Table"]
   /. {year_, other__} /; year > 9999 :>
     {Quotient[year, 100], Mod[year, 100], other};

Clear[dateValue, month, twoDigit]
twoDigit[i_Integer?Positive] := StringJoin @@
             PadLeft[Characters@ToString@i, 2, "0"]
month[i_Integer] /; 1 <= i <= 12 := month[i] = {"Jan", "Feb", "Mar",
  "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov",
  "Dec"}[[i]]
dateValue@{yr_, mo_, wk_,
     values___} := Transpose@{twoDigit[# +
         7(wk - 1)] <> month@mo <> ToString@yr & /@
  Range@Length@{values}, {values}}
Flatten[dateValue /@ rawData, 1]

{{01Sep1998, 400.29}, {02Sep1998, 400.29}, {
   03Sep1998, 400.29}, {04Sep1998, 400.29}, {
   05Sep1998, 537.87}, {06Sep1998, 537.87}, {
   07Sep1998, 537.87}, {08Sep1998, 537.87}, {
   08Sep1998, 537.87}, {09Sep1998, 498.97}, {
   10Sep1998, 498.97}, {11Sep1998, 498.97}, {
   12Sep1998, 498.97}, {13Sep1998, 498.97},

et cetera.

Bobby

On Fri, 4 Mar 2005 05:08:01 -0500 (EST), Mark Fisher <mark at markfisher.net> wrote:

> The following code does part of what you want: It reformats the data
> into date/value pairs such as
>
> {{{1991, 1, 1}, 489.82},
> {1991, 1, 2}, 489.82},
> {1991, 1, 3}, 495.01},
> ... }
>
> (* using Version 5.1 *)
> stringlines =
>      Import["http://www.gilmarlily.netfirms.com/download/flow.dat";,
>      "Lines"];
> (* convert strings to numbers *)
> lines = ToExpression[Flatten /@
>      Transpose[{StringTake[stringlines, 4],
>      StringCases[StringDrop[stringlines, 4], NumberString]}]
>      ];
> (* group into months *)
> monthgroups = {#[[1, 1]], Flatten[#[[All, 2]]]} & /@
>      Split[{Take[#, 2], Drop[#, 3]} & /@ lines, #1[[1]] == #2[[1]] &];
> (* reorganize into day/value pairs *)
> pairs = Flatten[Transpose[{Function[x, Append[#[[1]], x]] /@
>      Range[Length[#[[2]]]], #[[2]]}] & /@ monthgroups, 1];
>
> --Mark
>
> Gilmar wrote:
>
>> Dear Mathematica User Friends:
>>
>> I have a file containing flow data from the USGS, in the following
>> format:
>>
>> 1999 1 1 489.82 489.82 495.01 495.01 495.01 495.01 495.01 490.51
>> 1999 1 2 490.51 490.51 490.51 490.51 490.38 490.38 490.38 490.38
>> 1999 1 3 490.38 510.38 510.38 510.38 510.38 510.38 528.66 528.66
>> 1999 1 4 528.66 528.66 528.66 501.68 501.68 501.68 501.68
>> 1999 2 1 501.68 496.44 496.44 496.44 496.44 496.44 478.72 478.72
>> 1999 2 2 478.72 478.72 478.72 452.82 452.82 452.82 452.82 452.82
>> 1999 2 3 450.19 450.19 450.19 450.19 450.19 443.98 443.98 443.98
>> 1999 2 4 443.98 443.98 440.14 440.14
>> 1999 3 1 440.14 440.14 440.14 453.64 453.64 453.64 453.64 453.64
>> 1999 3 2 503.98 503.98 503.98 503.98 503.98 500.84 500.84 500.84
>> 1999 3 3 500.84 500.84 473.48 473.48 473.48 473.48 473.48 463.19
>> 1999 3 4 463.19 463.19 463.19 463.19 457.54 457.54 457.54
>>
>> This format is used by the USGS to compress their data records.
>>
>> Each row contains:
>> Year, Month Number(1 to 12), Row Number (1 to 4), and data entries.
>>
>> The first row:
>> 1999 1 1 489.82 489.82 495.01 495.01 495.01 495.01 495.01 490.51
>> contains flow values corresponding to: January 1 to January 8,
>> of the year 1999.
>>
>> The second row:
>> 1999 1 2 490.51 490.51 490.51 490.51 490.38 490.38 490.38 490.38
>> contains flow values corresponding to: January 9 to January 16,
>> of the year 1999.
>>
>> The third row:
>> 1999 1 3 490.38 510.38 510.38 510.38 510.38 510.38 528.66 528.66
>> contains flow values corresponding to: January 17 to January 24,
>> of the year 1999.
>>
>> The fourth row:
>> 1999 1 4 528.66 528.66 528.66 501.68 501.68 501.68 501.68
>> contains flow values corresponding to: January 25 to January 31,
>> of the year 1999.
>>
>> I think that you get the picture of how this data set is assembled.
>>
>> What I need is a program that can turn the above mentioned horizontal
>> array, into a simple vertical array, containing two columns;
>> the first column contains the dates when the data was collected,
>> and the second column contains the flow values; i.e.
>>
>> 01Jan1999 489.82
>> 02Jan1999 489.82
>> 03Jan1999 495.01
>> etc.
>>
>> If I give the program a starting date, and ending date for an
>> arbitrary record; the program should be able to allocate two
>> arrays to:
>>
>> (1.) put the dates between the starting date, and ending date,
>> to form the first column of the vertical array.
>>
>> (2.)match correctly those dates with the data to appear in
>> the second column of the vertical array.
>>
>> The program should discern between regular years, and leap
>> years.  Those of you that are still using FORTRAN, and have
>> experienced how difficult it is to deal with date functions
>> using FORTRAN, might sympathize with my request.
>>
>> P.S. To get a larger set of USGS flow data to test your program
>> please download the following file:
>>
>> http://www.gilmarlily.netfirms.com/download/flow.dat
>>
>> Thank you for your help!
>>
>
>
>
>



-- 
DrBob at bigfoot.com
www.eclecticdreams.net


  • Prev by Date: Re: defining a recursive formula?
  • Next by Date: Re: Contexts and DumSave
  • Previous by thread: Re: Rearranging a data array containing calendrical as well as data entries.
  • Next by thread: Re: Rearranging a data array containing calendrical as well as data entries.