DjangoBB LoFi version

Full Version: array: remove same values?

Root » Houdini Indie and Apprentice » array: remove same values?

olivierth

Feb. 5, 2019 23:50:48

Hi!

If I have an array like this:

{0,1,2,2,7,9,9,9,33}

…How can I remove all the same values to end up with:

(0,1,2,7,9,33)

?

-Olivier

bonsak

Feb. 6, 2019 03:31:20

You could do it in python:

geo = hou.pwd().geometry()

my_list = geo.intListAttribValue('my_list') # Get the detail attribute
no_duplicates = list(set(my_list)) # Remove duplicates
geo.setGlobalAttribValue('my_list', no_duplicates) # Store the new values

This example runs in a Python SOP and the geo is just one point with a detail array attribute

-b

olivierth

Feb. 6, 2019 09:11:28

Thanks but I'm looking for a Vex solution. I'm new to coding so i'd like to keep it simple by staying with Vex.

-Olivier

BabaJ

Feb. 6, 2019 10:50:37

Yes…in a wrangle set to detail:

//i[]@List = {4,5,8,8,2,3,0,1};
//i[]@List   = {4,4,8,8,2,3,8,4,8};
i[]@List   = {1,8,8,2,7,3,8,4,8,6,7,1,1};


int Count, Count_A;


for(Count = 0; Count < len(i[]@List); Count++)
    {
    for(Count_A = 0; Count_A < len(i[]@List); Count_A++)
        {
        if( (i[]@List[Count] == i[]@List[Count_A]) && (Count != Count_A) )
            {
            removeindex(i@List, Count_A);
            }
        }
    }

olivierth

Feb. 6, 2019 12:40:58

That's more complicated than I expected!

Thanks, I'll use this very soon.

-Olivier

BabaJ

Feb. 7, 2019 17:17:13

In case your interested…maybe if this is the only code in a wrangle that one is going to use…it's not too bad that it's ‘complicated’…but if your going to need to do other things in the same wrangle, what I like to do as in this case where I know as in this case, that this code is like to be used elsewhere, is to make it an ‘external’ function.

So with the above what you could do is copy and paste into a text file, with some modifications to make it like this:

int[] Remove_Duplicate_Array_Items(int Imported_Array[])
{
int List[];
int Count, Count_A;

List = Imported_Array;

for(Count = 0; Count < len(List); Count++)
    {
    for(Count_A = 0; Count_A < len(List); Count_A++)
        {
        if( (List[Count] == List[Count_A]) && (Count != Count_A) )
            {
            removeindex(List, Count_A);
            }
        }
    }

return List;
}

Then save it as a text file with an extension of your preference…I like to use *.h as personal convention.

For my project, because I work as a ‘freelancer’ and not in a production team I tend to keep all files within/reference to the project $HIP directory.

In that directory I create a folder named ‘vex’ and within that folder another one named ‘include’ within that I place the above file/s with my .h extensions.

Then in any wrangle of my project file the first line is as follows:

#include <Remove_Duplicate_Array_Items.h>

and after that I only need to use one line to make use of the function which keeps it looking simpler to read and add more code/other functions:

#include <Remove_Duplicate_Array_Items.h>

//i[]@List = {4,5,8,8,2,3,0,1};
//i[]@List   = {4,4,8,8,2,3,8,4,8};
i[]@List   = {1,8,8,2,7,3,8,4,8,6,7,1,1};


i[]@List = Remove_Duplicate_Array_Items(i[]@List);

Also, just to be clear of another convention I do…I tend to name the text file (with the .h extension) the same name as the function…for easy and quickly identifying my needs since if I want to use other functions I may have created is just a matter of adding additional #include lines:

#include <Remove_Duplicate_Array_Items.h>
#include <Another_One_Of_My_Functions.h>
#include <One_Thousand_Line_Function.h>

//Happy coding here;

olivierth

Feb. 8, 2019 07:59:47

Wow, that's very cool! I'm only a beginner in Houdini so this might be too advanced for the simple personal tests I'm doing. That being said, it's nice that you can create your own functions! It's like creating digital assets for vex coding!

Cheers!

-Olivier

Fele

Sept. 29, 2021 06:29:26

I was just looking for vex solution and found this thread...
Just in case anyone else is looking for this, maybe here is another, shorter solution:

f[]@myarray = {1,1,1,2,2,3,4,5,5,5,6,7,7,7,8,8,9};

float current;
float next;

for(int i = len(@myarray); i > -1; i--)
    {
    current = @myarray[i];
    next = @myarray[i-1];
    if(current == next)
        {
        removeindex(@myarray, i);
        }
    }

Another way could be to assign a value like "0" to the duplicate values instead of removing..

evrstudio

March 20, 2022 05:03:31

you can also do this way:

int origLs = {1,1,1,2,2,3,4,5,5,5,6,7,7,7,8,8,9};
int setOrigLs = array();
foreach(int orig; origLs)
{
if (find(setOrigLs, orig) < 0)
append(setOrigLs, orig);
}
origLs = setOrigLs;

josyzhaocn

July 4, 2022 03:11:22

evrstudio
you can also do this way:

int origLs = {1,1,1,2,2,3,4,5,5,5,6,7,7,7,8,8,9};
int setOrigLs = array();
foreach(int orig; origLs)
{
if (find(setOrigLs, orig) < 0)
append(setOrigLs, orig);
}
origLs = setOrigLs;

This worked for me. Really smart!

OdFotan

July 22, 2022 11:44:52

Thank you.

int origLs[] = {1,1,1,2,2,3,4,5,5,5,6,7,7,7,8,8,9};
int setOrigLs[];
foreach(int orig; origLs){
    if (find(setOrigLs, orig) < 0) append(setOrigLs, orig);
}
origLs = setOrigLs;

Kareeem

March 3, 2025 07:42:39

OdFotan
Thank you.

int origLs[] = {1,1,1,2,2,3,4,5,5,5,6,7,7,7,8,8,9};
int setOrigLs[];
foreach(int orig; origLs){
    if (find(setOrigLs, orig) < 0) append(setOrigLs, orig);
}
origLs = setOrigLs;

I am trying to understand this... Is the following description correct?

In the first iteration of the loop we check if orig ( in this case 1) is in the array setOrigLs. Wich it is not. Therefore the find function returns -1. Wich is smaller then 0. Therefore we append orig (1 ) to setOrigLs.

In the second iteration we check again if orig ( still 1) is in setOrigLs . This time it is and therefore nothing gets appended.

Tanto

March 3, 2025 09:12:37

Yes, that's exactly what's happening.

Kareeem

March 3, 2025 13:04:11

Tanto
Yes, that's exactly what's happening.

Cool, thank you!

This is really smooth coding!