---
# System prepended metadata

title: Plot APE for VIOX (MATLAB)
tags: [Work]

---

---
title: 'Plot APE for VIOX (MATLAB)'
disqus: hackmd
---

Plot APE for VIOX (MATLAB)
===


## Table of Contents

[TOC]

## Prerequest
We need **Matlab** & **evo** for plotting APE
### Matlab
* step1. Download  [Matlab](https://www.mathworks.com/products/matlab.html)
* step2. Install it~
* step3. Download the [Matlab code](https://drive.google.com/drive/folders/1vgDVrpcNskH4qEJZmByjIgWHVpiZn-8O?usp=sharing) for verification
### evo
* step1. git clone [evo](https://github.com/MichaelGrupp/evo) 
```C++
git clone https://github.com/MichaelGrupp/evo.git
```
* step2. Setting up evo (**need pip3 installed**)
    * step2-1. [pip3 installation](https://linuxize.com/post/how-to-install-pip-on-ubuntu-18.04/)
        ```C++
        sudo apt update
        ```
        ```C++
        sudo apt install python3-pip
        ```   
        Check if you install sucessfully
        ```C++
        pip3 --version
        ```
    * step2-2. Setting up evo
        ```C++
        pip3 install --editable . --upgrade --no-binary evo
        ```

## Verfify
* step1. Run **viox**, and you shoud get **gps_raw.csv** & **pose.csv** in the output folder
* step2. Run **evo_llh2xyz.m** in Matlab
    * Change your **gps_raw.csv** path 
        ```C++
        gps_path = '/path/to/gps_raw.csv';
        gps_out_path = '/path/to/saving/gps.txt';
        ```
    * Change your **pose.csv** path 
        ```C++
        VIO_path = /path/to/pose.csv';
        VIO_out_path ='/path/to/saving/vio.txt';
        ```
* step3. Run **evo** 
    1. For comparing gps & vio, **evo_ape** is avaliable, and the command is something like
     ```C++
     evo_ape tum reference_file estimate_file -p -va
     ```
      
     * EX.
         ```C++
         evo_ape tum gps.txt vio.txt -p -va
         ```
    2. For comparing gps & vio1 & vio2, only **evo_traj** is avaliable, and the command is something like
     ```C++
     evo_traj tum estimate_file1 estimate_file2 --ref=reference_file -p --va
     ```
    * EX.
         ```C++
         evo_traj tum vio1.txt vio2.txt --ref=gps.txt -p --va
         ```
    3. For comparing gps & vio1 & vio2 using evo_ape, please see [this example](https://github.com/MichaelGrupp/evo)
![](https://i.imgur.com/wqqpMtV.png)

* Results. You shoud get something like the two pics showing bellow
![](https://i.imgur.com/yM5tPx9.png)
![](https://i.imgur.com/ycrG2Bu.png)




###### tags: `Work`
