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Student Support Forum: 'Writing to array using variable with address' topicStudent Support Forum > General > Archives > "Writing to array using variable with address"

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Author Comment/Response
Nasser M. Abbasi
06/29/12 07:29am


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First, I have a multi-dimensional array (let's call it "array1") and I don't know a priori how many dimensions it has.
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Use Dimensions[] to find the size

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Second, I have an address of some element of array1 and it looks like:
address1={2,2,1,5,3,1};
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These are called positions, or indices, not address. There are no pointers in Mathematica.

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I know that I can extract this element using such code:
(array1[[##]] & @@@ {address1})[[1]]
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I do not understand this code.

To read element at position pos from array A, simply type

A[[pos]]

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It will work just like "array1[[2,2,1,5,3,1]]". But the next line is not going to work:
(array1[[##]] & @@@ {address1})[[1]] = 15;
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To assign a value to a list at position pos type

A[[pos]=value

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That is my question. How to change the value of an element of array1 which can be found using address1?
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Use [[ ]] Or Part.

If given position in pos, something like

Map[Part[A, Sequence @@ #] &, pos]

see my note on basic examples using Mathematica arrays here

http://12000.org/my_notes/mma_matlab_control/KERNEL/node66.htm



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Subject (listing for 'Writing to array using variable with address')
Author Date Posted
Writing to array using variable with address Leon 06/28/12 04:52am
Re: Writing to array using variable with address Nasser M. Ab... 06/29/12 07:29am
Re: Re: Writing to array using variable with ad... Leon 06/29/12 09:48am
Re: Re: Re: Writing to array using variable wit... Nasser M. Ab... 06/29/12 1:07pm
Re: Writing to array using variable with address Michael 07/02/12 00:43am
Re: Re: Writing to array using variable with ad... Leon 07/02/12 10:56am
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