internal rate of return

Internal Rate of Return: PHP Class

Each item in array of cash flows has date and amount.

dates (first item): any representation of date

Automatically converts / to -
If no dates specified start at 2000-01-01 and add year to each one
If all 0s then start at 2000-01-01 and add year to each one
If no dashes and up to 7 digits, this is number of days beginning 2000-01-01
If dashes and first item 1 or 2 digits, this is mm-dd-yyyy or mm-dd-yy
If dashes and first item 4 digits, this is yyyy-mm-dd
Dates do not have to be in order, they will be sorted
Any invalid dates will be ignored

amounts (second item) is positive for purchases, negative for distributions and sales

Any sale/distribution followed by purchase treated as reinvestment
Any bad data, including 0 amounts, will be ignored

To calculate performance after investment has been purchased, just specify a purchase on the desired beginning date using the value of the investment on that date.
For instance, if you already owned 100 shares of stock XYZ on 1/1/2000, when it was trading at $10 per share, but wanted to calculate performance beginning on that date, specify cash flow of 1000.00 (positive, purchase) on 2000-01-01.

To calculate peformance while investment is still being held, just specify a sale on the desired end date using the value of the investment on that date.
For instance, if you still held stock XYZ on 12/31/2000, which it was trading at $10 per share, but wanted to calculate performance as of that date, specify a cash flow of -1000.00 (negative, sale) on 2000-12-31.

Thus, if you had the following cash flows:

12/01/1999 $1000 purchase (100 shares at $10)
01/01/2000    $5 dividend
01/01/2000    $5 reinvestment (bought .5 shares)
04/01/2000    $5 dividend
04/01/2000    $5 reinvestment (bought .5 shares)
07/01/2000    $5 dividend
07/01/2000    $5 reinvestment (bought .5 shares)
10/01/2000    $5 dividend
10/01/2000    $5 reinvestment (bought .5 shares)
12/31/2000    (still held 100 shares but now at $11)

The cash flow array would be:

$flows = array(array('date'=>'12/1/1999', 'amount'=>1000),    
         array('date'=>'1/1/2000', 'amount'=>-5), array('date'=>'1/1/2000', 'amount'=>5),      
         array('date'=>'4/1/2000', 'amount'=>-5), array('date'=>'4/1/2000', 'amount'=>5),      
         array('date'=>'7/1/2000', 'amount'=>-5), array('date'=>'7/1/2000', 'amount'=>5),      
         array('date'=>'10/1/2000','amount'=>-5), array('date'=>'10/1/2000', 'amount'=>5),      
         array('date'=>'12/31/2000', 'amount'=>-1100));

To create array of cash flows:

$flows = array(array('date'=>date, 'amount'=>amount), array('date'=>date,'amount'=>amount) ...);

To instantiate object:

$perf = new DLCCalculatePerformance($flows);

To get internal rate of return:

$irr = $perf->CalculateIRR();

To get performance over the period:

$ret = $perf->CalculatePerformance();

To get annual performance without consideration of time:

$rate = $perf->CalculatePerformanceRate();

To get total input amount (purchases) of flows: $input = $perf->CalculateInputAmount(); To get total output amount (sales/distributions) of flows:

$output = $perf->CalculateOutputAmount();

To get input amount adjustments for reinvestments:

$adj = $perf->CalculateInputAmountAdjustment();

To get the number of days for the cash flows:

$days = $perf->GetMaxDays();

Download PHP Internal Rate of Return Class and Test Page

Internal Rate of Return: Apex (Salesforce) Class

Two arrays, dates and amounts, represent cash flows.

dates (first array): any representation of date

Automatically converts / to -
If no dates specified start at 2000-01-01 and add year to each one
If all 0s then start at 2000-01-01 and add year to each one
If no dashes and up to 7 digits, this is number of days beginning 2000-01-01
If dashes and first item 1 or 2 digits, this is mm-dd-yyyy or mm-dd-yy
If dashes and first item 4 digits, this is yyyy-mm-dd
Dates do not have to be in order, they will be sorted
Any invalid dates will be ignored

amounts (second array) is positive for purchases, negative for distributions and sales

Any sale/distribution followed by purchase treated as reinvestment
Any bad data, including 0 amounts, will be ignored

  12/01/1999 $1000 purchase (100 shares at $10)
  01/01/2000    $5 dividend
  01/01/2000    $5 reinvestment (bought .5 shares)
  04/01/2000    $5 dividend
  04/01/2000    $5 reinvestment (bought .5 shares) 
  07/01/2000    $5 dividend
  07/01/2000    $5 reinvestment (bought .5 shares) 
  10/01/2000    $5 dividend
  10/01/2000    $5 reinvestment (bought .5 shares) 
  12/31/2000    (still held 100 shares but now at $11)

The cash flow arrays would be:

  String[] Dates = new String[]{'12/1/1999', '1/1/2000', '1/1/2000', '4/1/2000', '4/1/2000', 
                       '7/1/2000', '7/1/2000', '10/1/2000', '10/1/2000', '12/31/2000'};
  Double[] Amounts = new Double[]{1000, -5, 5, -5, 5, -5, 5, -5, 5, -1100};

To create arrays of dates and amounts:

String[] Dates = new String[]{'1/1/2001','7/1/2002',..};
  Double[] Amounts = new Double[]{-6,-18,...};

To instantiate object:

DLCCalculatePerformance perf = new DLCCalculatePerformance(Dates,Amounts);

To get internal rate of return:

Double irr = perf.CalculateIRR();

To get performance over the period:

Double ret = perf.CalculatePerformance();

To get annual performance without consideration of time:

Double rate = perf.CalculatePerformanceRate();

To get total input amount (purchases) of flows:

Double input = perf.CalculateInputAmount();

To get total output amount (sales/distributions) of flows:

Double output = perf.CalculateOutputAmount();

To get input amount adjustments for reinvestments:

Double adj = perf.CalculateInputAmountAdjustment();

To get the number of days for the cash flows:

Integer days = perf.GetMaxDays();

Download Apex/Salesforce Internal Rate of Return Class and Test Page

Dave Cohen -
Alleycat Software

Web Development

Dave Cohen - Alleycat Software

Web Development

Dave Cohen -
Alleycat Software