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Better way to test the number of arguments?

• To: mathgroup at smc.vnet.net
• Subject: [mg132642] Better way to test the number of arguments?
• From: pgeipi10 at gmail.com
• Date: Sun, 27 Apr 2014 02:42:25 -0400 (EDT)
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Hi,

I have the following code that produces the gradient of a function (with respect to all but the first variable). There is probably a better way that avoids the Switch.

Thank you,

Pavel

ddSaPartial[func_][t_, s__] := Switch[Length[{s}],
  1, {Derivative[0, 1][func][t, s]},
  2, {Derivative[0, 1, 0][func][t, s], 
   Derivative[0, 0, 1][func][t, s]},
  3, {Derivative[0, 1, 0, 0][func][t, s], 
   Derivative[0, 0, 1, 0][func][t, s], 
   Derivative[0, 0, 0, 1][func][t, s]},
  4, {Derivative[0, 1, 0, 0, 0][func][t, s], 
   Derivative[0, 0, 1, 0, 0][func][t, s], 
   Derivative[0, 0, 0, 1, 0][func][t, s], 
   Derivative[0, 0, 0, 0, 1][func][t, s]},
  5, {Derivative[0, 1, 0, 0, 0, 0][func][t, s], 
   Derivative[0, 0, 1, 0, 0, 0][func][t, s], 
   Derivative[0, 0, 0, 1, 0, 0][func][t, s], 
   Derivative[0, 0, 0, 0, 1, 0][func][t, s], 
   Derivative[0, 0, 0, 0, 0, 1][func][t, s]}
  

• Follow-Ups:
  • Re: Better way to test the number of arguments?
    • From: Bob Hanlon <hanlonr357@gmail.com>
  • Re: Better way to test the number of arguments?
    • From: Pavel Grinfeld <pgeipi10@gmail.com>
  • Re: Better way to test the number of arguments?
    • From: Bob Hanlon <hanlonr357@gmail.com>
  • Re: Better way to test the number of arguments?
    • From: Bob Hanlon <hanlonr357@gmail.com>