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Carlo Pagani · 26 Oct 2009, 02:51 AM

Input requires separate variables for each item that is to be read.
You can try
INPUT #1, little%(1,1,1), little%(1,1,2), little%(1,2,1), little%(1,2,2)....
or something along those lines.

Tiziano Magni · 26 Oct 2009, 04:20 AM

retrieving column-major ordered arrays

Search the help file for GET and PUT in binary files.

To write the array to a file:

Code:

DIM little%(2,3,2) 
OPEN "little_table.tab" FOR BINARY AS #1
PUT #1, ,little%()
CLOSE #1

To reload the array from a file:

Code:

DIM little%(2,3,2) 
OPEN "little_table.tab" FOR BINARY AS #1
GET #1, ,little%()
CLOSE #1

P.S. Why you have posted in "Using the forums" instead of "PowerBASIC for Windows" or "PowerBASIC Console Compiler"?

Lucien Preuss · 29 Oct 2009, 01:55 PM

Sincere Thanks to Pagani and Magni for their answers.
However, the problem is more difficult than it looks. Pagani’s suggestion seems unpractical when the array has hundreds of elements. As for Magni’s proposal to use PUT and GET, I suppose he is on the right track, but his solution does not work in its present form, and I was unable to improve it in spite of many attempts. Maybe the suggested simple PUT procedure actually works, but I doubt it. Anyhow, this can not be checked before the GET procedure is in proper order, because only PB and VB can read (and hence check) the proprietary “packed string format” of the binary file (Manual p.381). A kind of Catch 22.

The GET procedure probably requires using the FILESCAN statement, but I could not find out how this must be done for a multidimensional array. The Manual is cryptic about it, as it concentrate on strings (which have a meaningful overall length), and on individual records of lists (which have a precise location), so that I am at a loss about how to include into the GET procedure both the number of dimensions and the extent of each dimension in a multidimensional array. Maybe even the PUT procedure must contain an explicit specification of these parameters.

Has anybody an idea? Otherwise I must, as a last resort, ask somebody from the inner circle.

PS. The simple answer to Magni’s question is: because I am a tyro in these matters – I never wrote a single line in a Forum or the like before. I hope you will pardon me and I promise to amend

.

Manuel Valdes · 29 Oct 2009, 02:51 PM

Lucien:

This is the general form to store and retrieve a multidimensional array in binary format. You have to calculate the size of the full array, having into consideration that the number of elements is the dimension plus 1, and the size of the variables you use (short integer in this case=2: 2*101*4*5=4040)

Best regards,

Code:

 
#COMPILE EXE
#DIM ALL
FUNCTION PBMAIN () AS LONG
 LOCAL LT%(),II%,IJ%,KK%
 DIM LT%(100,3,4)
 FOR II%=1 TO 100
  FOR IJ%=1 TO 3
   FOR KK%=1 TO 4
    LT%(II%,IJ%,KK%)=II%*IJ%*KK%
   NEXT
  NEXT
 NEXT
 OPEN "ARR.BIN" FOR BINARY AS #1
 PUT #1,4040,LT%()
 CLOSE 1
 
 REDIM LT%(100,3,4)   'clear the values in memory 
 PRINT LT%(38,3,4)     'verify
 PRINT LT%(67,2,3)
 
 
 OPEN "ARR.BIN" FOR BINARY AS #1
  GET #1,4040,LT%()              'retrieve the full array
 CLOSE 1
 PRINT LT%(38,3,4)               ' verify
 PRINT LT%(67,2,3)
 PRINT LT%(100,3,4)
 WAITKEY$
END FUNCTION

Michael Mattias · 29 Oct 2009, 04:00 PM

Code:

FOR II%=1 TO 100
  FOR IJ%=1 TO 3
   FOR KK%=1 TO 4
    LT%(II%,IJ%,KK%)=II%*IJ%*KK%
   NEXT
  NEXT
 NEXT

Wow.

Why don't you get lazy?

Code:

Storage =   ARRAYATTR(array(), 4) * ARRAYATTR(array(),5) 
'                -----------------------   ------------------------
'                 total elements               size of element

MCM

Tiziano Magni · 29 Oct 2009, 05:15 PM

Lucien,

Maybe I didn't understand what you try to do

If you want to write and then read the array values, the following example in PBCC 5.02 does it using PUT and GET.
Note that the dimensions of the array are fixed.

Code:

#COMPILE EXE
#DIM ALL

FUNCTION PBMAIN () AS LONG
    ' Write an array to a file with PUT instruction then read
    ' the saved values into another array with GET instruction
    '
    DIM littlewrite(2,3,2) AS INTEGER, littleread(2,3,2) AS INTEGER
    DIM i AS INTEGER, j AS INTEGER, k AS INTEGER
    '
    PRINT "Assign values 101 - 136 to the array..."
    ARRAY ASSIGN littlewrite() = 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111, 112, _
                            113, 114, 115, 116, 117, 118, 119, 120, 121, 122, 123, 124, _
                            125, 126, 127, 128, 129, 130, 131, 132, 133, 134, 135, 136
    FOR i = LBOUND(littlewrite, 1) TO UBOUND(littlewrite, 1)
      FOR j = LBOUND(littlewrite, 2) TO UBOUND(littlewrite, 2)
        FOR k = LBOUND(littlewrite, 3) TO UBOUND(littlewrite, 3)
          PRINT littlewrite(i, j, k); $SPC;
        NEXT k
        PRINT
      NEXT j
      PRINT
    NEXT i
    PRINT
    ' write array values to file
    OPEN "little_table.tab" FOR BINARY AS #1
    PUT #1, ,littlewrite()
    CLOSE #1
    ' read array values from file
    OPEN "little_table.tab" FOR BINARY AS #1
    GET #1, , littleread()
    CLOSE #1
    '
    PRINT
    PRINT "Values from file..."
    FOR i = LBOUND(littleread, 1) TO UBOUND(littleread, 1)
      FOR j = LBOUND(littleread, 2) TO UBOUND(littleread, 2)
        FOR k = LBOUND(littleread, 3) TO UBOUND(littleread, 3)
          PRINT littleread(i, j, k); $SPC;
        NEXT k
        PRINT
      NEXT j
      PRINT
    NEXT i
    '
    WAITKEY$
    '
END FUNCTION

P.S. The FILESCAN instruction works only with variable length string data!

Quoting the help file:

FILESCAN statement
PURPOSE - Rapidly scan a file opened for INPUT or BINARY mode, in order to obtain size information about variable length string data
RESTRICTIONS - If FILESCAN is applied to other file formats, the results are undefined.

Tiziano Magni

Lucien Preuss · 30 Oct 2009, 09:50 AM

Huge thanks to all, what a wonderful and fast as lightning crowd you are at PowerBasic.

Manuel’s listing is an outstanding mixture of knowledge and commonsense. It worked immediately. Apart from offering a solution for a very disturbing problem, it made me ashamed because I missed the automatic method which he uses to fill up an array through multiplications at each trial. This is sooo much more comfortable than my own little trial program which forced me to enter check numbers through the keyboard at each run! I will use Manuel’s method for many future checks.

Michael’s suggestion to use ARRAYATTR for evaluating the size of the array seems valuable too. I did not try it out yet, but it looks very useful, not so much for lazyness as for flexibility when an application requires arrays of different sizes. It seems regrettable that the manual does not mention ARRAYATTR under the heading “see also…” at the end of the entry for FILESCAN.

Sincere thanks again, and two final questions:
¿ why does Manuel prefer REDIM to RESET which I used hitherto for emptying arrays ?
¿ Is PB’s binary format some kind of standard, or particular to PB and VB ? This is of interest in cases where a user wishes to enter an array of empirical data into an existing PB application. It is fairly easy to tell a physicist or a statistician how to fill a “column-major” array with his or her data, but much more of a problem to explain the transformation of the data into some obscure, not readily available “binary format”.

Michael Mattias · 30 Oct 2009, 10:19 AM

Save/Load 'n-dimension' array of anything to/from disk

Pseudo-code only

Given: MyArray(), nDimensions, some datatype

Code:

SaveME: 

    OPEN  "myFile" fOR BINARY AS hFile 
    PUT    hFile, ARRAYATTR (myarray(), 1)  ' save datatype
    PUT    hFile, ARRAYATTR( myArray(), 5)  ' save element size 
    nDimension = ARRAYATTR(myarray(),  3)
    PUT    hFile, , nDimension    ' save number of dimensions
    FOR Z = 1 TO ndimension
       PUT    hFile,,LBOUND(myArray,Z)      'save LBOUND/UBOUND of each dimension
       PUT    hFile, UBOUND (myarray, Z)
   NEXT 
   PUT hFile,,myArray()    ' save array data 


LoadMe: 

   OPEN "myFile" FOR BINARY as hFile 
   GET   hFile, , DataType
   Get   hFile,,  ElSize
   GET   hFile,,  nDimension 
   REDIM lb(nDimension), ub(Dimension) 
   FOR Z = 1 TO nDimension 
       GET  hFile,, LB(Z)
       GEt  hFiie,, UB(Z) 
   NEXT 
  ' Here is where it gets really ugly with a variable number 
  ' of dimensions, since you need a separate REDIM statement 
  ' for each possible number of dimensions and datatype 

   eg  
   SELECT CASE nDimension 
         CASE 1 
            REDIM mArray( lb(1) TO ub(1) AS BYTE
         CASE 2 
           REDIM myArray (Lb(1) TO ub(1), lb(2) TO Ub(2)) 
          ....
          CASE n   
             REDIM myArray (Lb(1) TO ub(1), lb(2) TO Ub(2)...., lb(n) TO ub(n)

   END SELECT 
   GET   hFile,,MyArray()   ' load the data

I have never tried it, but instead of doing all possible combinations of datatype and number of dimensions, it might be possible to use the technique shown here...
Single Function to process any array type (CC3/Win7+) 12-17-03
.. to effect a REDIM "as a different datatype"

The doc says you can't change the number of dimensions, but does not say you can't change the datatype.

I think in the real world however, applications are NOT going to be dealing with a variable number of dimensions or "any" datatype, so you could cut down this code to support the number of dimensions and datatypes for this application.

Heck, it's a starting point.
MCM

Manuel Valdes · 30 Oct 2009, 10:58 AM

Lucien:

I am very glad being able to help you, as I am very grateful for what I can learn every day here in PB Forums.

REDIM is a better choice since ERASE deallocate your previous DIMming so following an ERASE you have to DIM it again. If you simply want to clear the content of the array without changing it's dimensions then you can use RESET instead. REDIM can also be used with the PRESERVE option, so you can change the dimensioning of the ARRAY preserving it's content.

As far as I know every Basic compiler have the capacity of handling files as Binary.

Best regards,

Michael Mattias · 31 Oct 2009, 09:48 AM

>As far as I know every Basic compiler have the capacity of handling files as Binary

And if it doesn't....

Code:

  OPEN "file" FOR RANDOM as #762  [COLOR="Red"][b]LEN=1[/b][/COLOR]

MCM

Dave Biggs · 1 Nov 2009, 11:32 AM

¿ Is PB’s binary format some kind of standard, or..

PB stores Array Data in Column Major order.
Using PUT with Binary files, string array data is written to disk with a size value before each dynamic string element.
See this thread for more info on how to Save / Read arrays of string data using either PUT / GET or PRINT / LINE INPUT..
http://www.powerbasic.com/support/pb...ad.php?t=41125

To explore how integer values are handled, I've modified Manuel's original sample code a little below.
The test uses a small 3-dimensional array to see how the data is written to disk..

Code:

' PBWin or PBCC
#COMPILE EXE
#DIM ALL
#INCLUDE "win32API.inc"                     ' For MessageBox()
 
FUNCTION PBMAIN () AS LONG
 LOCAL LT%(), II%, IJ%, IK%, Temp?()
 DIM LT%(1,2,2) 
 LOCAL FileLen&&, Count&, Elements&
 
  FOR II% = 0 TO 1
   FOR IJ% = 0 TO 2
    FOR IK% = 0 TO 2
     LT%(II%,IJ%,IK%) = II%*100 + IJ%*10 + IK%   ' 0,1,2,10,11,12,20,21,22,100,101,102 etc
    NEXT
   NEXT
  NEXT
 
  KILL "ARR.BIN"                            ' Fresh file each time
  OPEN "ARR.BIN" FOR BINARY AS #1
  ' PUT [#] fNum&, [RecPos], Arr()          ' Note - RecPos is optional 
    PUT #1,,LT%()                           ' start writing at first position in file if not used.
  CLOSE #1
 
  OPEN "ARR.BIN" FOR BINARY AS #1
    FileLen&& = LOF(#1) : MessageBox 0, "File Length:" + str$(FileLen&&) + " Bytes","LOF from file",0 
    REDIM Temp?(FileLen&&)                  ' For test - uses one dimensional array to retrieve data
  ' GET [#] filenum&, [RecPos], Arr() [RECORDS rcds] [TO count]
    GET #1,,Temp?() TO Count&               ' retrieve the full array data and count the Bytes read
                                            ' (FileLen should = Count, the number of bytes in file)
  CLOSE #1
 
  RESET LT%()                               ' Clear array data
  Elements& = ARRAYATTR(LT%(), 4)           ' With mods array params could be saved with & retrieved from file data?
  REDIM LT%(1,2,2) AT VarPtr(Temp?(0))      ' Overlay an Integer array with appropriate dimensions.
                                            ' NB: Number and size of array dimensions must be correct !!
  MessageBox 0, "Data from file." + $CR + _
                "Array Val: (1,1,2) =" + str$(LT%(1,1,2)), "Array Elements:" + str$(Elements&), 0 ' verify
END FUNCTION
'------------------/
#IF 0
 Data derived from nested for-next loops:
 0,1,2,10,11,12,20,21,22,100,101,102,110,111,112,120,121,122
 
 Integers are stored in memory as two bytes per value in 'LSB, MSB' order.
 Array values are stored in memory and PUT to file in Column Major order:
 (Using hex editor to read ARR.BIN..)
  000000  00 00 64 00 0a 00 6e 00 14 00 78 00   0,100, 10,110, 20,120
  00000c  01 00 65 00 0b 00 6f 00 15 00 79 00   1,101, 11,111, 21,121
  000018  02 00 66 00 0c 00 70 00 16 00 7a 00   2,102, 12,112, 22,122
 
 PB's GET statement is used to rewrite file data to memory.
#ENDIF

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retrieving column-major ordered arrays

retrieving column-major ordered arrays

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