Entry
BBCBASIC: Windows: Array: Maximum: How to determine the maximum value of an array?
Feb 2nd, 2006 17:30
Knud van Eeden,
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--- Knud van Eeden --- 02 February 2006 - 11:04 pm -------------------
BBCBASIC: Windows: Array: Maximum: How to determine the maximum value
of an array?
===
Method: Set the maximum at first to a smallest value possible
---
Steps: Overview:
1. -Let a variable contain the maximum
2. -Set this variable equal to some minimum value
(e.g. the minimum value possible for this variable
type (e.g. integer))
3. -Search linearly through the array
(and so check against all values in the array)
1. -For first to last value in the array
1. -Read the value
2. -If this value is greater than the current maximum
set the maximum equal to this value
2. -Endfor
4. The resulting value will be the maximum
===
Steps: Worked out:
1. -Create the following program
--- cut here: begin --------------------------------------------------
maxR = 0
minI% = 1
maxI% = 5
I% = 0
:
DIM xR( maxI% )
:
FOR I% = minI% TO maxI%
READ xR( I% )
NEXT I%
:
REM determine the maximum
maxR = -1E9 : REM initialize maximum to a smallest minimum value
:
FOR I% = minI% TO maxI%
IF ( xR( I% ) > maxR ) THEN maxR = xR( I% )
NEXT I%
:
PRINT "maximum = "; maxR
:
END
:
:
:
DATA 43
DATA 2
DATA 789
DATA 9999
DATA 6
:
--- cut here: end ----------------------------------------------------
2. -If you run this program it will show
maximum = 9999
===
Method: Set the maximum at first equal to the first element in the
array
This method has as an advantage that it is directly dependent
on the dataset.
===
Steps: Worked out:
1. -Create the following program
--- cut here: begin --------------------------------------------------
maxR = 0
minI% = 1
maxI% = 5
I% = 0
:
DIM xR( maxI% )
:
FOR I% = minI% TO maxI%
READ xR( I% )
NEXT I%
:
REM determine the maximum
maxR = xR( minI% ) : REM set maximum at first equal to first element
:
FOR I% = minI% TO maxI%
IF ( xR( I% ) > maxR ) THEN maxR = xR( I% )
NEXT I%
:
PRINT "maximum = "; maxR
:
END
:
:
:
DATA 43
DATA 2
DATA 789
DATA 9999
DATA 6
:
--- cut here: end ----------------------------------------------------
2. -If you run this program it will show
maximum = 9999
===
In the following example you pass your array to a function
(using string concatenation)
--- cut here: begin --------------------------------------------------
minI% = 1
maxI% = 5
I% = 0
:
DIM xR( maxI% )
:
FOR I% = minI% TO maxI%
READ xR( I% )
NEXT I%
:
PRINT "maximum = "; FNArrayGetMaximumR( minI%, maxI%, "xR(", ")" )
:
END
:
:
:
REM library: determine the maximum
DEF FNArrayGetMaximumR( minI%, maxI%, arrayBegin$, arrayEnd$ )
LOCAL maxR
LOCAL xR
maxR = EVAL( arrayBegin$ + STR$( minI% ) + arrayEnd$ ) : REM set
maximum at first equal to first element
:
FOR I% = minI% TO maxI%
xR = EVAL( arrayBegin$ + STR$( I% ) + arrayEnd$ )
IF xR > maxR THEN maxR = xR
NEXT I%
= maxR
:
DATA 43
DATA 2
DATA 789
DATA 9999
DATA 6
:
--- cut here: end ----------------------------------------------------
2. -If you run this program it will show
maximum = 9999
===
In the following example you pass your array to a function
(using direct passing)
--- cut here: begin --------------------------------------------------
minI% = 1
maxI% = 5
I% = 0
:
DIM xR( maxI% )
:
FOR I% = minI% TO maxI%
READ xR( I% )
NEXT I%
:
PRINT "maximum = "; FNArrayGetMaximumR( minI%, maxI%, "xR(", ")" )
:
END
:
:
:
REM library: determine the maximum
DEF FNArrayGetMaximumR( minI%, maxI%, arrayBegin$, arrayEnd$ )
LOCAL maxR
LOCAL xR
maxR = EVAL( arrayBegin$ + STR$( minI% ) + arrayEnd$ ) : REM set
maximum at first equal to first element
:
FOR I% = minI% TO maxI%
xR = EVAL( arrayBegin$ + STR$( I% ) + arrayEnd$ )
IF xR > maxR THEN maxR = xR
NEXT I%
= maxR
:
DATA 43
DATA 2
DATA 789
DATA 9999
DATA 6
:
--- cut here: end ----------------------------------------------------
2. -If you run this program it will show
maximum = 9999
---
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Internet: see also:
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BBCBASIC: Windows: Array: Function: How to pass an array to a function?
http://www.faqts.com/knowledge_base/view.phtml/aid/39453/fid/768
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