Random Number In PowerBuilder

//////////////////////////////////////////////////////////////////////// //
// Function: f_BigRand
//
// Description:
// This function uses 2 calls to Rand to generate Random numbers for large
// ranges. It breaks the range into blocks of 32767 (max range for
// RAND function)
// The limit of the function is 32767 blocks of 32767.
// It calls RAND to first determine which block, then calls RAND again to
// determine the number in the
// selected block. To ensure even probability over the range where
//  there are multiple blocks,
// the same sub range is used for each block.
//
// Argument al_range
// The upper limit of the range of random numbers you want returned.
// The lower limit is always 1. The maximum value for the argument is
// 1,073,676,289 or 32767*32767.
//
// Returns
// A random number in the range 1 to al_range inclusive.
// Or 0 if max range exceeded.
//
//////////////////////////////////////////////////////////////////////////
//
// Revision History
//
// -----------------------------------------------------------------------
// VERSION CHANGE ID WHO WHEN WHAT/WHY
// -----------------------------------------------------------------------
// 6.30 8/4/00 Initial version.
//////////////////////////////////////////////////////////////////////////
Long ll_Offset, ll_Return
Integer li_Range, li_Blocks

// Block size is set to 32767 as this is the maximum range
// the RAND function can handle
Integer li_BlockSize = 32767

If al_range > 1073676289 Then
	//Range is too big
	Return 0
End If

//Determine The number of blocks
li_Blocks = Truncate(al_range/li_BlockSize,0)

//Add an extra block to accommodate any remainder
If Mod(al_range, li_BlockSize) > 0 Then
	li_Blocks = li_Blocks + 1
End If

// Improve efficiency for ranges less than Block Size
// where there is only one block
If al_range < li_BlockSize Then
	li_Range = al_range
Else
	li_Range = li_BlockSize
End If

ll_Return = 0

// Loop until the value is in range.
// If the value is not in range, calculate the
// Offset again to ensure even probability
Do Until (ll_Return > 0) And (ll_Return <= al_range)
	// Calculate a Random Offset using the number
	// of blocks as the range.
	// Offsets will range from [0 to (li_Blocks - 1)*BlockSize]
	// in increments of BlockSize
	ll_Offset = (Rand(li_Blocks) - 1) * li_BlockSize

	//Main Calculation
	ll_Return = ll_Offset + Rand(li_Range)
Loop

Return ll_Return

//////////////////////////////////////////////////////////////////////// //

// Function: f_BigRand

// Description:

// This function uses 2 calls to Rand to generate Random numbers for large

// ranges. It breaks the range into blocks of 32767 (max range for

// RAND function)

// The limit of the function is 32767 blocks of 32767.

// It calls RAND to first determine which block, then calls RAND again to

// determine the number in the

// selected block. To ensure even probability over the range where

// there are multiple blocks,

// the same sub range is used for each block.

// Argument al_range

// The upper limit of the range of random numbers you want returned.

// The lower limit is always 1. The maximum value for the argument is

// 1,073,676,289 or 32767*32767.

// Returns

// A random number in the range 1 to al_range inclusive.

// Or 0 if max range exceeded.

//////////////////////////////////////////////////////////////////////////

// Revision History

// -----------------------------------------------------------------------

// VERSION CHANGE ID WHO WHEN WHAT/WHY

// -----------------------------------------------------------------------

// 6.30 8/4/00 Initial version.

//////////////////////////////////////////////////////////////////////////

Long ll_Offset, ll_Return

Integer li_Range, li_Blocks

// Block size is set to 32767 as this is the maximum range

// the RAND function can handle

Integer li_BlockSize = 32767

If al_range > 1073676289 Then

//Range is too big

Return 0

End If

//Determine The number of blocks

li_Blocks = Truncate(al_range/li_BlockSize,0)

//Add an extra block to accommodate any remainder

If Mod(al_range, li_BlockSize) > 0 Then

li_Blocks = li_Blocks + 1

End If

// Improve efficiency for ranges less than Block Size

// where there is only one block

If al_range < li_BlockSize Then

li_Range = al_range

Else

li_Range = li_BlockSize

End If

ll_Return = 0

// Loop until the value is in range.

// If the value is not in range, calculate the

// Offset again to ensure even probability

Do Until (ll_Return > 0) And (ll_Return <= al_range)

// Calculate a Random Offset using the number

// of blocks as the range.

// Offsets will range from [0 to (li_Blocks - 1)*BlockSize]

// in increments of BlockSize

ll_Offset = (Rand(li_Blocks) - 1) * li_BlockSize

//Main Calculation

ll_Return = ll_Offset + Rand(li_Range)

Loop

Return ll_Return

Good Luck! From Source: pbdr.com

PowerBuilder Tips & Tricks

November 21, 2020

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