# DiffEq Plotting Question

**URL:** <https://discourse.julialang.org/t/diffeq-plotting-question/123228>\
**Category:** General Usage\
**Tags:** plotting, diffeq\
**Created:** [November 28, 2024, 8:07pm UTC](https://discourse.julialang.org/t/diffeq-plotting-question/123228 "2024-11-28T20:07:33Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![TheLazyFarmer](https://avatars.discourse-cdn.com/v4/letter/t/87869e/32.png) [@TheLazyFarmer](https://discourse.julialang.org/u/TheLazyFarmer)\
**Post date:** [November 28, 2024, 8:07pm UTC](https://discourse.julialang.org/t/diffeq-plotting-question/123228/1 "2024-11-28T20:07:33Z")

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Hello, I have the results of a differential equation I solved with DifferentialEquations.jl. Each of the results of the solution are stored in an (n x n+1) array, as so:

```julia
4×5 Matrix{Float64}:
 -1.0 -1.0 -1.0 -1.0 0.0
 -1.0 -1.0 -1.0 9.89029e-11 1.90176e-17
 -1.0 -1.0 1681.92 0.00290038 1.72268e-10
  6.022e23 2.86406e17 4.22592e10 12482.0 0.000225923

```

I was wondering if would be possible to isolate specific values from all of the equations to be plotted.  
The reason why is primarily due to the -1.0’s, which I used as a placeholder since I don’t actually need to solve them, and I don’t know what to use otherwise as a placeholder since NaN breaks the solver.

Primarily, the point is to be able to have a log plot for all the positive values (and any 0’s if they appear), but with the negatives I can’t really do that.

If anyone has any ideas to solve my problem I would greatly appreciate it!

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<div class="post-metadata">

**Author:** ![ChrisRackauckas](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/chrisrackauckas/32/77_2.png) [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)\
**Post date:** [November 29, 2024, 6:04am UTC](https://discourse.julialang.org/t/diffeq-plotting-question/123228/2 "2024-11-29T06:04:28Z")

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`plot(sol, idxs = [1,6,9])` using column-order indexing.