previous array element value?

pableitor · 2021-04-26T14:25:32+00:00

Any idea how to get an arrays variable previous value ? For instance, I tried this silly code: $x[0] = close return $x[0][1] but $x[0][1] which is supposed to be the old value returns the present value same as $x[0]

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04/26/2021 at 3:25 PM #168075 quote
pableitor
Participant

Master
Any idea how to get an arrays variable previous value ? For instance, I tried this silly code:
```
$x[0] = close
return  $x[0][1]
```
but $x[0][1] which is supposed to be the old value returns the present value same as $x[0]
04/26/2021 at 3:43 PM #168078 quote

robertogozzi
Moderator

Legend

It’s not allowed because arrays are not historicized, unlike common variables which allow to see previously retained values.

04/26/2021 at 3:55 PM #168080 quote
robertogozzi
Moderator

Legend
IF you have an array and want to historicize a very few elements, say elements 1 and 4, you can write:
```
$Element[0] = close //$Element[0][1] is not allowed
$Element[1] = high  //$Element[1][1] is not allowed
$Element[2] = close //$Element[2][1] is not allowed
$Element[3] = low   //$Element[3][1] is not allowed
$Element[4] = range //$Element[4][1] is not allowed
a = $Element[1]     //a[1], a[2], ... is allowed to see the history of Element[1]
b = $Element[4]     //b[1], b[2], ... is allowed to see the history of Element[4]
```
(unless you want to use a1, a2, a3,… a1000, provided you have enough time and memory).

pableitor thanked this post
04/26/2021 at 3:56 PM #168081 quote
pableitor
Participant

Master
ok, maybe they reserve the format $x[i][j] for future 2-D arrays. Yes, I found a simple workaround by using temp variables like you said, but it takes memory and time for long vectors:
```
$x[0] = open
$x[1] = close

...

a = $x[0]
b = $x[1]
...

return  a[1], b[1],...
```
04/26/2021 at 4:21 PM #168084 quote

Nicolas
Keymaster

Legend

Historizing arrays would have take more memory than this workaround, considering that the current one dimension array can handle one million column! 🙂
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