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I don't know how to delete a list from a list.

For example, There is a list.

box[1, 1] = {{50, {5, 3}}, {3.6463, {5, 3}}, {50, {5, 3}}, {50, {5, 3}}, {50, {5, 3}}, {81.490, {5, 3}}, {50, {5, 3}}, {20.2414, {5, 3}}, {42.439, {5, 3}}, {50, {5, 3}}};

select = RandomSample[box[1, 1], Take[5]];

Next, I want to create new list like newbox[1,1] = box[1,1] - select.

For example, If select is

select={{50, {5, 3}}, {42.439, {5, 3}}, {81.490, {5, 3}}, {50, {5, 3}}, {50, {5, 3}}}

, newbox[1,1] should be

newbox[1,1]={{20.2414, {5, 3}},{50, {5, 3}}, {3.6463, {5, 3}},{50, {5, 3}},{50, {5, 3}}}

however, i couldn't make list, I don't understand how to use DeleteCases.for example, I tried

newbox[1, 1] = DeleteCases[box[1, 1], Alternatives @@ select]

but,Alternatives @@ select was incorrect because the same number(here is {50, {5, 3}}) of elements is recognised as one.

What equation should I construct?

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  • $\begingroup$ I hope new list obtained by subtracting "select" from "box[1,1]". $\endgroup$
    – hare
    Commented Nov 3, 2023 at 7:06
  • $\begingroup$ They are not only selects, but also box[1,1] is actually a randomly generated list. I don't want specific values, but I want to avoid that elements with exactly the same value are not considered as one element and are selected in duplicate. $\endgroup$
    – hare
    Commented Nov 3, 2023 at 7:15
  • $\begingroup$ Yes,,,,,,,,,,,,,(, filling up of the minimum number of characters. $\endgroup$
    – hare
    Commented Nov 3, 2023 at 7:26

2 Answers 2

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I am using a slightly modified list:

orig = {{50, {5, 3}}, {3.6463, {5, 3}}, {51, {5, 3}}, {50, {5, 
     3}}, {52, {5, 3}}, {81.490, {5, 3}}, {50, {5, 3}}, {20.2414, {5, 
     3}}, {42.439, {5, 3}}, {49, {5, 3}}};

select = {{50, {5, 3}}, {42.439, {5, 3}}, {81.490, {5, 3}}, {51, {5, 
    3}}, {50, {5, 3}}};

Using Complement: (which treats lists as sets)

Complement[orig, select]

{{3.6463, {5, 3}}, {20.2414, {5, 3}}, {49, {5, 3}}, {52, {5, 3}}}

Using DeleteCases:

DeleteCases[orig, _?(MemberQ[select, #] &)]

{{3.6463, {5, 3}}, {52, {5, 3}}, {20.2414, {5, 3}}, {49, {5, 3}}}

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  • $\begingroup$ I am grateful for your assistance! $\endgroup$
    – hare
    Commented Nov 3, 2023 at 10:18
  • $\begingroup$ @hare, I am glad I was able to help. Thanks for the accept. $\endgroup$
    – Syed
    Commented Nov 3, 2023 at 10:21
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You can use DeleteElements which came with V 13.1

It gives the desired result, but in a slightly different sort order.

 box =
  {{50, {5, 3}}, {3.6463, {5, 3}}, {50, {5, 3}}, {50, {5, 3}},
   {50, {5, 3}}, {81.490, {5, 3}}, {50, {5, 3}}, {20.2414, {5, 3}},
   {42.439, {5, 3}}, {50, {5, 3}}};

select =
 {{50, {5, 3}}, {42.439, {5, 3}}, {81.490, {5, 3}}, {50, {5, 3}}, {50, {5, 3}}};

newbox = DeleteElements[box, 1 -> select]

{{3.6463, {5, 3}}, {50, {5, 3}}, {50, {5, 3}}, {20.2414, {5, 3}}, {50, {5, 3}}}

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  • $\begingroup$ Thank you for your help! $\endgroup$
    – hare
    Commented Nov 3, 2023 at 10:18

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