# Change an array by removing all rows that have a particular value in a particular column
**URL:** https://discourse.julialang.org/t/change-an-array-by-removing-all-rows-that-have-a-particular-value-in-a-particular-column/42421
**Category:** New to Julia
**Created:** [July 2, 2020, 9:49am UTC](https://discourse.julialang.org/t/change-an-array-by-removing-all-rows-that-have-a-particular-value-in-a-particular-column/42421 "2020-07-02T09:49:07Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Nash](https://discourse.julialang.org/u/Nash)
#### Post date: [July 2, 2020, 9:49am UTC](https://discourse.julialang.org/t/change-an-array-by-removing-all-rows-that-have-a-particular-value-in-a-particular-column/42421/1 "2020-07-02T09:49:07Z")
Suppose I have an row x col array, called A, for example.
In column 10, say, there are many different values. Some of these are 0. How do I change A so that all rows that contain 0 in column 10 are deleted?
---
### Author:  [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)
#### Post date: [July 2, 2020, 10:01am UTC](https://discourse.julialang.org/t/change-an-array-by-removing-all-rows-that-have-a-particular-value-in-a-particular-column/42421/2 "2020-07-02T10:01:57Z")
- Find all rows that are non-zero in that column using e.g. `rows_to_keep = findall(...)`
- Create a new matrix without those rows by indexing, e.g. `A[rows_to_keep, :]`
- Note, you cannot change the shape of an existing matrix.
---
### Author:  [@baggepinnen](https://discourse.julialang.org/u/baggepinnen)
#### Post date: [July 2, 2020, 10:05am UTC](https://discourse.julialang.org/t/change-an-array-by-removing-all-rows-that-have-a-particular-value-in-a-particular-column/42421/3 "2020-07-02T10:05:02Z")
Try
```julia
rows_to_keep = A[:,10] .!= 0
```