# NProduct

NProduct[f,{i,imin,imax}]

gives a numerical approximation to the product .

NProduct[f,{i,imin,imax,di}]

uses a step di in the product.

# Details and Options

• NProduct can be used for products with both finite and infinite limits.
• NProduct[f,{i,},{j,},] can be used to evaluate multidimensional products.
• The following options can be given:
•  AccuracyGoal Infinity number of digits of final accuracy sought EvaluationMonitor None expression to evaluate whenever f is evaluated Method Automatic method to use PrecisionGoal Automatic number of digits of final precision sought VerifyConvergence True whether to explicitly test for convergence WorkingPrecision MachinePrecision the precision used in internal computations
• Possible settings for the Method option include:
•  "EulerMaclaurin" Euler–Maclaurin summation method "WynnEpsilon" Wynn epsilon extrapolation method
• With the EulerMaclaurin method, the options AccuracyGoal and PrecisionGoal can be used to specify the accuracy and precision to try and get in the final answer. NProduct stops when the error estimates it gets imply that either the accuracy or precision sought has been reached.
• You should realize that in sufficiently pathological cases, the algorithms used by NProduct can give wrong answers. In most cases, you can test the answer by looking at its sensitivity to changes in the setting of options for NProduct.
• VerifyConvergence is only used for products with infinite limits.
• N[Product[]] calls NProduct.
• NProduct first localizes the values of all variables, then evaluates f with the variables being symbolic, and then repeatedly evaluates the result numerically.
• NProduct has attribute HoldAll, and effectively uses Block to localize variables.

# Examples

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## Basic Examples(1)

Approximate an infinite product numerically:

 In[1]:=
 Out[1]=

The error versus the exact value of :

 In[2]:=
 Out[2]=

# Tutorials

Introduced in 1988
(1.0)