derivative of scalar

lig · December 23, 2010, 17:43

Hi, All,

Merry Christmas and Happy New Year!

Please help me to get the expression of derivative of scalar d $\Phi$ /dx.

Thanks

lig

akOOma · December 24, 2010, 09:53

You mean in terms of numerical means? Ever heard of finite differences?

Like: f'(x)=(f(x+h)-f(x))/h

or central: f'(x)=(f(x+h)-f(x-h))/2h

lig · December 25, 2010, 15:06

Thank you akOOma. Seems there is no direct code for the derivative of scalar. I will use this basic method. Happy New Year!

akOOma · December 26, 2010, 04:02

If you kow the analytical form of the function you may give an exact derivative. Otherwise you have to use numerical approximations.

December 23, 2010, 17:43	derivative of scalar	#1
lig New Member Gloria Join Date: Feb 2010 Posts: 16 Rep Power: 16	Hi, All, Merry Christmas and Happy New Year! Please help me to get the expression of derivative of scalar d $\Phi$ /dx. Thanks lig

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December 24, 2010, 09:53		#2
akOOma New Member Michael Woopen Join Date: Nov 2010 Location: Aachen, Germany Posts: 12 Rep Power: 15	You mean in terms of numerical means? Ever heard of finite differences? Like: f'(x)=(f(x+h)-f(x))/h or central: f'(x)=(f(x+h)-f(x-h))/2h

December 25, 2010, 15:06		#3
lig New Member Gloria Join Date: Feb 2010 Posts: 16 Rep Power: 16	Thank you akOOma. Seems there is no direct code for the derivative of scalar. I will use this basic method. Happy New Year!

December 26, 2010, 04:02		#4
akOOma New Member Michael Woopen Join Date: Nov 2010 Location: Aachen, Germany Posts: 12 Rep Power: 15	If you kow the analytical form of the function you may give an exact derivative. Otherwise you have to use numerical approximations.