# Calc : function rand() side effect on cells values [closed]

I'm novice to LibreOffice and just done a fresh install on my ArchLinux system. Here is the up-to-date version of LibreOffice i have :

Version: 5.0.5.2 Build ID: 5.0.5.2 Arch Linux build-1 Locale: en-US (en_US.UTF-8)

Willing to learn the very basics of spreadsheets, i opened a new spreadsheet document, and starting using the rand() function within cells formulas. For example, i set one cell with =rand() formula, and then copy down the formula to the cells below, and then to the cells at the next column to make an array of random values.

What is surprising, and i want to understand is, when i modify one cell on this spreadsheet, whatever the cell is, all cells containing random values (with =rand() formula), are modified.

I would like to understand this behavior.

Thanks.

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### Closed for the following reason the question is answered, right answer was accepted by Alex Kemp close date 2020-09-01 20:02:46.840521

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Hallo

RAND() is designed to be volatile… eg. it recalculate itself on any other calculation in the same sheet.
If you want to avoid this behavior use sth. like =RANDBETWEEN(1;10000)/10000 which returns roughly the same, but recalculates only on forced recalculation ( <ctrl><shift><F9> )

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Hallo karolus,

You put me on the right path, because i nearly thought it could be a bug, but thinking about it then thought i had missed something. Thanks for the replacement function, i will use it. Now i will be more carefull about how functions are defined (volatile or not for example).

( 2016-03-17 13:45:38 +0200 )edit

I could find this as the official documentation of LO Calc relative to mathematical functions, but it doesn't make any reference to volatile property that you mentioned :

Mathematical Functions - LibreOffice Help

I would be great to read somewhere a more complete definition of rand() function.

( 2016-03-18 09:32:19 +0200 )edit

Say for example, if i have for the A4:C8 cells, entered the formula "=rand()", to randomize an array 3x5 of values, if i just set one cell elsewhere (E1 for example) on the spreadsheet with a value , it will affect all the values of the A4:C8 range of cells.

Say :

0.7208296846 0.9681026701 0.1170904948 0.4816458312 0.2473452087 0.2533566935 0.1701826189 0.4916606066 0.28557925 0.2569225257 0.6591033325 0.9558581608 0.9941591621 0.5651747689 0.6260274619

Become

0.9184627659 0.8902114319 0.3679129528 2 0.8269501603 0.7634500963 0.5624116682
0.217940301 0.4380287969 0.668961365
0.5994510901 0.7790492607 0.9111794242
0.6082804288 0.787962539 0.5868770138

more