In Perl exists a function 'push' to dynamically grow up arrays. Some times
ago I wrote a similiar function in IDL. The function requires the function
datatype.pro from the JHUAPL-IDL-Library.
Both functions are included below.
--Thomas
; ******************************* CUT HERE *******************************
FUNCTION PUSH, oldarr, newvals
;
;+
; NAME:
; PUSH
;
; PURPOSE:
; Pushes new values onto the end of a 1d array. The length of the
; new array increases by the length of the appended array.
; Works like the push - function in PERL. Structure arrays are supported.
;
; CATEGORY:
; Array
;
;
; CALLING SEQUENCE:
; tmparr=push(tmparr,newarr)
;
; INPUTS:
; old array, new array to append
;
; OUTPUTS:
; expanded array
;
;
; RESTRICTIONS:
; Type structure only with named structures, anonymous structures
; will terminate on incompatible type message.
; Requires procedure datatype from the JHUAPL (or idlmeteo) library
;
;
; PROCEDURE:
;
; EXAMPLE:
; IDL> tmparr=['Hanna','Berta','Fritz']
; IDL> print, tmparr
; Hanna Berta Fritz
; IDL> tmparr=push(tmparr,'Heinz')
; IDL> print, tmparr
; Hanna Berta Fritz Heinz
;
; - - - - - - - - - - - - - - - - - - - -
; IDL> tmparr=['Hanna','Berta','Fritz']
; IDL> newarr=['Gustav','Friedrich','Max']
; IDL> tmparr=push(tmparr,newarr)
; IDL> print, tmparr
; Hanna Berta Fritz Gustav Friedrich Max
;
; - - - - - - - - - - - - - - - - - - - -
; IDL> tmparr=[1,2,3]
; IDL> tmparr=push(tmparr,[4,5,6])
; IDL> print, tmparr
; 1 2 3 4 5 6
; - - - - - - - - - - - - - - - - - - - -
; Example for a structure array (database table):
;
; IDL> tmp_attr={name:'', nr:0} ; define attribute
; IDL> tmp_table=replicate(tmp_attr, 100) ; define table
; IDL> tmp_table(10).name='Friedrich' ; insert values
; IDL> tmp_table(10).nr=10
; IDL> new_attr=tmp_table(0) ; define new attr
; ; getting structure
; ; from tmp_table
; IDL> new_attr(0).name='Hans' ; insert values
; IDL> new_attr(0).nr=39
; IDL> tmp_table=push(tmp_table, new_attr)
; IDL> print, 'tmp_table(10): ', tmp_table(10)
; IDL> print, 'tmp_table(100): ', tmp_table(100)
;
; Note: It is required to get the structure for a new attribute from
; the table to which we want to append a new attribute. Just
; defining a new attribute with the same structure wouldn't work
; correctly!
;
; SEE ALSO:
; make_array,boost_array, embed, store_array, reform, mean, makenlog
;
; MODIFICATION HISTORY:
;
; IDLMETEO-Library Swiss Meteorological Institute
;
; Written by: Thomas@Oettli@sma.ch 21-Dec-1992
;
; 04-jan-1993 Th. Oettli - added handling of structure arrays
; - improved performance using array
; operations instead of for loops
; 11-june-1993 Th. Oettli - added note to RESTRICTIONS in
; help section 'anonymous structures'
;
;
;-
type = datatype(oldarr,3)
newdim=n_elements(oldarr)+n_elements(newvals)
old_last=n_elements(oldarr)-1
new_last=newdim-1
CASE type of
'UND': print, 'Could not evaluate datatype!'
'BYT': newarr=make_array(newdim,1, /BYTE)
'INT': newarr=make_array(newdim,1, /INT)
'LON': newarr=make_array(newdim,1, /LON)
'FLT': newarr=make_array(newdim,1, /FLOAT)
'DBL': newarr=make_array(newdim,1, /DOUBLE)
'COMPLEX': newarr=make_array(newdim,1, /COMPLEX)
'STR': newarr=make_array(newdim,1, /STRING)
'STC': newarr=replicate(oldarr(0),newdim)
ENDCASE
newarr(0:old_last)=oldarr(*)
newarr(old_last+1:new_last) = newvals(*)
return, newarr
END
; ********************************** CUT HERE ***********************************
;----------------------------------------------------------- --
;+
; NAME:
; DATATYPE
;
; PURPOSE:
; Datatype of variable as a string (3 char or spelled out).
;
; CATEGORY:
; Type Conversion
;
; CALLING SEQUENCE:
; typ = datatype(var, [flag])
;
; INPUTS:
; var = variable to examine. in
; flag = output format flag (def=0). in
;
; KEYWORD PARAMETERS:
; OUTPUTS:
; typ = datatype string or number. out
; flag = 0 flag = 1 flag = 2 flag = 3
; UND Undefined 0 UND
; BYT Byte 1 BYT
; INT Integer 2 INT
; LON Long 3 LON
; FLO Float 4 FLT
; DOU Double 5 DBL
; COM Complex 6 COMPLEX
; STR String 7 STR
; STC Structure 8 STC
; COMMON BLOCKS:
; NOTES:
; MODIFICATION HISTORY:
; Written by R. Sterner, 24 Oct, 1985.
; RES 29 June, 1988 --- added spelled out TYPE.
; R. Sterner, 13 Dec 1990 --- Added strings and structures.
; R. Sterner, 19 Jun, 1991 --- Added format 3.
; Johns Hopkins University Applied Physics Laboratory.
; Added to idlmeteo from the JHU/APL-Library Nov-1992 oet@sma.ch
;
; Copyright (C) 1985, Johns Hopkins University/Applied Physics Laboratory
; This software may be used, copied, or redistributed as long as it is not
; sold and this copyright notice is reproduced on each copy made. This
; routine is provided as is without any express or implied warranties
; whatsoever. Other limitations apply as described in the file disclaimer.txt.
;-
;----------------------------------------------------------- --
FUNCTION DATATYPE,VAR, FLAG, help=hlp
if (n_params(0) lt 1) or keyword_set(hlp) then begin
print,' Datatype of variable as a string (3 char or spelled out).'
print,' typ = datatype(var, [flag])'
print,' var = variable to examine. in'
print,' flag = output format flag (def=0). in'
print,' typ = datatype string or number. out'
print,' flag=0 flag=1 flag=2 flag=3'
print,' UND Undefined 0 UND'
print,' BYT Byte 1 BYT'
print,' INT Integer 2 INT'
print,' LON Long 3 LON'
print,' FLO Float 4 FLT'
print,' DOU Double 5 DBL'
print,' COM Complex 6 COMPLEX'
print,' STR String 7 STR'
print,' STC Structure 8 STC'
return, -1
endif
IF N_PARAMS(0) LT 2 THEN FLAG = 0 ; Default flag.
if n_elements(var) eq 0 then begin
s = [0,0]
endif else begin
S = SIZE(VAR)
endelse
if flag eq 2 then return, s(s(0)+1)
IF FLAG EQ 0 THEN BEGIN
CASE S(S(0)+1) OF
0: TYP = 'UND'
7: TYP = 'STR'
1: TYP = 'BYT'
2: TYP = 'INT'
4: TYP = 'FLO'
3: TYP = 'LON'
5: TYP = 'DOU'
6: TYP = 'COM'
7: TYP = 'STR'
8: TYP = 'STC'
ELSE: PRINT,'Error in DATATYPE'
ENDCASE
ENDIF ELSE if flag eq 1 then BEGIN
CASE S(S(0)+1) OF
0: TYP = 'Undefined'
7: TYP = 'String'
1: TYP = 'Byte'
2: TYP = 'Integer'
4: TYP = 'Float'
3: TYP = 'Long'
5: TYP = 'Double'
6: TYP = 'Complex'
7: TYP = 'String'
8: TYP = 'Structure'
ELSE: PRINT,'Error in DATATYPE'
ENDCASE
ENDif else IF FLAG EQ 3 THEN BEGIN
CASE S(S(0)+1) OF
0: TYP = 'UND'
7: TYP = 'STR'
1: TYP = 'BYT'
2: TYP = 'INT'
4: TYP = 'FLT'
3: TYP = 'LON'
5: TYP = 'DBL'
6: TYP = 'COMPLEX'
7: TYP = 'STR'
8: TYP = 'STC'
ELSE: PRINT,'Error in DATATYPE'
ENDCASE
endif
RETURN, TYP
END
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