Multiplies all elements of inputVector together, and puts the result into resultVariable. The input vector is left unchanged.

See examples at right.

If any element of inputVector is a missing value ("." or NaN), the result of the entire command will be NaN. If you want to remove NaNs from your vectors, use the CLEAN command.

COPY (12 8 10 4 6 2) data
PRODUCT data dataProduct
PRINT dataProduct

The above program produces the following output:

dataProduct: 46080.0

You can quickly compute a factorial as this example of the factorial of 10:

PRODUCT 1,10 factorial
PRINT factorial

Here is a more practical example:

'Given the data for the annual change in the NASDAQ index,
'analyze it to estimate the range of gains/losses 
'within 1 standard deviation of the mean if you invested
'$10000 in the index and held it for 10 years.
'Also, calculate the probabilities of having a gain 
'and a loss after 10 years.
'For simplicity, ignore costs, dividends, and inflation.
'Data from: http://www.finfacts.com/Private/curency/nasdaqcompositeperformance.htm
'Annual fractional price change of Nasdaq 1930--2006:
COPY (0.1018 0.0173 -0.1733 0.0905 0.2214 \
0.2390 0.3313 -0.1099 0.0553 -0.0924 0.0702 \
0.2284 0.1045 0.0138 -0.0248 0.4553 0.1534 \
0.1135 -0.1850 0.4155 0.0693 -0.0147 0.3166 \
-0.1502 0.2044 0.2312 0.1715 -0.0455 0.2659 \
0.2577 -0.0236 -0.0984 0.2736 0.1718 -0.3106 \
-0.3511 0.2976 0.2610 0.0733 0.1231 0.2811 \
0.3388 -0.0321 0.1867 0.1987 -0.1122 0.3115 \
0.0753 -0.0526 0.1541 0.1926 -0.1780 0.5684 \
0.1545 0.1475 -0.0320 0.3992 0.2271 0.2164 \
0.3963 0.8559 -0.3929 -0.2105 -0.3153 0.5001 \
0.0859 0.0137 -0.0188) nasdaqData

NAME 10 numberOfYears
NAME 10000 initialInvestment
NAME 10000 repeatCount
'Add 1 to the gains to get annual gain factors
ADD 1 nasdaqData nasdaqGainFactors
REPEAT repeatCount
   SAMPLE numberOfYears nasdaqGainFactors sampleHistory
   PRODUCT sampleHistory totalGainFactor
   MULTIPLY initialInvestment totalGainFactor totalGain
   SCORE totalGain gains
END
'Compute median and 1 std dev below median and 1 above:
PERCENTILE gains (15.87 50 84.13) oneStdevRangeOfGains
COUNT gains <initialInvestment howManyLosingPeriods
COUNT gains >initialInvestment howManyGainingPeriods
DIVIDE howManyLosingPeriods repeatCount probabilityOfLoss
DIVIDE howManyGainingPeriods repeatCount probabilityOfGain
PRINT probabilityOfGain probabilityOfLoss
PRINT oneStdevRangeOfGains%8.0F

The above program produces the following output:

probabilityOfGain: 0.9048
probabilityOfLoss: 0.0952
oneStdevRangeOfGains: (12417 24537 45803)